diff options
Diffstat (limited to 'release/src/router/busybox/shell/hush.c')
| -rw-r--r-- | release/src/router/busybox/shell/hush.c | 8926 |
1 files changed, 6599 insertions, 2327 deletions
diff --git a/release/src/router/busybox/shell/hush.c b/release/src/router/busybox/shell/hush.c index 84818ffa..83515906 100644 --- a/release/src/router/busybox/shell/hush.c +++ b/release/src/router/busybox/shell/hush.c @@ -1,18 +1,19 @@ /* vi: set sw=4 ts=4: */ /* - * sh.c -- a prototype Bourne shell grammar parser - * Intended to follow the original Thompson and Ritchie - * "small and simple is beautiful" philosophy, which - * incidentally is a good match to today's BusyBox. + * A prototype Bourne shell grammar parser. + * Intended to follow the original Thompson and Ritchie + * "small and simple is beautiful" philosophy, which + * incidentally is a good match to today's BusyBox. * - * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org> + * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org> + * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com> * * Credits: * The parser routines proper are all original material, first * written Dec 2000 and Jan 2001 by Larry Doolittle. The * execution engine, the builtins, and much of the underlying * support has been adapted from busybox-0.49pre's lash, which is - * Copyright (C) 1999-2003 by Erik Andersen <andersen@codepoet.org> + * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org> * written by Erik Andersen <andersen@codepoet.org>. That, in turn, * is based in part on ladsh.c, by Michael K. Johnson and Erik W. * Troan, which they placed in the public domain. I don't know @@ -20,11 +21,10 @@ * rewrites. * * Other credits: - * simple_itoa() was lifted from boa-0.93.15 - * b_addchr() derived from similar w_addchar function in glibc-2.2 - * setup_redirect(), redirect_opt_num(), and big chunks of main() - * and many builtins derived from contributions by Erik Andersen - * miscellaneous bugfixes from Matt Kraai + * o_addchr derived from similar w_addchar function in glibc-2.2. + * parse_redirect, redirect_opt_num, and big chunks of main + * and many builtins derived from contributions by Erik Andersen. + * Miscellaneous bugfixes from Matt Kraai. * * There are two big (and related) architecture differences between * this parser and the lash parser. One is that this version is @@ -37,827 +37,1458 @@ * handle the recursion implicit in the various substitutions, especially * across continuation lines. * - * Bash grammar not implemented: (how many of these were in original sh?) - * $@ (those sure look like weird quoting rules) - * $_ - * ! negation operator for pipes - * &> and >& redirection of stdout+stderr - * Brace Expansion - * Tilde Expansion - * fancy forms of Parameter Expansion + * POSIX syntax not implemented: * aliases - * Arithmetic Expansion * <(list) and >(list) Process Substitution - * reserved words: case, esac, select, function - * Here Documents ( << word ) - * Functions - * Major bugs: - * job handling woefully incomplete and buggy - * reserved word execution woefully incomplete and buggy - * to-do: - * port selected bugfixes from post-0.49 busybox lash - done? - * finish implementing reserved words: for, while, until, do, done - * change { and } from special chars to reserved words - * builtins: break, continue, eval, return, set, trap, ulimit - * test magic exec - * handle children going into background - * clean up recognition of null pipes - * check setting of global_argc and global_argv - * control-C handling, probably with longjmp - * follow IFS rules more precisely, including update semantics - * figure out what to do with backslash-newline - * explain why we use signal instead of sigaction - * propagate syntax errors, die on resource errors? - * continuation lines, both explicit and implicit - done? - * memory leak finding and plugging - done? - * more testing, especially quoting rules and redirection - * document how quoting rules not precisely followed for variable assignments - * maybe change map[] to use 2-bit entries - * (eventually) remove all the printf's + * Tilde Expansion * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. + * Bash stuff (maybe optionally enable?): + * &> and >& redirection of stdout+stderr + * Brace expansion + * reserved words: [[ ]] function select + * substrings ${var:1:5} * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License for more details. + * TODOs: + * grep for "TODO" and fix (some of them are easy) + * builtins: ulimit + * follow IFS rules more precisely, including update semantics * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * Licensed under the GPL v2 or later, see the file LICENSE in this tarball. */ -#include <ctype.h> /* isalpha, isdigit */ -#include <unistd.h> /* getpid */ -#include <stdlib.h> /* getenv, atoi */ -#include <string.h> /* strchr */ -#include <stdio.h> /* popen etc. */ -#include <glob.h> /* glob, of course */ -#include <stdarg.h> /* va_list */ -#include <errno.h> -#include <fcntl.h> -#include <getopt.h> /* should be pretty obvious */ - -#include <sys/stat.h> /* ulimit */ -#include <sys/types.h> -#include <sys/wait.h> -#include <signal.h> - +#include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */ +#include <glob.h> /* #include <dmalloc.h> */ -/* #define DEBUG_SHELL */ +#if ENABLE_HUSH_CASE +# include <fnmatch.h> +#endif +#include "math.h" +#include "match.h" +#ifndef PIPE_BUF +# define PIPE_BUF 4096 /* amount of buffering in a pipe */ +#endif + + +/* Build knobs */ +#define LEAK_HUNTING 0 +#define BUILD_AS_NOMMU 0 +/* Enable/disable sanity checks. Ok to enable in production, + * only adds a bit of bloat. Set to >1 to get non-production level verbosity. + * Keeping 1 for now even in released versions. + */ +#define HUSH_DEBUG 1 +/* Slightly bigger (+200 bytes), but faster hush. + * So far it only enables a trick with counting SIGCHLDs and forks, + * which allows us to do fewer waitpid's. + * (we can detect a case where neither forks were done nor SIGCHLDs happened + * and therefore waitpid will return the same result as last time) + */ +#define ENABLE_HUSH_FAST 0 + + +#if BUILD_AS_NOMMU +# undef BB_MMU +# undef USE_FOR_NOMMU +# undef USE_FOR_MMU +# define BB_MMU 0 +# define USE_FOR_NOMMU(...) __VA_ARGS__ +# define USE_FOR_MMU(...) +#endif + +#if defined SINGLE_APPLET_MAIN +/* STANDALONE does not make sense, and won't compile */ +# undef CONFIG_FEATURE_SH_STANDALONE +# undef ENABLE_FEATURE_SH_STANDALONE +# undef USE_FEATURE_SH_STANDALONE +# define USE_FEATURE_SH_STANDALONE(...) +# define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__ +# define ENABLE_FEATURE_SH_STANDALONE 0 +#endif + +#if !ENABLE_HUSH_INTERACTIVE +# undef ENABLE_FEATURE_EDITING +# define ENABLE_FEATURE_EDITING 0 +# undef ENABLE_FEATURE_EDITING_FANCY_PROMPT +# define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0 +#endif -#if 1 -#include "busybox.h" -#include "cmdedit.h" +/* Do we support ANY keywords? */ +#if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE +# define HAS_KEYWORDS 1 +# define IF_HAS_KEYWORDS(...) __VA_ARGS__ +# define IF_HAS_NO_KEYWORDS(...) #else -#define bb_applet_name "hush" -#include "standalone.h" -#define hush_main main -#undef CONFIG_FEATURE_SH_FANCY_PROMPT -#define BB_BANNER -#endif -#define SPECIAL_VAR_SYMBOL 03 -#define FLAG_EXIT_FROM_LOOP 1 -#define FLAG_PARSE_SEMICOLON (1 << 1) /* symbol ';' is special for parser */ -#define FLAG_REPARSING (1 << 2) /* >=2nd pass */ - -typedef enum { +# define HAS_KEYWORDS 0 +# define IF_HAS_KEYWORDS(...) +# define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__ +#endif + +/* If you comment out one of these below, it will be #defined later + * to perform debug printfs to stderr: */ +#define debug_printf(...) do {} while (0) +/* Finer-grained debug switches */ +#define debug_printf_parse(...) do {} while (0) +#define debug_print_tree(a, b) do {} while (0) +#define debug_printf_exec(...) do {} while (0) +#define debug_printf_env(...) do {} while (0) +#define debug_printf_jobs(...) do {} while (0) +#define debug_printf_expand(...) do {} while (0) +#define debug_printf_glob(...) do {} while (0) +#define debug_printf_list(...) do {} while (0) +#define debug_printf_subst(...) do {} while (0) +#define debug_printf_clean(...) do {} while (0) + +#define ERR_PTR ((void*)(long)1) + +#define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n" + +#define SPECIAL_VAR_SYMBOL 3 + +struct variable; + +static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER; + +/* This supports saving pointers malloced in vfork child, + * to be freed in the parent. + */ +#if !BB_MMU +typedef struct nommu_save_t { + char **new_env; + struct variable *old_vars; + char **argv; + char **argv_from_re_execing; +} nommu_save_t; +#endif + +/* The descrip member of this structure is only used to make + * debugging output pretty */ +static const struct { + int mode; + signed char default_fd; + char descrip[3]; +} redir_table[] = { + { 0, 0, "??" }, + { O_RDONLY, 0, "<" }, + { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" }, + { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" }, + { O_RDONLY, 0, "<<" }, + { O_CREAT|O_RDWR, 1, "<>" }, +/* Should not be needed. Bogus default_fd helps in debugging */ +/* { O_RDONLY, 77, "<<" }, */ +}; + +typedef enum reserved_style { + RES_NONE = 0, +#if ENABLE_HUSH_IF + RES_IF , + RES_THEN , + RES_ELIF , + RES_ELSE , + RES_FI , +#endif +#if ENABLE_HUSH_LOOPS + RES_FOR , + RES_WHILE , + RES_UNTIL , + RES_DO , + RES_DONE , +#endif +#if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE + RES_IN , +#endif +#if ENABLE_HUSH_CASE + RES_CASE , + /* three pseudo-keywords support contrived "case" syntax: */ + RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */ + RES_MATCH , /* "word)" */ + RES_CASE_BODY, /* "this command is inside CASE" */ + RES_ESAC , +#endif + RES_XXXX , + RES_SNTX +} reserved_style; + +typedef struct o_string { + char *data; + int length; /* position where data is appended */ + int maxlen; + /* Protect newly added chars against globbing + * (by prepending \ to *, ?, [, \) */ + smallint o_escape; + smallint o_glob; + /* At least some part of the string was inside '' or "", + * possibly empty one: word"", wo''rd etc. */ + smallint o_quoted; + smallint has_empty_slot; + smallint o_assignment; /* 0:maybe, 1:yes, 2:no */ +} o_string; +enum { + MAYBE_ASSIGNMENT = 0, + DEFINITELY_ASSIGNMENT = 1, + NOT_ASSIGNMENT = 2, + WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */ +}; +/* Used for initialization: o_string foo = NULL_O_STRING; */ +#define NULL_O_STRING { NULL } + +/* I can almost use ordinary FILE*. Is open_memstream() universally + * available? Where is it documented? */ +typedef struct in_str { + const char *p; + /* eof_flag=1: last char in ->p is really an EOF */ + char eof_flag; /* meaningless if ->p == NULL */ + char peek_buf[2]; +#if ENABLE_HUSH_INTERACTIVE + smallint promptme; + smallint promptmode; /* 0: PS1, 1: PS2 */ +#endif + FILE *file; + int (*get) (struct in_str *); + int (*peek) (struct in_str *); +} in_str; +#define i_getch(input) ((input)->get(input)) +#define i_peek(input) ((input)->peek(input)) + +struct redir_struct { + struct redir_struct *next; + char *rd_filename; /* filename */ + int rd_fd; /* fd to redirect */ + /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */ + int rd_dup; + smallint rd_type; /* (enum redir_type) */ + /* note: for heredocs, rd_filename contains heredoc delimiter, + * and subsequently heredoc itself; and rd_dup is a bitmask: + * 1: do we need to trim leading tabs? + * 2: is heredoc quoted (<<'delim' syntax) ? + */ +}; +typedef enum redir_type { + REDIRECT_INVALID = 0, REDIRECT_INPUT = 1, REDIRECT_OVERWRITE = 2, REDIRECT_APPEND = 3, - REDIRECT_HEREIS = 4, - REDIRECT_IO = 5 + REDIRECT_HEREDOC = 4, + REDIRECT_IO = 5, + REDIRECT_HEREDOC2 = 6, /* REDIRECT_HEREDOC after heredoc is loaded */ + + REDIRFD_CLOSE = -3, + REDIRFD_SYNTAX_ERR = -2, + REDIRFD_TO_FILE = -1, + /* otherwise, rd_fd is redirected to rd_dup */ + + HEREDOC_SKIPTABS = 1, + HEREDOC_QUOTED = 2, } redir_type; -/* The descrip member of this structure is only used to make debugging - * output pretty */ -struct {int mode; int default_fd; char *descrip;} redir_table[] = { - { 0, 0, "()" }, - { O_RDONLY, 0, "<" }, - { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" }, - { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" }, - { O_RDONLY, -1, "<<" }, - { O_RDWR, 1, "<>" } + +struct command { + pid_t pid; /* 0 if exited */ + int assignment_cnt; /* how many argv[i] are assignments? */ + smallint is_stopped; /* is the command currently running? */ + smallint grp_type; /* GRP_xxx */ +#define GRP_NORMAL 0 +#define GRP_SUBSHELL 1 +#if ENABLE_HUSH_FUNCTIONS +# define GRP_FUNCTION 2 +#endif + /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */ + struct pipe *group; +#if !BB_MMU + char *group_as_string; +#endif +#if ENABLE_HUSH_FUNCTIONS + struct function *child_func; +/* This field is used to prevent a bug here: + * while...do f1() {a;}; f1; f1 {b;}; f1; done + * When we execute "f1() {a;}" cmd, we create new function and clear + * cmd->group, cmd->group_as_string, cmd->argv[0]. + * when we execute "f1 {b;}", we notice that f1 exists, + * and that it's "parent cmd" struct is still "alive", + * we put those fields back into cmd->xxx + * (struct function has ->parent_cmd ptr to facilitate that). + * When we loop back, we can execute "f1() {a;}" again and set f1 correctly. + * Without this trick, loop would execute a;b;b;b;... + * instead of correct sequence a;b;a;b;... + * When command is freed, it severs the link + * (sets ->child_func->parent_cmd to NULL). + */ +#endif + char **argv; /* command name and arguments */ +/* argv vector may contain variable references (^Cvar^C, ^C0^C etc) + * and on execution these are substituted with their values. + * Substitution can make _several_ words out of one argv[n]! + * Example: argv[0]=='.^C*^C.' here: echo .$*. + * References of the form ^C`cmd arg^C are `cmd arg` substitutions. + */ + struct redir_struct *redirects; /* I/O redirections */ }; +/* Is there anything in this command at all? */ +#define IS_NULL_CMD(cmd) \ + (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects) + -typedef enum { +struct pipe { + struct pipe *next; + int num_cmds; /* total number of commands in pipe */ + int alive_cmds; /* number of commands running (not exited) */ + int stopped_cmds; /* number of commands alive, but stopped */ +#if ENABLE_HUSH_JOB + int jobid; /* job number */ + pid_t pgrp; /* process group ID for the job */ + char *cmdtext; /* name of job */ +#endif + struct command *cmds; /* array of commands in pipe */ + smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */ + IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */ + IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */ +}; +typedef enum pipe_style { PIPE_SEQ = 1, PIPE_AND = 2, PIPE_OR = 3, PIPE_BG = 4, } pipe_style; - -/* might eventually control execution */ -typedef enum { - RES_NONE = 0, - RES_IF = 1, - RES_THEN = 2, - RES_ELIF = 3, - RES_ELSE = 4, - RES_FI = 5, - RES_FOR = 6, - RES_WHILE = 7, - RES_UNTIL = 8, - RES_DO = 9, - RES_DONE = 10, - RES_XXXX = 11, - RES_IN = 12, - RES_SNTX = 13 -} reserved_style; -#define FLAG_END (1<<RES_NONE) -#define FLAG_IF (1<<RES_IF) -#define FLAG_THEN (1<<RES_THEN) -#define FLAG_ELIF (1<<RES_ELIF) -#define FLAG_ELSE (1<<RES_ELSE) -#define FLAG_FI (1<<RES_FI) -#define FLAG_FOR (1<<RES_FOR) -#define FLAG_WHILE (1<<RES_WHILE) -#define FLAG_UNTIL (1<<RES_UNTIL) -#define FLAG_DO (1<<RES_DO) -#define FLAG_DONE (1<<RES_DONE) -#define FLAG_IN (1<<RES_IN) -#define FLAG_START (1<<RES_XXXX) +/* Is there anything in this pipe at all? */ +#define IS_NULL_PIPE(pi) \ + ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE)) /* This holds pointers to the various results of parsing */ -struct p_context { - struct child_prog *child; +struct parse_context { + /* linked list of pipes */ struct pipe *list_head; + /* last pipe (being constructed right now) */ struct pipe *pipe; + /* last command in pipe (being constructed right now) */ + struct command *command; + /* last redirect in command->redirects list */ struct redir_struct *pending_redirect; - reserved_style w; - int old_flag; /* for figuring out valid reserved words */ - struct p_context *stack; - int type; /* define type of parser : ";$" common or special symbol */ - /* How about quoting status? */ +#if !BB_MMU + o_string as_string; +#endif +#if HAS_KEYWORDS + smallint ctx_res_w; + smallint ctx_inverted; /* "! cmd | cmd" */ +#if ENABLE_HUSH_CASE + smallint ctx_dsemicolon; /* ";;" seen */ +#endif + /* bitmask of FLAG_xxx, for figuring out valid reserved words */ + int old_flag; + /* group we are enclosed in: + * example: "if pipe1; pipe2; then pipe3; fi" + * when we see "if" or "then", we malloc and copy current context, + * and make ->stack point to it. then we parse pipeN. + * when closing "then" / fi" / whatever is found, + * we move list_head into ->stack->command->group, + * copy ->stack into current context, and delete ->stack. + * (parsing of { list } and ( list ) doesn't use this method) + */ + struct parse_context *stack; +#endif }; -struct redir_struct { - redir_type type; /* type of redirection */ - int fd; /* file descriptor being redirected */ - int dup; /* -1, or file descriptor being duplicated */ - struct redir_struct *next; /* pointer to the next redirect in the list */ - glob_t word; /* *word.gl_pathv is the filename */ +/* On program start, environ points to initial environment. + * putenv adds new pointers into it, unsetenv removes them. + * Neither of these (de)allocates the strings. + * setenv allocates new strings in malloc space and does putenv, + * and thus setenv is unusable (leaky) for shell's purposes */ +#define setenv(...) setenv_is_leaky_dont_use() +struct variable { + struct variable *next; + char *varstr; /* points to "name=" portion */ + int max_len; /* if > 0, name is part of initial env; else name is malloced */ + smallint flg_export; /* putenv should be done on this var */ + smallint flg_read_only; }; -struct child_prog { - pid_t pid; /* 0 if exited */ - char **argv; /* program name and arguments */ - struct pipe *group; /* if non-NULL, first in group or subshell */ - int subshell; /* flag, non-zero if group must be forked */ - struct redir_struct *redirects; /* I/O redirections */ - glob_t glob_result; /* result of parameter globbing */ - int is_stopped; /* is the program currently running? */ - struct pipe *family; /* pointer back to the child's parent pipe */ - int sp; /* number of SPECIAL_VAR_SYMBOL */ - int type; +enum { + BC_BREAK = 1, + BC_CONTINUE = 2, }; -struct pipe { - int jobid; /* job number */ - int num_progs; /* total number of programs in job */ - int running_progs; /* number of programs running */ - char *text; /* name of job */ - char *cmdbuf; /* buffer various argv's point into */ - pid_t pgrp; /* process group ID for the job */ - struct child_prog *progs; /* array of commands in pipe */ - struct pipe *next; /* to track background commands */ - int stopped_progs; /* number of programs alive, but stopped */ - int job_context; /* bitmask defining current context */ - pipe_style followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */ - reserved_style r_mode; /* supports if, for, while, until */ +#if ENABLE_HUSH_FUNCTIONS +struct function { + struct function *next; + char *name; + struct command *parent_cmd; + struct pipe *body; +#if !BB_MMU + char *body_as_string; +#endif }; +#endif -struct close_me { - int fd; - struct close_me *next; -}; -struct variables { - char *name; - char *value; - int flg_export; - int flg_read_only; - struct variables *next; +/* "Globals" within this file */ +/* Sorted roughly by size (smaller offsets == smaller code) */ +struct globals { + /* interactive_fd != 0 means we are an interactive shell. + * If we are, then saved_tty_pgrp can also be != 0, meaning + * that controlling tty is available. With saved_tty_pgrp == 0, + * job control still works, but terminal signals + * (^C, ^Z, ^Y, ^\) won't work at all, and background + * process groups can only be created with "cmd &". + * With saved_tty_pgrp != 0, hush will use tcsetpgrp() + * to give tty to the foreground process group, + * and will take it back when the group is stopped (^Z) + * or killed (^C). + */ +#if ENABLE_HUSH_INTERACTIVE + /* 'interactive_fd' is a fd# open to ctty, if we have one + * _AND_ if we decided to act interactively */ + int interactive_fd; + const char *PS1; + const char *PS2; +# define G_interactive_fd (G.interactive_fd) +#else +# define G_interactive_fd 0 +#endif +#if ENABLE_FEATURE_EDITING + line_input_t *line_input_state; +#endif + pid_t root_pid; + pid_t last_bg_pid; +#if ENABLE_HUSH_JOB + int run_list_level; + int last_jobid; + pid_t saved_tty_pgrp; + struct pipe *job_list; +# define G_saved_tty_pgrp (G.saved_tty_pgrp) +#else +# define G_saved_tty_pgrp 0 +#endif + smallint flag_SIGINT; +#if ENABLE_HUSH_LOOPS + smallint flag_break_continue; +#endif +#if ENABLE_HUSH_FUNCTIONS + /* 0: outside of a function (or sourced file) + * -1: inside of a function, ok to use return builtin + * 1: return is invoked, skip all till end of func + */ + smallint flag_return_in_progress; +#endif + smallint fake_mode; + smallint exiting; /* used to prevent EXIT trap recursion */ + /* These four support $?, $#, and $1 */ + smalluint last_exitcode; + /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */ + smalluint global_args_malloced; + /* how many non-NULL argv's we have. NB: $# + 1 */ + int global_argc; + char **global_argv; +#if !BB_MMU + char *argv0_for_re_execing; +#endif +#if ENABLE_HUSH_LOOPS + unsigned depth_break_continue; + unsigned depth_of_loop; +#endif + const char *ifs; + const char *cwd; + struct variable *top_var; /* = &G.shell_ver (set in main()) */ + struct variable shell_ver; +#if ENABLE_HUSH_FUNCTIONS + struct function *top_func; +#endif + /* Signal and trap handling */ +#if ENABLE_HUSH_FAST + unsigned count_SIGCHLD; + unsigned handled_SIGCHLD; + smallint we_have_children; +#endif + /* which signals have non-DFL handler (even with no traps set)? */ + unsigned non_DFL_mask; + char **traps; /* char *traps[NSIG] */ + sigset_t blocked_set; + sigset_t inherited_set; +#if HUSH_DEBUG + unsigned long memleak_value; + int debug_indent; +#endif + char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2]; }; +#define G (*ptr_to_globals) +/* Not #defining name to G.name - this quickly gets unwieldy + * (too many defines). Also, I actually prefer to see when a variable + * is global, thus "G." prefix is a useful hint */ +#define INIT_G() do { \ + SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \ +} while (0) + + +/* Function prototypes for builtins */ +static int builtin_cd(char **argv); +static int builtin_echo(char **argv); +static int builtin_eval(char **argv); +static int builtin_exec(char **argv); +static int builtin_exit(char **argv); +static int builtin_export(char **argv); +#if ENABLE_HUSH_JOB +static int builtin_fg_bg(char **argv); +static int builtin_jobs(char **argv); +#endif +#if ENABLE_HUSH_HELP +static int builtin_help(char **argv); +#endif +#if HUSH_DEBUG +static int builtin_memleak(char **argv); +#endif +static int builtin_pwd(char **argv); +static int builtin_read(char **argv); +static int builtin_set(char **argv); +static int builtin_shift(char **argv); +static int builtin_source(char **argv); +static int builtin_test(char **argv); +static int builtin_trap(char **argv); +static int builtin_true(char **argv); +static int builtin_umask(char **argv); +static int builtin_unset(char **argv); +static int builtin_wait(char **argv); +#if ENABLE_HUSH_LOOPS +static int builtin_break(char **argv); +static int builtin_continue(char **argv); +#endif +#if ENABLE_HUSH_FUNCTIONS +static int builtin_return(char **argv); +#endif -/* globals, connect us to the outside world - * the first three support $?, $#, and $1 */ -char **global_argv; -unsigned int global_argc; -unsigned int last_return_code; -extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */ - -/* "globals" within this file */ -static char *ifs; -static char map[256]; -static int fake_mode; -static int interactive; -static struct close_me *close_me_head; -static const char *cwd; -static struct pipe *job_list; -static unsigned int last_bg_pid; -static unsigned int last_jobid; -static unsigned int shell_terminal; -static char *PS1; -static char *PS2; -struct variables shell_ver = { "HUSH_VERSION", "0.01", 1, 1, 0 }; -struct variables *top_vars = &shell_ver; - - -#define B_CHUNK (100) -#define B_NOSPAC 1 - -typedef struct { - char *data; - int length; - int maxlen; - int quote; - int nonnull; -} o_string; -#define NULL_O_STRING {NULL,0,0,0,0} -/* used for initialization: - o_string foo = NULL_O_STRING; */ +/* Table of built-in functions. They can be forked or not, depending on + * context: within pipes, they fork. As simple commands, they do not. + * When used in non-forking context, they can change global variables + * in the parent shell process. If forked, of course they cannot. + * For example, 'unset foo | whatever' will parse and run, but foo will + * still be set at the end. */ +struct built_in_command { + const char *cmd; + int (*function)(char **argv); +#if ENABLE_HUSH_HELP + const char *descr; +#define BLTIN(cmd, func, help) { cmd, func, help } +#else +#define BLTIN(cmd, func, help) { cmd, func } +#endif +}; -/* I can almost use ordinary FILE *. Is open_memstream() universally - * available? Where is it documented? */ -struct in_str { - const char *p; - char peek_buf[2]; - int __promptme; - int promptmode; - FILE *file; - int (*get) (struct in_str *); - int (*peek) (struct in_str *); +/* For now, echo and test are unconditionally enabled. + * Maybe make it configurable? */ +static const struct built_in_command bltins[] = { + BLTIN("." , builtin_source , "Run commands in a file"), + BLTIN(":" , builtin_true , "No-op"), + BLTIN("[" , builtin_test , "Test condition"), +#if ENABLE_HUSH_JOB + BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"), +#endif +#if ENABLE_HUSH_LOOPS + BLTIN("break" , builtin_break , "Exit from a loop"), +#endif + BLTIN("cd" , builtin_cd , "Change directory"), +#if ENABLE_HUSH_LOOPS + BLTIN("continue", builtin_continue, "Start new loop iteration"), +#endif + BLTIN("echo" , builtin_echo , "Write to stdout"), + BLTIN("eval" , builtin_eval , "Construct and run shell command"), + BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"), + BLTIN("exit" , builtin_exit , "Exit"), + BLTIN("export" , builtin_export , "Set environment variable"), +#if ENABLE_HUSH_JOB + BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"), +#endif +#if ENABLE_HUSH_HELP + BLTIN("help" , builtin_help , "List shell built-in commands"), +#endif +#if ENABLE_HUSH_JOB + BLTIN("jobs" , builtin_jobs , "List active jobs"), +#endif +#if HUSH_DEBUG + BLTIN("memleak" , builtin_memleak , "Debug tool"), +#endif + BLTIN("pwd" , builtin_pwd , "Print current directory"), + BLTIN("read" , builtin_read , "Input environment variable"), +#if ENABLE_HUSH_FUNCTIONS + BLTIN("return" , builtin_return , "Return from a function"), +#endif + BLTIN("set" , builtin_set , "Set/unset shell local variables"), + BLTIN("shift" , builtin_shift , "Shift positional parameters"), + BLTIN("test" , builtin_test , "Test condition"), + BLTIN("trap" , builtin_trap , "Trap signals"), +// BLTIN("ulimit" , builtin_return , "Control resource limits"), + BLTIN("umask" , builtin_umask , "Set file creation mask"), + BLTIN("unset" , builtin_unset , "Unset environment variable"), + BLTIN("wait" , builtin_wait , "Wait for process"), }; -#define b_getch(input) ((input)->get(input)) -#define b_peek(input) ((input)->peek(input)) -#define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n" -struct built_in_command { - char *cmd; /* name */ - char *descr; /* description */ - int (*function) (struct child_prog *); /* function ptr */ -}; +/* Debug printouts. + */ +#if HUSH_DEBUG +/* prevent disasters with G.debug_indent < 0 */ +# define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "") +# define debug_enter() (G.debug_indent++) +# define debug_leave() (G.debug_indent--) +#else +# define indent() ((void)0) +# define debug_enter() ((void)0) +# define debug_leave() ((void)0) +#endif -/* belongs in busybox.h */ -static inline int max(int a, int b) { - return (a>b)?a:b; -} +#ifndef debug_printf +# define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__)) +#endif + +#ifndef debug_printf_parse +# define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__)) +#endif + +#ifndef debug_printf_exec +#define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__)) +#endif + +#ifndef debug_printf_env +# define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__)) +#endif -/* This should be in utility.c */ -#ifdef DEBUG_SHELL -static void debug_printf(const char *format, ...) +#ifndef debug_printf_jobs +# define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__)) +# define DEBUG_JOBS 1 +#else +# define DEBUG_JOBS 0 +#endif + +#ifndef debug_printf_expand +# define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__)) +# define DEBUG_EXPAND 1 +#else +# define DEBUG_EXPAND 0 +#endif + +#ifndef debug_printf_glob +# define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__)) +# define DEBUG_GLOB 1 +#else +# define DEBUG_GLOB 0 +#endif + +#ifndef debug_printf_list +# define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__)) +#endif + +#ifndef debug_printf_subst +# define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__)) +#endif + +#ifndef debug_printf_clean +# define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__)) +# define DEBUG_CLEAN 1 +#else +# define DEBUG_CLEAN 0 +#endif + +#if DEBUG_EXPAND +static void debug_print_strings(const char *prefix, char **vv) { - va_list args; - va_start(args, format); - vfprintf(stderr, format, args); - va_end(args); + indent(); + fprintf(stderr, "%s:\n", prefix); + while (*vv) + fprintf(stderr, " '%s'\n", *vv++); } #else -static inline void debug_printf(const char *format, ...) { } -#endif -#define final_printf debug_printf - -static void __syntax(char *file, int line) { - bb_error_msg("syntax error %s:%d", file, line); -} -#define syntax() __syntax(__FILE__, __LINE__) - -/* Index of subroutines: */ -/* function prototypes for builtins */ -static int builtin_cd(struct child_prog *child); -static int builtin_env(struct child_prog *child); -static int builtin_eval(struct child_prog *child); -static int builtin_exec(struct child_prog *child); -static int builtin_exit(struct child_prog *child); -static int builtin_export(struct child_prog *child); -static int builtin_fg_bg(struct child_prog *child); -static int builtin_help(struct child_prog *child); -static int builtin_jobs(struct child_prog *child); -static int builtin_pwd(struct child_prog *child); -static int builtin_read(struct child_prog *child); -static int builtin_set(struct child_prog *child); -static int builtin_shift(struct child_prog *child); -static int builtin_source(struct child_prog *child); -static int builtin_umask(struct child_prog *child); -static int builtin_unset(struct child_prog *child); -static int builtin_not_written(struct child_prog *child); -/* o_string manipulation: */ -static int b_check_space(o_string *o, int len); -static int b_addchr(o_string *o, int ch); -static void b_reset(o_string *o); -static int b_addqchr(o_string *o, int ch, int quote); -static int b_adduint(o_string *o, unsigned int i); -/* in_str manipulations: */ -static int static_get(struct in_str *i); -static int static_peek(struct in_str *i); -static int file_get(struct in_str *i); -static int file_peek(struct in_str *i); -static void setup_file_in_str(struct in_str *i, FILE *f); -static void setup_string_in_str(struct in_str *i, const char *s); -/* close_me manipulations: */ -static void mark_open(int fd); -static void mark_closed(int fd); -static void close_all(void); -/* "run" the final data structures: */ -static char *indenter(int i); -static int free_pipe_list(struct pipe *head, int indent); -static int free_pipe(struct pipe *pi, int indent); -/* really run the final data structures: */ -static int setup_redirects(struct child_prog *prog, int squirrel[]); -static int run_list_real(struct pipe *pi); -static void pseudo_exec(struct child_prog *child) __attribute__ ((noreturn)); -static int run_pipe_real(struct pipe *pi); -/* extended glob support: */ -static int globhack(const char *src, int flags, glob_t *pglob); -static int glob_needed(const char *s); -static int xglob(o_string *dest, int flags, glob_t *pglob); -/* variable assignment: */ -static int is_assignment(const char *s); -/* data structure manipulation: */ -static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input); -static void initialize_context(struct p_context *ctx); -static int done_word(o_string *dest, struct p_context *ctx); -static int done_command(struct p_context *ctx); -static int done_pipe(struct p_context *ctx, pipe_style type); -/* primary string parsing: */ -static int redirect_dup_num(struct in_str *input); -static int redirect_opt_num(o_string *o); -static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end); -static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch); -static char *lookup_param(char *src); -static char *make_string(char **inp); -static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input); -static int parse_string(o_string *dest, struct p_context *ctx, const char *src); -static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger); -/* setup: */ -static int parse_stream_outer(struct in_str *inp, int flag); -static int parse_string_outer(const char *s, int flag); -static int parse_file_outer(FILE *f); -/* job management: */ -static int checkjobs(struct pipe* fg_pipe); -static void insert_bg_job(struct pipe *pi); -static void remove_bg_job(struct pipe *pi); -/* local variable support */ -static char **make_list_in(char **inp, char *name); -static char *insert_var_value(char *inp); -static char *get_local_var(const char *var); -static void unset_local_var(const char *name); -static int set_local_var(const char *s, int flg_export); +#define debug_print_strings(prefix, vv) ((void)0) +#endif -/* Table of built-in functions. They can be forked or not, depending on - * context: within pipes, they fork. As simple commands, they do not. - * When used in non-forking context, they can change global variables - * in the parent shell process. If forked, of course they can not. - * For example, 'unset foo | whatever' will parse and run, but foo will - * still be set at the end. */ -static struct built_in_command bltins[] = { - {"bg", "Resume a job in the background", builtin_fg_bg}, - {"break", "Exit for, while or until loop", builtin_not_written}, - {"cd", "Change working directory", builtin_cd}, - {"continue", "Continue for, while or until loop", builtin_not_written}, - {"env", "Print all environment variables", builtin_env}, - {"eval", "Construct and run shell command", builtin_eval}, - {"exec", "Exec command, replacing this shell with the exec'd process", - builtin_exec}, - {"exit", "Exit from shell()", builtin_exit}, - {"export", "Set environment variable", builtin_export}, - {"fg", "Bring job into the foreground", builtin_fg_bg}, - {"jobs", "Lists the active jobs", builtin_jobs}, - {"pwd", "Print current directory", builtin_pwd}, - {"read", "Input environment variable", builtin_read}, - {"return", "Return from a function", builtin_not_written}, - {"set", "Set/unset shell local variables", builtin_set}, - {"shift", "Shift positional parameters", builtin_shift}, - {"trap", "Trap signals", builtin_not_written}, - {"ulimit","Controls resource limits", builtin_not_written}, - {"umask","Sets file creation mask", builtin_umask}, - {"unset", "Unset environment variable", builtin_unset}, - {".", "Source-in and run commands in a file", builtin_source}, - {"help", "List shell built-in commands", builtin_help}, - {NULL, NULL, NULL} -}; -static const char *set_cwd(void) +/* Leak hunting. Use hush_leaktool.sh for post-processing. + */ +#if LEAK_HUNTING +static void *xxmalloc(int lineno, size_t size) +{ + void *ptr = xmalloc((size + 0xff) & ~0xff); + fdprintf(2, "line %d: malloc %p\n", lineno, ptr); + return ptr; +} +static void *xxrealloc(int lineno, void *ptr, size_t size) +{ + ptr = xrealloc(ptr, (size + 0xff) & ~0xff); + fdprintf(2, "line %d: realloc %p\n", lineno, ptr); + return ptr; +} +static char *xxstrdup(int lineno, const char *str) { - if(cwd==bb_msg_unknown) - cwd = NULL; /* xgetcwd(arg) called free(arg) */ - cwd = xgetcwd((char *)cwd); - if (!cwd) - cwd = bb_msg_unknown; - return cwd; + char *ptr = xstrdup(str); + fdprintf(2, "line %d: strdup %p\n", lineno, ptr); + return ptr; } +static void xxfree(void *ptr) +{ + fdprintf(2, "free %p\n", ptr); + free(ptr); +} +#define xmalloc(s) xxmalloc(__LINE__, s) +#define xrealloc(p, s) xxrealloc(__LINE__, p, s) +#define xstrdup(s) xxstrdup(__LINE__, s) +#define free(p) xxfree(p) +#endif + -/* built-in 'eval' handler */ -static int builtin_eval(struct child_prog *child) +/* Syntax and runtime errors. They always abort scripts. + * In interactive use they usually discard unparsed and/or unexecuted commands + * and return to the prompt. + * HUSH_DEBUG >= 2 prints line number in this file where it was detected. + */ +#if HUSH_DEBUG < 2 +# define die_if_script(lineno, fmt...) die_if_script(fmt) +# define syntax_error(lineno, msg) syntax_error(msg) +# define syntax_error_at(lineno, msg) syntax_error_at(msg) +# define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch) +# define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s) +# define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch) +#endif + +static void die_if_script(unsigned lineno, const char *fmt, ...) { - char *str = NULL; - int rcode = EXIT_SUCCESS; - - if (child->argv[1]) { - str = make_string(child->argv + 1); - parse_string_outer(str, FLAG_EXIT_FROM_LOOP | - FLAG_PARSE_SEMICOLON); - free(str); - rcode = last_return_code; - } - return rcode; + va_list p; + +#if HUSH_DEBUG >= 2 + bb_error_msg("hush.c:%u", lineno); +#endif + va_start(p, fmt); + bb_verror_msg(fmt, p, NULL); + va_end(p); + if (!G_interactive_fd) + xfunc_die(); } -/* built-in 'cd <path>' handler */ -static int builtin_cd(struct child_prog *child) +static void syntax_error(unsigned lineno, const char *msg) { - char *newdir; - if (child->argv[1] == NULL) - newdir = getenv("HOME"); + if (msg) + die_if_script(lineno, "syntax error: %s", msg); else - newdir = child->argv[1]; - if (chdir(newdir)) { - printf("cd: %s: %s\n", newdir, strerror(errno)); - return EXIT_FAILURE; - } - set_cwd(); - return EXIT_SUCCESS; + die_if_script(lineno, "syntax error", NULL); } -/* built-in 'env' handler */ -static int builtin_env(struct child_prog *dummy) +static void syntax_error_at(unsigned lineno, const char *msg) { - char **e = environ; - if (e == NULL) return EXIT_FAILURE; - for (; *e; e++) { - puts(*e); - } - return EXIT_SUCCESS; + die_if_script(lineno, "syntax error at '%s'", msg); } -/* built-in 'exec' handler */ -static int builtin_exec(struct child_prog *child) +/* It so happens that all such cases are totally fatal + * even if shell is interactive: EOF while looking for closing + * delimiter. There is nowhere to read stuff from after that, + * it's EOF! The only choice is to terminate. + */ +static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN; +static void syntax_error_unterm_ch(unsigned lineno, char ch) { - if (child->argv[1] == NULL) - return EXIT_SUCCESS; /* Really? */ - child->argv++; - pseudo_exec(child); - /* never returns */ + char msg[2]; + msg[0] = ch; + msg[1] = '\0'; + die_if_script(lineno, "syntax error: unterminated %s", msg); + xfunc_die(); } -/* built-in 'exit' handler */ -static int builtin_exit(struct child_prog *child) +static void syntax_error_unterm_str(unsigned lineno, const char *s) { - if (child->argv[1] == NULL) - exit(last_return_code); - exit (atoi(child->argv[1])); + die_if_script(lineno, "syntax error: unterminated %s", s); } -/* built-in 'export VAR=value' handler */ -static int builtin_export(struct child_prog *child) +static void syntax_error_unexpected_ch(unsigned lineno, int ch) { - int res = 0; - char *name = child->argv[1]; - - if (name == NULL) { - return (builtin_env(child)); - } + char msg[2]; + msg[0] = ch; + msg[1] = '\0'; + die_if_script(lineno, "syntax error: unexpected %s", ch == EOF ? "EOF" : msg); +} - name = strdup(name); +#if HUSH_DEBUG < 2 +# undef die_if_script +# undef syntax_error +# undef syntax_error_at +# undef syntax_error_unterm_ch +# undef syntax_error_unterm_str +# undef syntax_error_unexpected_ch +#else +# define die_if_script(fmt...) die_if_script(__LINE__, fmt) +# define syntax_error(msg) syntax_error(__LINE__, msg) +# define syntax_error_at(msg) syntax_error_at(__LINE__, msg) +# define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch) +# define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s) +# define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch) +#endif - if(name) { - char *value = strchr(name, '='); - if (!value) { - char *tmp; - /* They are exporting something without an =VALUE */ +#if ENABLE_HUSH_INTERACTIVE +static void cmdedit_update_prompt(void); +#else +# define cmdedit_update_prompt() +#endif - value = get_local_var(name); - if (value) { - size_t ln = strlen(name); - tmp = realloc(name, ln+strlen(value)+2); - if(tmp==NULL) - res = -1; - else { - sprintf(tmp+ln, "=%s", value); - name = tmp; - } - } else { - /* bash does not return an error when trying to export - * an undefined variable. Do likewise. */ - res = 1; - } - } +/* Utility functions + */ +static int glob_needed(const char *s) +{ + while (*s) { + if (*s == '\\') + s++; + if (*s == '*' || *s == '[' || *s == '?') + return 1; + s++; } - if (res<0) - bb_perror_msg("export"); - else if(res==0) - res = set_local_var(name, 1); - else - res = 0; - free(name); - return res; + return 0; } -/* built-in 'fg' and 'bg' handler */ -static int builtin_fg_bg(struct child_prog *child) +static int is_well_formed_var_name(const char *s, char terminator) { - int i, jobnum; - struct pipe *pi=NULL; - - if (!interactive) - return EXIT_FAILURE; - /* If they gave us no args, assume they want the last backgrounded task */ - if (!child->argv[1]) { - for (pi = job_list; pi; pi = pi->next) { - if (pi->jobid == last_jobid) { - break; - } - } - if (!pi) { - bb_error_msg("%s: no current job", child->argv[0]); - return EXIT_FAILURE; - } - } else { - if (sscanf(child->argv[1], "%%%d", &jobnum) != 1) { - bb_error_msg("%s: bad argument '%s'", child->argv[0], child->argv[1]); - return EXIT_FAILURE; - } - for (pi = job_list; pi; pi = pi->next) { - if (pi->jobid == jobnum) { - break; - } - } - if (!pi) { - bb_error_msg("%s: %d: no such job", child->argv[0], jobnum); - return EXIT_FAILURE; - } - } + if (!s || !(isalpha(*s) || *s == '_')) + return 0; + s++; + while (isalnum(*s) || *s == '_') + s++; + return *s == terminator; +} - if (*child->argv[0] == 'f') { - /* Put the job into the foreground. */ - tcsetpgrp(shell_terminal, pi->pgrp); +/* Replace each \x with x in place, return ptr past NUL. */ +static char *unbackslash(char *src) +{ + char *dst = src; + while (1) { + if (*src == '\\') + src++; + if ((*dst++ = *src++) == '\0') + break; } + return dst; +} - /* Restart the processes in the job */ - for (i = 0; i < pi->num_progs; i++) - pi->progs[i].is_stopped = 0; - - if ( (i=kill(- pi->pgrp, SIGCONT)) < 0) { - if (i == ESRCH) { - remove_bg_job(pi); - } else { - bb_perror_msg("kill (SIGCONT)"); +static char **add_strings_to_strings(char **strings, char **add, int need_to_dup) +{ + int i; + unsigned count1; + unsigned count2; + char **v; + + v = strings; + count1 = 0; + if (v) { + while (*v) { + count1++; + v++; } } + count2 = 0; + v = add; + while (*v) { + count2++; + v++; + } + v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*)); + v[count1 + count2] = NULL; + i = count2; + while (--i >= 0) + v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]); + return v; +} +#if LEAK_HUNTING +static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup) +{ + char **ptr = add_strings_to_strings(strings, add, need_to_dup); + fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr); + return ptr; +} +#define add_strings_to_strings(strings, add, need_to_dup) \ + xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup) +#endif - pi->stopped_progs = 0; - return EXIT_SUCCESS; +/* Note: takes ownership of "add" ptr (it is not strdup'ed) */ +static char **add_string_to_strings(char **strings, char *add) +{ + char *v[2]; + v[0] = add; + v[1] = NULL; + return add_strings_to_strings(strings, v, /*dup:*/ 0); } +#if LEAK_HUNTING +static char **xx_add_string_to_strings(int lineno, char **strings, char *add) +{ + char **ptr = add_string_to_strings(strings, add); + fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr); + return ptr; +} +#define add_string_to_strings(strings, add) \ + xx_add_string_to_strings(__LINE__, strings, add) +#endif -/* built-in 'help' handler */ -static int builtin_help(struct child_prog *dummy) +static void free_strings(char **strings) { - struct built_in_command *x; + char **v; - printf("\nBuilt-in commands:\n"); - printf("-------------------\n"); - for (x = bltins; x->cmd; x++) { - if (x->descr==NULL) - continue; - printf("%s\t%s\n", x->cmd, x->descr); + if (!strings) + return; + v = strings; + while (*v) { + free(*v); + v++; } - printf("\n\n"); - return EXIT_SUCCESS; + free(strings); } -/* built-in 'jobs' handler */ -static int builtin_jobs(struct child_prog *child) + +/* Helpers for setting new $n and restoring them back + */ +typedef struct save_arg_t { + char *sv_argv0; + char **sv_g_argv; + int sv_g_argc; + smallint sv_g_malloced; +} save_arg_t; + +static void save_and_replace_G_args(save_arg_t *sv, char **argv) { - struct pipe *job; - char *status_string; + int n; - for (job = job_list; job; job = job->next) { - if (job->running_progs == job->stopped_progs) - status_string = "Stopped"; - else - status_string = "Running"; + sv->sv_argv0 = argv[0]; + sv->sv_g_argv = G.global_argv; + sv->sv_g_argc = G.global_argc; + sv->sv_g_malloced = G.global_args_malloced; - printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text); + argv[0] = G.global_argv[0]; /* retain $0 */ + G.global_argv = argv; + G.global_args_malloced = 0; + + n = 1; + while (*++argv) + n++; + G.global_argc = n; +} + +static void restore_G_args(save_arg_t *sv, char **argv) +{ + char **pp; + + if (G.global_args_malloced) { + /* someone ran "set -- arg1 arg2 ...", undo */ + pp = G.global_argv; + while (*++pp) /* note: does not free $0 */ + free(*pp); + free(G.global_argv); } - return EXIT_SUCCESS; + argv[0] = sv->sv_argv0; + G.global_argv = sv->sv_g_argv; + G.global_argc = sv->sv_g_argc; + G.global_args_malloced = sv->sv_g_malloced; } -/* built-in 'pwd' handler */ -static int builtin_pwd(struct child_prog *dummy) +/* Basic theory of signal handling in shell + * ======================================== + * This does not describe what hush does, rather, it is current understanding + * what it _should_ do. If it doesn't, it's a bug. + * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap + * + * Signals are handled only after each pipe ("cmd | cmd | cmd" thing) + * is finished or backgrounded. It is the same in interactive and + * non-interactive shells, and is the same regardless of whether + * a user trap handler is installed or a shell special one is in effect. + * ^C or ^Z from keyboard seem to execute "at once" because it usually + * backgrounds (i.e. stops) or kills all members of currently running + * pipe. + * + * Wait builtin in interruptible by signals for which user trap is set + * or by SIGINT in interactive shell. + * + * Trap handlers will execute even within trap handlers. (right?) + * + * User trap handlers are forgotten when subshell ("(cmd)") is entered. + * + * If job control is off, backgrounded commands ("cmd &") + * have SIGINT, SIGQUIT set to SIG_IGN. + * + * Commands run in command substitution ("`cmd`") + * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN. + * + * Ordinary commands have signals set to SIG_IGN/DFL set as inherited + * by the shell from its parent. + * + * Siganls which differ from SIG_DFL action + * (note: child (i.e., [v]forked) shell is not an interactive shell): + * + * SIGQUIT: ignore + * SIGTERM (interactive): ignore + * SIGHUP (interactive): + * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit + * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore + * Note that ^Z is handled not by trapping SIGTSTP, but by seeing + * that all pipe members are stopped. Try this in bash: + * while :; do :; done - ^Z does not background it + * (while :; do :; done) - ^Z backgrounds it + * SIGINT (interactive): wait for last pipe, ignore the rest + * of the command line, show prompt. NB: ^C does not send SIGINT + * to interactive shell while shell is waiting for a pipe, + * since shell is bg'ed (is not in foreground process group). + * Example 1: this waits 5 sec, but does not execute ls: + * "echo $$; sleep 5; ls -l" + "kill -INT <pid>" + * Example 2: this does not wait and does not execute ls: + * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>" + * Example 3: this does not wait 5 sec, but executes ls: + * "sleep 5; ls -l" + press ^C + * + * (What happens to signals which are IGN on shell start?) + * (What happens with signal mask on shell start?) + * + * Implementation in hush + * ====================== + * We use in-kernel pending signal mask to determine which signals were sent. + * We block all signals which we don't want to take action immediately, + * i.e. we block all signals which need to have special handling as described + * above, and all signals which have traps set. + * After each pipe execution, we extract any pending signals via sigtimedwait() + * and act on them. + * + * unsigned non_DFL_mask: a mask of such "special" signals + * sigset_t blocked_set: current blocked signal set + * + * "trap - SIGxxx": + * clear bit in blocked_set unless it is also in non_DFL_mask + * "trap 'cmd' SIGxxx": + * set bit in blocked_set (even if 'cmd' is '') + * after [v]fork, if we plan to be a shell: + * unblock signals with special interactive handling + * (child shell is not interactive), + * unset all traps (note: regardless of child shell's type - {}, (), etc) + * after [v]fork, if we plan to exec: + * POSIX says pending signal mask is cleared in child - no need to clear it. + * Restore blocked signal set to one inherited by shell just prior to exec. + * + * Note: as a result, we do not use signal handlers much. The only uses + * are to count SIGCHLDs + * and to restore tty pgrp on signal-induced exit. + */ +enum { + SPECIAL_INTERACTIVE_SIGS = 0 + | (1 << SIGTERM) + | (1 << SIGINT) + | (1 << SIGHUP) + , + SPECIAL_JOB_SIGS = 0 +#if ENABLE_HUSH_JOB + | (1 << SIGTTIN) + | (1 << SIGTTOU) + | (1 << SIGTSTP) +#endif +}; + +#if ENABLE_HUSH_FAST +static void SIGCHLD_handler(int sig UNUSED_PARAM) { - puts(set_cwd()); - return EXIT_SUCCESS; + G.count_SIGCHLD++; +//bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD); } +#endif + +#if ENABLE_HUSH_JOB -/* built-in 'read VAR' handler */ -static int builtin_read(struct child_prog *child) +/* After [v]fork, in child: do not restore tty pgrp on xfunc death */ +#define disable_restore_tty_pgrp_on_exit() (die_sleep = 0) +/* After [v]fork, in parent: restore tty pgrp on xfunc death */ +#define enable_restore_tty_pgrp_on_exit() (die_sleep = -1) + +/* Restores tty foreground process group, and exits. + * May be called as signal handler for fatal signal + * (will resend signal to itself, producing correct exit state) + * or called directly with -EXITCODE. + * We also call it if xfunc is exiting. */ +static void sigexit(int sig) NORETURN; +static void sigexit(int sig) { - int res; + /* Disable all signals: job control, SIGPIPE, etc. */ + sigprocmask_allsigs(SIG_BLOCK); - if (child->argv[1]) { - char string[BUFSIZ]; - char *var = 0; + /* Careful: we can end up here after [v]fork. Do not restore + * tty pgrp then, only top-level shell process does that */ + if (G_saved_tty_pgrp && getpid() == G.root_pid) + tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp); - string[0] = 0; /* In case stdin has only EOF */ - /* read string */ - fgets(string, sizeof(string), stdin); - chomp(string); - var = malloc(strlen(child->argv[1])+strlen(string)+2); - if(var) { - sprintf(var, "%s=%s", child->argv[1], string); - res = set_local_var(var, 0); - } else - res = -1; - if (res) - fprintf(stderr, "read: %m\n"); - free(var); /* So not move up to avoid breaking errno */ - return res; - } else { - do res=getchar(); while(res!='\n' && res!=EOF); - return 0; + /* Not a signal, just exit */ + if (sig <= 0) + _exit(- sig); + + kill_myself_with_sig(sig); /* does not return */ +} +#else + +#define disable_restore_tty_pgrp_on_exit() ((void)0) +#define enable_restore_tty_pgrp_on_exit() ((void)0) + +#endif + +/* Restores tty foreground process group, and exits. */ +static void hush_exit(int exitcode) NORETURN; +static void hush_exit(int exitcode) +{ + if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) { + /* Prevent recursion: + * trap "echo Hi; exit" EXIT; exit + */ + char *argv[] = { NULL, G.traps[0], NULL }; + G.traps[0] = NULL; + G.exiting = 1; + builtin_eval(argv); + free(argv[1]); } + +#if ENABLE_HUSH_JOB + fflush(NULL); /* flush all streams */ + sigexit(- (exitcode & 0xff)); +#else + exit(exitcode); +#endif } -/* built-in 'set VAR=value' handler */ -static int builtin_set(struct child_prog *child) +static int check_and_run_traps(int sig) { - char *temp = child->argv[1]; - struct variables *e; + static const struct timespec zero_timespec = { 0, 0 }; + smalluint save_rcode; + int last_sig = 0; + + if (sig) + goto jump_in; + while (1) { + sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec); + if (sig <= 0) + break; + jump_in: + last_sig = sig; + if (G.traps && G.traps[sig]) { + if (G.traps[sig][0]) { + /* We have user-defined handler */ + char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL }; + save_rcode = G.last_exitcode; + builtin_eval(argv); + free(argv[1]); + G.last_exitcode = save_rcode; + } /* else: "" trap, ignoring signal */ + continue; + } + /* not a trap: special action */ + switch (sig) { +#if ENABLE_HUSH_FAST + case SIGCHLD: + G.count_SIGCHLD++; +//bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD); + break; +#endif + case SIGINT: + /* Builtin was ^C'ed, make it look prettier: */ + bb_putchar('\n'); + G.flag_SIGINT = 1; + break; +#if ENABLE_HUSH_JOB + case SIGHUP: { + struct pipe *job; + /* bash is observed to signal whole process groups, + * not individual processes */ + for (job = G.job_list; job; job = job->next) { + if (job->pgrp <= 0) + continue; + debug_printf_exec("HUPing pgrp %d\n", job->pgrp); + if (kill(- job->pgrp, SIGHUP) == 0) + kill(- job->pgrp, SIGCONT); + } + sigexit(SIGHUP); + } +#endif + default: /* ignored: */ + /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */ + break; + } + } + return last_sig; +} - if (temp == NULL) - for(e = top_vars; e; e=e->next) - printf("%s=%s\n", e->name, e->value); - else - set_local_var(temp, 0); - return EXIT_SUCCESS; +static const char *set_cwd(void) +{ + /* xrealloc_getcwd_or_warn(arg) calls free(arg), + * we must not try to free(bb_msg_unknown) */ + if (G.cwd == bb_msg_unknown) + G.cwd = NULL; + G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd); + if (!G.cwd) + G.cwd = bb_msg_unknown; + return G.cwd; } -/* Built-in 'shift' handler */ -static int builtin_shift(struct child_prog *child) +/* + * Shell and environment variable support + */ +static struct variable **get_ptr_to_local_var(const char *name) { - int n=1; - if (child->argv[1]) { - n=atoi(child->argv[1]); - } - if (n>=0 && n<global_argc) { - /* XXX This probably breaks $0 */ - global_argc -= n; - global_argv += n; - return EXIT_SUCCESS; - } else { - return EXIT_FAILURE; + struct variable **pp; + struct variable *cur; + int len; + + len = strlen(name); + pp = &G.top_var; + while ((cur = *pp) != NULL) { + if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=') + return pp; + pp = &cur->next; } + return NULL; } -/* Built-in '.' handler (read-in and execute commands from file) */ -static int builtin_source(struct child_prog *child) +static struct variable *get_local_var(const char *name) { - FILE *input; - int status; + struct variable **pp = get_ptr_to_local_var(name); + if (pp) + return *pp; + return NULL; +} - if (child->argv[1] == NULL) - return EXIT_FAILURE; +static const char *get_local_var_value(const char *name) +{ + struct variable **pp = get_ptr_to_local_var(name); + if (pp) + return strchr((*pp)->varstr, '=') + 1; + return NULL; +} - /* XXX search through $PATH is missing */ - input = fopen(child->argv[1], "r"); - if (!input) { - bb_error_msg("Couldn't open file '%s'", child->argv[1]); - return EXIT_FAILURE; +/* str holds "NAME=VAL" and is expected to be malloced. + * We take ownership of it. + * flg_export: + * 0: do not change export flag + * (if creating new variable, flag will be 0) + * 1: set export flag and putenv the variable + * -1: clear export flag and unsetenv the variable + * flg_read_only is set only when we handle -R var=val + */ +#if BB_MMU +#define set_local_var(str, flg_export, flg_read_only) \ + set_local_var(str, flg_export) +#endif +static int set_local_var(char *str, int flg_export, int flg_read_only) +{ + struct variable *cur; + char *eq_sign; + int name_len; + + eq_sign = strchr(str, '='); + if (!eq_sign) { /* not expected to ever happen? */ + free(str); + return -1; } - /* Now run the file */ - /* XXX argv and argc are broken; need to save old global_argv - * (pointer only is OK!) on this stack frame, - * set global_argv=child->argv+1, recurse, and restore. */ - mark_open(fileno(input)); - status = parse_file_outer(input); - mark_closed(fileno(input)); - fclose(input); - return (status); -} + name_len = eq_sign - str + 1; /* including '=' */ + cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */ + while (1) { + if (strncmp(cur->varstr, str, name_len) != 0) { + if (!cur->next) { + /* Bail out. Note that now cur points + * to last var in linked list */ + break; + } + cur = cur->next; + continue; + } + /* We found an existing var with this name */ + if (cur->flg_read_only) { +#if !BB_MMU + if (!flg_read_only) +#endif + bb_error_msg("%s: readonly variable", str); + free(str); + return -1; + } + if (flg_export == -1) { + debug_printf_env("%s: unsetenv '%s'\n", __func__, str); + *eq_sign = '\0'; + unsetenv(str); + *eq_sign = '='; + } + if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) { + free_and_exp: + free(str); + goto exp; + } + if (cur->max_len >= strlen(str)) { + /* This one is from startup env, reuse space */ + strcpy(cur->varstr, str); + goto free_and_exp; + } + /* max_len == 0 signifies "malloced" var, which we can + * (and has to) free */ + if (!cur->max_len) + free(cur->varstr); + cur->max_len = 0; + goto set_str_and_exp; + } -static int builtin_umask(struct child_prog *child) -{ - mode_t new_umask; - const char *arg = child->argv[1]; - char *end; - if (arg) { - new_umask=strtoul(arg, &end, 8); - if (*end!='\0' || end == arg) { - return EXIT_FAILURE; + /* Not found - create next variable struct */ + cur->next = xzalloc(sizeof(*cur)); + cur = cur->next; + + set_str_and_exp: + cur->varstr = str; +#if !BB_MMU + cur->flg_read_only = flg_read_only; +#endif + exp: + if (flg_export == 1) + cur->flg_export = 1; + if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S') + cmdedit_update_prompt(); + if (cur->flg_export) { + if (flg_export == -1) { + cur->flg_export = 0; + /* unsetenv was already done */ + } else { + debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr); + return putenv(cur->varstr); } - } else { - printf("%.3o\n", (unsigned int) (new_umask=umask(0))); } - umask(new_umask); - return EXIT_SUCCESS; + return 0; } -/* built-in 'unset VAR' handler */ -static int builtin_unset(struct child_prog *child) +static int unset_local_var_len(const char *name, int name_len) { - /* bash returned already true */ - unset_local_var(child->argv[1]); + struct variable *cur; + struct variable **var_pp; + + if (!name) + return EXIT_SUCCESS; + var_pp = &G.top_var; + while ((cur = *var_pp) != NULL) { + if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') { + if (cur->flg_read_only) { + bb_error_msg("%s: readonly variable", name); + return EXIT_FAILURE; + } + *var_pp = cur->next; + debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr); + bb_unsetenv(cur->varstr); + if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S') + cmdedit_update_prompt(); + if (!cur->max_len) + free(cur->varstr); + free(cur); + return EXIT_SUCCESS; + } + var_pp = &cur->next; + } return EXIT_SUCCESS; } -static int builtin_not_written(struct child_prog *child) +static int unset_local_var(const char *name) { - printf("builtin_%s not written\n",child->argv[0]); - return EXIT_FAILURE; + return unset_local_var_len(name, strlen(name)); } -static int b_check_space(o_string *o, int len) +static void unset_vars(char **strings) { - /* It would be easy to drop a more restrictive policy - * in here, such as setting a maximum string length */ - if (o->length + len > o->maxlen) { - char *old_data = o->data; - /* assert (data == NULL || o->maxlen != 0); */ - o->maxlen += max(2*len, B_CHUNK); - o->data = realloc(o->data, 1 + o->maxlen); - if (o->data == NULL) { - free(old_data); - } + char **v; + + if (!strings) + return; + v = strings; + while (*v) { + const char *eq = strchrnul(*v, '='); + unset_local_var_len(*v, (int)(eq - *v)); + v++; } - return o->data == NULL; + free(strings); } -static int b_addchr(o_string *o, int ch) +#if ENABLE_SH_MATH_SUPPORT +#define is_name(c) ((c) == '_' || isalpha((unsigned char)(c))) +#define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c))) +static char *endofname(const char *name) { - debug_printf("b_addchr: %c %d %p\n", ch, o->length, o); - if (b_check_space(o, 1)) return B_NOSPAC; - o->data[o->length] = ch; - o->length++; - o->data[o->length] = '\0'; - return 0; -} + char *p; -static void b_reset(o_string *o) -{ - o->length = 0; - o->nonnull = 0; - if (o->data != NULL) *o->data = '\0'; + p = (char *) name; + if (!is_name(*p)) + return p; + while (*++p) { + if (!is_in_name(*p)) + break; + } + return p; } -static void b_free(o_string *o) +static void arith_set_local_var(const char *name, const char *val, int flags) { - b_reset(o); - free(o->data); - o->data = NULL; - o->maxlen = 0; + /* arith code doesnt malloc space, so do it for it */ + char *var = xasprintf("%s=%s", name, val); + set_local_var(var, flags, 0); } +#endif -/* My analysis of quoting semantics tells me that state information - * is associated with a destination, not a source. + +/* + * Helpers for "var1=val1 var2=val2 cmd" feature */ -static int b_addqchr(o_string *o, int ch, int quote) +static void add_vars(struct variable *var) { - if (quote && strchr("*?[\\",ch)) { - int rc; - rc = b_addchr(o, '\\'); - if (rc) return rc; + struct variable *next; + + while (var) { + next = var->next; + var->next = G.top_var; + G.top_var = var; + if (var->flg_export) { + debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr); + putenv(var->varstr); + } else { + debug_printf_env("%s: restoring local '%s'\n", __func__, var->varstr); + } + var = next; } - return b_addchr(o, ch); } -/* belongs in utility.c */ -char *simple_itoa(unsigned int i) +static struct variable *set_vars_and_save_old(char **strings) { - /* 21 digits plus null terminator, good for 64-bit or smaller ints */ - static char local[22]; - char *p = &local[21]; - *p-- = '\0'; - do { - *p-- = '0' + i % 10; - i /= 10; - } while (i > 0); - return p + 1; + char **s; + struct variable *old = NULL; + + if (!strings) + return old; + s = strings; + while (*s) { + struct variable *var_p; + struct variable **var_pp; + char *eq; + + eq = strchr(*s, '='); + if (eq) { + *eq = '\0'; + var_pp = get_ptr_to_local_var(*s); + *eq = '='; + if (var_pp) { + /* Remove variable from global linked list */ + var_p = *var_pp; + debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr); + *var_pp = var_p->next; + /* Add it to returned list */ + var_p->next = old; + old = var_p; + } + set_local_var(*s, 1, 0); + } + s++; + } + return old; } -static int b_adduint(o_string *o, unsigned int i) -{ - int r; - char *p = simple_itoa(i); - /* no escape checking necessary */ - do r=b_addchr(o, *p++); while (r==0 && *p); - return r; -} +/* + * in_str support + */ static int static_get(struct in_str *i) { - int ch=*i->p++; - if (ch=='\0') return EOF; - return ch; + int ch = *i->p++; + if (ch != '\0') + return ch; + i->p--; + return EOF; } static int static_peek(struct in_str *i) @@ -865,114 +1496,145 @@ static int static_peek(struct in_str *i) return *i->p; } -static inline void cmdedit_set_initial_prompt(void) +#if ENABLE_HUSH_INTERACTIVE + +static void cmdedit_update_prompt(void) { -#ifndef CONFIG_FEATURE_SH_FANCY_PROMPT - PS1 = NULL; -#else - PS1 = getenv("PS1"); - if(PS1==0) - PS1 = "\\w \\$ "; -#endif -} - -static inline void setup_prompt_string(int promptmode, char **prompt_str) -{ - debug_printf("setup_prompt_string %d ",promptmode); -#ifndef CONFIG_FEATURE_SH_FANCY_PROMPT - /* Set up the prompt */ - if (promptmode == 1) { - free(PS1); - PS1=xmalloc(strlen(cwd)+4); - sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ? "$ ":"# "); - *prompt_str = PS1; + if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) { + G.PS1 = get_local_var_value("PS1"); + if (G.PS1 == NULL) + G.PS1 = "\\w \\$ "; + G.PS2 = get_local_var_value("PS2"); } else { - *prompt_str = PS2; + G.PS1 = NULL; } -#else - *prompt_str = (promptmode==1)? PS1 : PS2; -#endif - debug_printf("result %s\n",*prompt_str); + if (G.PS2 == NULL) + G.PS2 = "> "; +} + +static const char* setup_prompt_string(int promptmode) +{ + const char *prompt_str; + debug_printf("setup_prompt_string %d ", promptmode); + if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) { + /* Set up the prompt */ + if (promptmode == 0) { /* PS1 */ + free((char*)G.PS1); + G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#'); + prompt_str = G.PS1; + } else + prompt_str = G.PS2; + } else + prompt_str = (promptmode == 0) ? G.PS1 : G.PS2; + debug_printf("result '%s'\n", prompt_str); + return prompt_str; } static void get_user_input(struct in_str *i) { - char *prompt_str; - static char the_command[BUFSIZ]; + int r; + const char *prompt_str; - setup_prompt_string(i->promptmode, &prompt_str); -#ifdef CONFIG_FEATURE_COMMAND_EDITING - /* - ** enable command line editing only while a command line - ** is actually being read; otherwise, we'll end up bequeathing - ** atexit() handlers and other unwanted stuff to our - ** child processes (rob@sysgo.de) - */ - cmdedit_read_input(prompt_str, the_command); + prompt_str = setup_prompt_string(i->promptmode); +#if ENABLE_FEATURE_EDITING + /* Enable command line editing only while a command line + * is actually being read */ + do { + G.flag_SIGINT = 0; + /* buglet: SIGINT will not make new prompt to appear _at once_, + * only after <Enter>. (^C will work) */ + r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state); + /* catch *SIGINT* etc (^C is handled by read_line_input) */ + check_and_run_traps(0); + } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */ + i->eof_flag = (r < 0); + if (i->eof_flag) { /* EOF/error detected */ + G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */ + G.user_input_buf[1] = '\0'; + } #else - fputs(prompt_str, stdout); - fflush(stdout); - the_command[0]=fgetc(i->file); - the_command[1]='\0'; + do { + G.flag_SIGINT = 0; + fputs(prompt_str, stdout); + fflush(stdout); + G.user_input_buf[0] = r = fgetc(i->file); + /*G.user_input_buf[1] = '\0'; - already is and never changed */ +//do we need check_and_run_traps(0)? (maybe only if stdin) + } while (G.flag_SIGINT); + i->eof_flag = (r == EOF); #endif - fflush(stdout); - i->p = the_command; + i->p = G.user_input_buf; } -/* This is the magic location that prints prompts +#endif /* INTERACTIVE */ + +/* This is the magic location that prints prompts * and gets data back from the user */ static int file_get(struct in_str *i) { int ch; - ch = 0; /* If there is data waiting, eat it up */ if (i->p && *i->p) { - ch=*i->p++; +#if ENABLE_HUSH_INTERACTIVE + take_cached: +#endif + ch = *i->p++; + if (i->eof_flag && !*i->p) + ch = EOF; + /* note: ch is never NUL */ } else { /* need to double check i->file because we might be doing something * more complicated by now, like sourcing or substituting. */ - if (i->__promptme && interactive && i->file == stdin) { - while(! i->p || (interactive && strlen(i->p)==0) ) { +#if ENABLE_HUSH_INTERACTIVE + if (G_interactive_fd && i->promptme && i->file == stdin) { + do { get_user_input(i); - } - i->promptmode=2; - i->__promptme = 0; - if (i->p && *i->p) { - ch=*i->p++; - } - } else { - ch = fgetc(i->file); + } while (!*i->p); /* need non-empty line */ + i->promptmode = 1; /* PS2 */ + i->promptme = 0; + goto take_cached; } - - debug_printf("b_getch: got a %d\n", ch); +#endif + do ch = fgetc(i->file); while (ch == '\0'); } - if (ch == '\n') i->__promptme=1; + debug_printf("file_get: got '%c' %d\n", ch, ch); +#if ENABLE_HUSH_INTERACTIVE + if (ch == '\n') + i->promptme = 1; +#endif return ch; } -/* All the callers guarantee this routine will never be - * used right after a newline, so prompting is not needed. +/* All callers guarantee this routine will never + * be used right after a newline, so prompting is not needed. */ static int file_peek(struct in_str *i) { + int ch; if (i->p && *i->p) { + if (i->eof_flag && !i->p[1]) + return EOF; return *i->p; - } else { - i->peek_buf[0] = fgetc(i->file); - i->peek_buf[1] = '\0'; - i->p = i->peek_buf; - debug_printf("b_peek: got a %d\n", *i->p); - return *i->p; + /* note: ch is never NUL */ } + do ch = fgetc(i->file); while (ch == '\0'); + i->eof_flag = (ch == EOF); + i->peek_buf[0] = ch; + i->peek_buf[1] = '\0'; + i->p = i->peek_buf; + debug_printf("file_peek: got '%c' %d\n", ch, ch); + return ch; } static void setup_file_in_str(struct in_str *i, FILE *f) { i->peek = file_peek; i->get = file_get; - i->__promptme=1; - i->promptmode=1; +#if ENABLE_HUSH_INTERACTIVE + i->promptme = 1; + i->promptmode = 0; /* PS1 */ +#endif i->file = f; i->p = NULL; } @@ -981,73 +1643,1116 @@ static void setup_string_in_str(struct in_str *i, const char *s) { i->peek = static_peek; i->get = static_get; - i->__promptme=1; - i->promptmode=1; +#if ENABLE_HUSH_INTERACTIVE + i->promptme = 1; + i->promptmode = 0; /* PS1 */ +#endif i->p = s; + i->eof_flag = 0; +} + + +/* + * o_string support + */ +#define B_CHUNK (32 * sizeof(char*)) + +static void o_reset_to_empty_unquoted(o_string *o) +{ + o->length = 0; + o->o_quoted = 0; + if (o->data) + o->data[0] = '\0'; +} + +static void o_free(o_string *o) +{ + free(o->data); + memset(o, 0, sizeof(*o)); +} + +static ALWAYS_INLINE void o_free_unsafe(o_string *o) +{ + free(o->data); +} + +static void o_grow_by(o_string *o, int len) +{ + if (o->length + len > o->maxlen) { + o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK); + o->data = xrealloc(o->data, 1 + o->maxlen); + } +} + +static void o_addchr(o_string *o, int ch) +{ + debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o); + o_grow_by(o, 1); + o->data[o->length] = ch; + o->length++; + o->data[o->length] = '\0'; +} + +static void o_addblock(o_string *o, const char *str, int len) +{ + o_grow_by(o, len); + memcpy(&o->data[o->length], str, len); + o->length += len; + o->data[o->length] = '\0'; +} + +#if !BB_MMU +static void o_addstr(o_string *o, const char *str) +{ + o_addblock(o, str, strlen(str)); +} +static void nommu_addchr(o_string *o, int ch) +{ + if (o) + o_addchr(o, ch); +} +#else +#define nommu_addchr(o, str) ((void)0) +#endif + +static void o_addstr_with_NUL(o_string *o, const char *str) +{ + o_addblock(o, str, strlen(str) + 1); +} + +static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len) +{ + while (len) { + o_addchr(o, *str); + if (*str++ == '\\' + && (*str != '*' && *str != '?' && *str != '[') + ) { + o_addchr(o, '\\'); + } + len--; + } +} + +/* My analysis of quoting semantics tells me that state information + * is associated with a destination, not a source. + */ +static void o_addqchr(o_string *o, int ch) +{ + int sz = 1; + char *found = strchr("*?[\\", ch); + if (found) + sz++; + o_grow_by(o, sz); + if (found) { + o->data[o->length] = '\\'; + o->length++; + } + o->data[o->length] = ch; + o->length++; + o->data[o->length] = '\0'; +} + +static void o_addQchr(o_string *o, int ch) +{ + int sz = 1; + if (o->o_escape && strchr("*?[\\", ch)) { + sz++; + o->data[o->length] = '\\'; + o->length++; + } + o_grow_by(o, sz); + o->data[o->length] = ch; + o->length++; + o->data[o->length] = '\0'; +} + +static void o_addQstr(o_string *o, const char *str, int len) +{ + if (!o->o_escape) { + o_addblock(o, str, len); + return; + } + while (len) { + char ch; + int sz; + int ordinary_cnt = strcspn(str, "*?[\\"); + if (ordinary_cnt > len) /* paranoia */ + ordinary_cnt = len; + o_addblock(o, str, ordinary_cnt); + if (ordinary_cnt == len) + return; + str += ordinary_cnt; + len -= ordinary_cnt + 1; /* we are processing + 1 char below */ + + ch = *str++; + sz = 1; + if (ch) { /* it is necessarily one of "*?[\\" */ + sz++; + o->data[o->length] = '\\'; + o->length++; + } + o_grow_by(o, sz); + o->data[o->length] = ch; + o->length++; + o->data[o->length] = '\0'; + } +} + +/* A special kind of o_string for $VAR and `cmd` expansion. + * It contains char* list[] at the beginning, which is grown in 16 element + * increments. Actual string data starts at the next multiple of 16 * (char*). + * list[i] contains an INDEX (int!) into this string data. + * It means that if list[] needs to grow, data needs to be moved higher up + * but list[i]'s need not be modified. + * NB: remembering how many list[i]'s you have there is crucial. + * o_finalize_list() operation post-processes this structure - calculates + * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well. + */ +#if DEBUG_EXPAND || DEBUG_GLOB +static void debug_print_list(const char *prefix, o_string *o, int n) +{ + char **list = (char**)o->data; + int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]); + int i = 0; + + indent(); + fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n", + prefix, list, n, string_start, o->length, o->maxlen); + while (i < n) { + indent(); + fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i], + o->data + (int)list[i] + string_start, + o->data + (int)list[i] + string_start); + i++; + } + if (n) { + const char *p = o->data + (int)list[n - 1] + string_start; + indent(); + fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data)); + } +} +#else +#define debug_print_list(prefix, o, n) ((void)0) +#endif + +/* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value + * in list[n] so that it points past last stored byte so far. + * It returns n+1. */ +static int o_save_ptr_helper(o_string *o, int n) +{ + char **list = (char**)o->data; + int string_start; + int string_len; + + if (!o->has_empty_slot) { + string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]); + string_len = o->length - string_start; + if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */ + debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start); + /* list[n] points to string_start, make space for 16 more pointers */ + o->maxlen += 0x10 * sizeof(list[0]); + o->data = xrealloc(o->data, o->maxlen + 1); + list = (char**)o->data; + memmove(list + n + 0x10, list + n, string_len); + o->length += 0x10 * sizeof(list[0]); + } else { + debug_printf_list("list[%d]=%d string_start=%d\n", + n, string_len, string_start); + } + } else { + /* We have empty slot at list[n], reuse without growth */ + string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */ + string_len = o->length - string_start; + debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n", + n, string_len, string_start); + o->has_empty_slot = 0; + } + list[n] = (char*)(ptrdiff_t)string_len; + return n + 1; +} + +/* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */ +static int o_get_last_ptr(o_string *o, int n) +{ + char **list = (char**)o->data; + int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]); + + return ((int)(ptrdiff_t)list[n-1]) + string_start; +} + +/* o_glob performs globbing on last list[], saving each result + * as a new list[]. */ +static int o_glob(o_string *o, int n) +{ + glob_t globdata; + int gr; + char *pattern; + + debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data); + if (!o->data) + return o_save_ptr_helper(o, n); + pattern = o->data + o_get_last_ptr(o, n); + debug_printf_glob("glob pattern '%s'\n", pattern); + if (!glob_needed(pattern)) { + literal: + o->length = unbackslash(pattern) - o->data; + debug_printf_glob("glob pattern '%s' is literal\n", pattern); + return o_save_ptr_helper(o, n); + } + + memset(&globdata, 0, sizeof(globdata)); + gr = glob(pattern, 0, NULL, &globdata); + debug_printf_glob("glob('%s'):%d\n", pattern, gr); + if (gr == GLOB_NOSPACE) + bb_error_msg_and_die("out of memory during glob"); + if (gr == GLOB_NOMATCH) { + globfree(&globdata); + goto literal; + } + if (gr != 0) { /* GLOB_ABORTED ? */ + /* TODO: testcase for bad glob pattern behavior */ + bb_error_msg("glob(3) error %d on '%s'", gr, pattern); + } + if (globdata.gl_pathv && globdata.gl_pathv[0]) { + char **argv = globdata.gl_pathv; + o->length = pattern - o->data; /* "forget" pattern */ + while (1) { + o_addstr_with_NUL(o, *argv); + n = o_save_ptr_helper(o, n); + argv++; + if (!*argv) + break; + } + } + globfree(&globdata); + if (DEBUG_GLOB) + debug_print_list("o_glob returning", o, n); + return n; +} + +/* If o->o_glob == 1, glob the string so far remembered. + * Otherwise, just finish current list[] and start new */ +static int o_save_ptr(o_string *o, int n) +{ + if (o->o_glob) { /* if globbing is requested */ + /* If o->has_empty_slot, list[n] was already globbed + * (if it was requested back then when it was filled) + * so don't do that again! */ + if (!o->has_empty_slot) + return o_glob(o, n); /* o_save_ptr_helper is inside */ + } + return o_save_ptr_helper(o, n); +} + +/* "Please convert list[n] to real char* ptrs, and NULL terminate it." */ +static char **o_finalize_list(o_string *o, int n) +{ + char **list; + int string_start; + + n = o_save_ptr(o, n); /* force growth for list[n] if necessary */ + if (DEBUG_EXPAND) + debug_print_list("finalized", o, n); + debug_printf_expand("finalized n:%d\n", n); + list = (char**)o->data; + string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]); + list[--n] = NULL; + while (n) { + n--; + list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start; + } + return list; +} + + +/* Expansion can recurse */ +#if ENABLE_HUSH_TICK +static int process_command_subs(o_string *dest, const char *s); +#endif +static char *expand_string_to_string(const char *str); +#if BB_MMU +#define parse_stream_dquoted(as_string, dest, input, dquote_end) \ + parse_stream_dquoted(dest, input, dquote_end) +#endif +static int parse_stream_dquoted(o_string *as_string, + o_string *dest, + struct in_str *input, + int dquote_end); + +/* expand_strvec_to_strvec() takes a list of strings, expands + * all variable references within and returns a pointer to + * a list of expanded strings, possibly with larger number + * of strings. (Think VAR="a b"; echo $VAR). + * This new list is allocated as a single malloc block. + * NULL-terminated list of char* pointers is at the beginning of it, + * followed by strings themself. + * Caller can deallocate entire list by single free(list). */ + +/* Store given string, finalizing the word and starting new one whenever + * we encounter IFS char(s). This is used for expanding variable values. + * End-of-string does NOT finalize word: think about 'echo -$VAR-' */ +static int expand_on_ifs(o_string *output, int n, const char *str) +{ + while (1) { + int word_len = strcspn(str, G.ifs); + if (word_len) { + if (output->o_escape || !output->o_glob) + o_addQstr(output, str, word_len); + else /* protect backslashes against globbing up :) */ + o_addblock_duplicate_backslash(output, str, word_len); + str += word_len; + } + if (!*str) /* EOL - do not finalize word */ + break; + o_addchr(output, '\0'); + debug_print_list("expand_on_ifs", output, n); + n = o_save_ptr(output, n); + str += strspn(str, G.ifs); /* skip ifs chars */ + } + debug_print_list("expand_on_ifs[1]", output, n); + return n; +} + +/* Helper to expand $((...)) and heredoc body. These act as if + * they are in double quotes, with the exception that they are not :). + * Just the rules are similar: "expand only $var and `cmd`" + * + * Returns malloced string. + * As an optimization, we return NULL if expansion is not needed. + */ +static char *expand_pseudo_dquoted(const char *str) +{ + char *exp_str; + struct in_str input; + o_string dest = NULL_O_STRING; + + if (strchr(str, '$') == NULL +#if ENABLE_HUSH_TICK + && strchr(str, '`') == NULL +#endif + ) { + return NULL; + } + + /* We need to expand. Example: + * echo $(($a + `echo 1`)) $((1 + $((2)) )) + */ + setup_string_in_str(&input, str); + parse_stream_dquoted(NULL, &dest, &input, EOF); + //bb_error_msg("'%s' -> '%s'", str, dest.data); + exp_str = expand_string_to_string(dest.data); + //bb_error_msg("'%s' -> '%s'", dest.data, exp_str); + o_free_unsafe(&dest); + return exp_str; +} + +/* Expand all variable references in given string, adding words to list[] + * at n, n+1,... positions. Return updated n (so that list[n] is next one + * to be filled). This routine is extremely tricky: has to deal with + * variables/parameters with whitespace, $* and $@, and constructs like + * 'echo -$*-'. If you play here, you must run testsuite afterwards! */ +static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask) +{ + /* or_mask is either 0 (normal case) or 0x80 - + * expansion of right-hand side of assignment == 1-element expand. + * It will also do no globbing, and thus we must not backslash-quote! + */ + char ored_ch; + char *p; + + ored_ch = 0; + + debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg); + debug_print_list("expand_vars_to_list", output, n); + n = o_save_ptr(output, n); + debug_print_list("expand_vars_to_list[0]", output, n); + + while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) { + char first_ch; + int i; + char *dyn_val = NULL; + const char *val = NULL; +#if ENABLE_HUSH_TICK + o_string subst_result = NULL_O_STRING; +#endif +#if ENABLE_SH_MATH_SUPPORT + char arith_buf[sizeof(arith_t)*3 + 2]; +#endif + o_addblock(output, arg, p - arg); + debug_print_list("expand_vars_to_list[1]", output, n); + arg = ++p; + p = strchr(p, SPECIAL_VAR_SYMBOL); + + first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */ + /* "$@" is special. Even if quoted, it can still + * expand to nothing (not even an empty string) */ + if ((first_ch & 0x7f) != '@') + ored_ch |= first_ch; + + switch (first_ch & 0x7f) { + /* Highest bit in first_ch indicates that var is double-quoted */ + case '$': /* pid */ + val = utoa(G.root_pid); + break; + case '!': /* bg pid */ + val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)""; + break; + case '?': /* exitcode */ + val = utoa(G.last_exitcode); + break; + case '#': /* argc */ + if (arg[1] != SPECIAL_VAR_SYMBOL) + /* actually, it's a ${#var} */ + goto case_default; + val = utoa(G.global_argc ? G.global_argc-1 : 0); + break; + case '*': + case '@': + i = 1; + if (!G.global_argv[i]) + break; + ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */ + if (!(first_ch & 0x80)) { /* unquoted $* or $@ */ + smallint sv = output->o_escape; + /* unquoted var's contents should be globbed, so don't escape */ + output->o_escape = 0; + while (G.global_argv[i]) { + n = expand_on_ifs(output, n, G.global_argv[i]); + debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1); + if (G.global_argv[i++][0] && G.global_argv[i]) { + /* this argv[] is not empty and not last: + * put terminating NUL, start new word */ + o_addchr(output, '\0'); + debug_print_list("expand_vars_to_list[2]", output, n); + n = o_save_ptr(output, n); + debug_print_list("expand_vars_to_list[3]", output, n); + } + } + output->o_escape = sv; + } else + /* If or_mask is nonzero, we handle assignment 'a=....$@.....' + * and in this case should treat it like '$*' - see 'else...' below */ + if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */ + while (1) { + o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i])); + if (++i >= G.global_argc) + break; + o_addchr(output, '\0'); + debug_print_list("expand_vars_to_list[4]", output, n); + n = o_save_ptr(output, n); + } + } else { /* quoted $*: add as one word */ + while (1) { + o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i])); + if (!G.global_argv[++i]) + break; + if (G.ifs[0]) + o_addchr(output, G.ifs[0]); + } + } + break; + case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */ + /* "Empty variable", used to make "" etc to not disappear */ + arg++; + ored_ch = 0x80; + break; +#if ENABLE_HUSH_TICK + case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */ + *p = '\0'; + arg++; + /* Can't just stuff it into output o_string, + * expanded result may need to be globbed + * and $IFS-splitted */ + debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch); + process_command_subs(&subst_result, arg); + debug_printf_subst("SUBST RES '%s'\n", subst_result.data); + val = subst_result.data; + goto store_val; +#endif +#if ENABLE_SH_MATH_SUPPORT + case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */ + arith_eval_hooks_t hooks; + arith_t res; + int errcode; + char *exp_str; + + arg++; /* skip '+' */ + *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */ + debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch); + + exp_str = expand_pseudo_dquoted(arg); + hooks.lookupvar = get_local_var_value; + hooks.setvar = arith_set_local_var; + hooks.endofname = endofname; + res = arith(exp_str ? exp_str : arg, &errcode, &hooks); + free(exp_str); + + if (errcode < 0) { + const char *msg = "error in arithmetic"; + switch (errcode) { + case -3: + msg = "exponent less than 0"; + break; + case -2: + msg = "divide by 0"; + break; + case -5: + msg = "expression recursion loop detected"; + break; + } + die_if_script(msg); + } + debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res); + sprintf(arith_buf, arith_t_fmt, res); + val = arith_buf; + break; + } +#endif + default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */ + case_default: { + bool exp_len = false; + bool exp_null = false; + char *var = arg; + char exp_save = exp_save; /* for compiler */ + char exp_op = exp_op; /* for compiler */ + char *exp_word = exp_word; /* for compiler */ + size_t exp_off = 0; + + *p = '\0'; + arg[0] = first_ch & 0x7f; + + /* prepare for expansions */ + if (var[0] == '#') { + /* handle length expansion ${#var} */ + exp_len = true; + ++var; + } else { + /* maybe handle parameter expansion */ + exp_off = strcspn(var, ":-=+?%#"); + if (!var[exp_off]) + exp_off = 0; + if (exp_off) { + exp_save = var[exp_off]; + exp_null = exp_save == ':'; + exp_word = var + exp_off; + if (exp_null) + ++exp_word; + exp_op = *exp_word++; + var[exp_off] = '\0'; + } + } + + /* lookup the variable in question */ + if (isdigit(var[0])) { + /* handle_dollar() should have vetted var for us */ + i = xatoi_u(var); + if (i < G.global_argc) + val = G.global_argv[i]; + /* else val remains NULL: $N with too big N */ + } else + val = get_local_var_value(var); + + /* handle any expansions */ + if (exp_len) { + debug_printf_expand("expand: length of '%s' = ", val); + val = utoa(val ? strlen(val) : 0); + debug_printf_expand("%s\n", val); + } else if (exp_off) { + if (exp_op == '%' || exp_op == '#') { + if (val) { + /* we need to do a pattern match */ + bool match_at_left; + char *loc; + scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left); + if (exp_op == *exp_word) /* ## or %% */ + ++exp_word; + val = dyn_val = xstrdup(val); + loc = scan(dyn_val, exp_word, match_at_left); + if (match_at_left) /* # or ## */ + val = loc; + else if (loc) /* % or %% and match was found */ + *loc = '\0'; + } + } else { + /* we need to do an expansion */ + int exp_test = (!val || (exp_null && !val[0])); + if (exp_op == '+') + exp_test = !exp_test; + debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op, + exp_null ? "true" : "false", exp_test); + if (exp_test) { + if (exp_op == '?') { +//TODO: how interactive bash aborts expansion mid-command? + /* ${var?[error_msg_if_unset]} */ + /* ${var:?[error_msg_if_unset_or_null]} */ + /* mimic bash message */ + die_if_script("%s: %s", + var, + exp_word[0] ? exp_word : "parameter null or not set" + ); + } else { + val = exp_word; + } + + if (exp_op == '=') { + /* ${var=[word]} or ${var:=[word]} */ + if (isdigit(var[0]) || var[0] == '#') { + /* mimic bash message */ + die_if_script("$%s: cannot assign in this way", var); + val = NULL; + } else { + char *new_var = xasprintf("%s=%s", var, val); + set_local_var(new_var, 0, 0); + } + } + } + } + + var[exp_off] = exp_save; + } + + arg[0] = first_ch; +#if ENABLE_HUSH_TICK + store_val: +#endif + if (!(first_ch & 0x80)) { /* unquoted $VAR */ + debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape); + if (val) { + /* unquoted var's contents should be globbed, so don't escape */ + smallint sv = output->o_escape; + output->o_escape = 0; + n = expand_on_ifs(output, n, val); + val = NULL; + output->o_escape = sv; + } + } else { /* quoted $VAR, val will be appended below */ + debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape); + } + } /* default: */ + } /* switch (char after <SPECIAL_VAR_SYMBOL>) */ + + if (val) { + o_addQstr(output, val, strlen(val)); + } + free(dyn_val); + /* Do the check to avoid writing to a const string */ + if (*p != SPECIAL_VAR_SYMBOL) + *p = SPECIAL_VAR_SYMBOL; + +#if ENABLE_HUSH_TICK + o_free(&subst_result); +#endif + arg = ++p; + } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */ + + if (arg[0]) { + debug_print_list("expand_vars_to_list[a]", output, n); + /* this part is literal, and it was already pre-quoted + * if needed (much earlier), do not use o_addQstr here! */ + o_addstr_with_NUL(output, arg); + debug_print_list("expand_vars_to_list[b]", output, n); + } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */ + && !(ored_ch & 0x80) /* and all vars were not quoted. */ + ) { + n--; + /* allow to reuse list[n] later without re-growth */ + output->has_empty_slot = 1; + } else { + o_addchr(output, '\0'); + } + return n; } -static void mark_open(int fd) +static char **expand_variables(char **argv, int or_mask) { - struct close_me *new = xmalloc(sizeof(struct close_me)); - new->fd = fd; - new->next = close_me_head; - close_me_head = new; + int n; + char **list; + char **v; + o_string output = NULL_O_STRING; + + if (or_mask & 0x100) { + output.o_escape = 1; /* protect against globbing for "$var" */ + /* (unquoted $var will temporarily switch it off) */ + output.o_glob = 1; + } + + n = 0; + v = argv; + while (*v) { + n = expand_vars_to_list(&output, n, *v, (char)or_mask); + v++; + } + debug_print_list("expand_variables", &output, n); + + /* output.data (malloced in one block) gets returned in "list" */ + list = o_finalize_list(&output, n); + debug_print_strings("expand_variables[1]", list); + return list; } -static void mark_closed(int fd) +static char **expand_strvec_to_strvec(char **argv) { - struct close_me *tmp; - if (close_me_head == NULL || close_me_head->fd != fd) - bb_error_msg_and_die("corrupt close_me"); - tmp = close_me_head; - close_me_head = close_me_head->next; - free(tmp); + return expand_variables(argv, 0x100); } -static void close_all(void) +/* Used for expansion of right hand of assignments */ +/* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs + * "v=/bin/c*" */ +static char *expand_string_to_string(const char *str) { - struct close_me *c; - for (c=close_me_head; c; c=c->next) { - close(c->fd); + char *argv[2], **list; + + argv[0] = (char*)str; + argv[1] = NULL; + list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */ + if (HUSH_DEBUG) + if (!list[0] || list[1]) + bb_error_msg_and_die("BUG in varexp2"); + /* actually, just move string 2*sizeof(char*) bytes back */ + overlapping_strcpy((char*)list, list[0]); + unbackslash((char*)list); + debug_printf_expand("string_to_string='%s'\n", (char*)list); + return (char*)list; +} + +/* Used for "eval" builtin */ +static char* expand_strvec_to_string(char **argv) +{ + char **list; + + list = expand_variables(argv, 0x80); + /* Convert all NULs to spaces */ + if (list[0]) { + int n = 1; + while (list[n]) { + if (HUSH_DEBUG) + if (list[n-1] + strlen(list[n-1]) + 1 != list[n]) + bb_error_msg_and_die("BUG in varexp3"); + /* bash uses ' ' regardless of $IFS contents */ + list[n][-1] = ' '; + n++; + } } - close_me_head = NULL; + overlapping_strcpy((char*)list, list[0]); + debug_printf_expand("strvec_to_string='%s'\n", (char*)list); + return (char*)list; +} + +static char **expand_assignments(char **argv, int count) +{ + int i; + char **p = NULL; + /* Expand assignments into one string each */ + for (i = 0; i < count; i++) { + p = add_string_to_strings(p, expand_string_to_string(argv[i])); + } + return p; +} + + +#if BB_MMU +/* never called */ +void re_execute_shell(char ***to_free, const char *s, char *argv0, char **argv); + +static void reset_traps_to_defaults(void) +{ + /* This function is always called in a child shell + * after fork (not vfork, NOMMU doesn't use this function). + * Child shells are not interactive. + * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling. + * Testcase: (while :; do :; done) + ^Z should background. + * Same goes for SIGTERM, SIGHUP, SIGINT. + */ + unsigned sig; + unsigned mask; + + if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS)) + return; + + /* Stupid. It can be done with *single* &= op, but we can't use + * the fact that G.blocked_set is implemented as a bitmask... */ + mask = (SPECIAL_INTERACTIVE_SIGS >> 1); + sig = 1; + while (1) { + if (mask & 1) + sigdelset(&G.blocked_set, sig); + mask >>= 1; + if (!mask) + break; + sig++; + } + + G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS; + mask = G.non_DFL_mask; + if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) { + if (!G.traps[sig]) + continue; + free(G.traps[sig]); + G.traps[sig] = NULL; + /* There is no signal for 0 (EXIT) */ + if (sig == 0) + continue; + /* There was a trap handler, we are removing it. + * But if sig still has non-DFL handling, + * we should not unblock it. */ + if (mask & 1) + continue; + sigdelset(&G.blocked_set, sig); + } + sigprocmask(SIG_SETMASK, &G.blocked_set, NULL); +} + +#else /* !BB_MMU */ + +static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv) NORETURN; +static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv) +{ + char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4]; + char *heredoc_argv[4]; + struct variable *cur; +#if ENABLE_HUSH_FUNCTIONS + struct function *funcp; +#endif + char **argv, **pp; + unsigned cnt; + + if (!g_argv0) { /* heredoc */ + argv = heredoc_argv; + argv[0] = (char *) G.argv0_for_re_execing; + argv[1] = (char *) "-<"; + argv[2] = (char *) s; + argv[3] = NULL; + pp = &argv[3]; /* used as pointer to empty environment */ + goto do_exec; + } + + sprintf(param_buf, "-$%x:%x:%x" USE_HUSH_LOOPS(":%x") + , (unsigned) G.root_pid + , (unsigned) G.last_bg_pid + , (unsigned) G.last_exitcode + USE_HUSH_LOOPS(, G.depth_of_loop) + ); + /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...> <funcs...> + * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL + */ + cnt = 6; + for (cur = G.top_var; cur; cur = cur->next) { + if (!cur->flg_export || cur->flg_read_only) + cnt += 2; + } +#if ENABLE_HUSH_FUNCTIONS + for (funcp = G.top_func; funcp; funcp = funcp->next) + cnt += 3; +#endif + pp = g_argv; + while (*pp++) + cnt++; + *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt); + *pp++ = (char *) G.argv0_for_re_execing; + *pp++ = param_buf; + for (cur = G.top_var; cur; cur = cur->next) { + if (cur->varstr == hush_version_str) + continue; + if (cur->flg_read_only) { + *pp++ = (char *) "-R"; + *pp++ = cur->varstr; + } else if (!cur->flg_export) { + *pp++ = (char *) "-V"; + *pp++ = cur->varstr; + } + } +#if ENABLE_HUSH_FUNCTIONS + for (funcp = G.top_func; funcp; funcp = funcp->next) { + *pp++ = (char *) "-F"; + *pp++ = funcp->name; + *pp++ = funcp->body_as_string; + } +#endif + /* We can pass activated traps here. Say, -Tnn:trap_string + * + * However, POSIX says that subshells reset signals with traps + * to SIG_DFL. + * I tested bash-3.2 and it not only does that with true subshells + * of the form ( list ), but with any forked children shells. + * I set trap "echo W" WINCH; and then tried: + * + * { echo 1; sleep 20; echo 2; } & + * while true; do echo 1; sleep 20; echo 2; break; done & + * true | { echo 1; sleep 20; echo 2; } | cat + * + * In all these cases sending SIGWINCH to the child shell + * did not run the trap. If I add trap "echo V" WINCH; + * _inside_ group (just before echo 1), it works. + * + * I conclude it means we don't need to pass active traps here. + * exec syscall below resets them to SIG_DFL for us. + */ + *pp++ = (char *) "-c"; + *pp++ = (char *) s; + *pp++ = g_argv0; + while (*g_argv) + *pp++ = *g_argv++; + /* *pp = NULL; - is already there */ + pp = environ; + + do_exec: + debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s); + sigprocmask(SIG_SETMASK, &G.inherited_set, NULL); + execve(bb_busybox_exec_path, argv, pp); + /* Fallback. Useful for init=/bin/hush usage etc */ + if (argv[0][0] == '/') + execve(argv[0], argv, pp); + xfunc_error_retval = 127; + bb_error_msg_and_die("can't re-execute the shell"); +} +#endif /* !BB_MMU */ + + +static void setup_heredoc(struct redir_struct *redir) +{ + struct fd_pair pair; + pid_t pid; + int len, written; + /* the _body_ of heredoc (misleading field name) */ + const char *heredoc = redir->rd_filename; + char *expanded; +#if !BB_MMU + char **to_free; +#endif + + expanded = NULL; + if (!(redir->rd_dup & HEREDOC_QUOTED)) { + expanded = expand_pseudo_dquoted(heredoc); + if (expanded) + heredoc = expanded; + } + len = strlen(heredoc); + + close(redir->rd_fd); /* often saves dup2+close in xmove_fd */ + xpiped_pair(pair); + xmove_fd(pair.rd, redir->rd_fd); + + /* Try writing without forking. Newer kernels have + * dynamically growing pipes. Must use non-blocking write! */ + ndelay_on(pair.wr); + while (1) { + written = write(pair.wr, heredoc, len); + if (written <= 0) + break; + len -= written; + if (len == 0) { + close(pair.wr); + free(expanded); + return; + } + heredoc += written; + } + ndelay_off(pair.wr); + + /* Okay, pipe buffer was not big enough */ + /* Note: we must not create a stray child (bastard? :) + * for the unsuspecting parent process. Child creates a grandchild + * and exits before parent execs the process which consumes heredoc + * (that exec happens after we return from this function) */ +#if !BB_MMU + to_free = NULL; +#endif + pid = vfork(); + if (pid < 0) + bb_perror_msg_and_die("vfork"); + if (pid == 0) { + /* child */ + disable_restore_tty_pgrp_on_exit(); + pid = BB_MMU ? fork() : vfork(); + if (pid < 0) + bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork"); + if (pid != 0) + _exit(0); + /* grandchild */ + close(redir->rd_fd); /* read side of the pipe */ +#if BB_MMU + full_write(pair.wr, heredoc, len); /* may loop or block */ + _exit(0); +#else + /* Delegate blocking writes to another process */ + xmove_fd(pair.wr, STDOUT_FILENO); + re_execute_shell(&to_free, heredoc, NULL, NULL); +#endif + } + /* parent */ +#if ENABLE_HUSH_FAST + G.count_SIGCHLD++; +//bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD); +#endif + enable_restore_tty_pgrp_on_exit(); +#if !BB_MMU + free(to_free); +#endif + close(pair.wr); + free(expanded); + wait(NULL); /* wait till child has died */ } /* squirrel != NULL means we squirrel away copies of stdin, stdout, * and stderr if they are redirected. */ -static int setup_redirects(struct child_prog *prog, int squirrel[]) +static int setup_redirects(struct command *prog, int squirrel[]) { int openfd, mode; struct redir_struct *redir; - for (redir=prog->redirects; redir; redir=redir->next) { - if (redir->dup == -1 && redir->word.gl_pathv == NULL) { - /* something went wrong in the parse. Pretend it didn't happen */ + for (redir = prog->redirects; redir; redir = redir->next) { + if (redir->rd_type == REDIRECT_HEREDOC2) { + /* rd_fd<<HERE case */ + if (squirrel && redir->rd_fd < 3 + && squirrel[redir->rd_fd] < 0 + ) { + squirrel[redir->rd_fd] = dup(redir->rd_fd); + } + /* for REDIRECT_HEREDOC2, rd_filename holds _contents_ + * of the heredoc */ + debug_printf_parse("set heredoc '%s'\n", + redir->rd_filename); + setup_heredoc(redir); continue; } - if (redir->dup == -1) { - mode=redir_table[redir->type].mode; - openfd = open(redir->word.gl_pathv[0], mode, 0666); + + if (redir->rd_dup == REDIRFD_TO_FILE) { + /* rd_fd<*>file case (<*> is <,>,>>,<>) */ + char *p; + if (redir->rd_filename == NULL) { + /* Something went wrong in the parse. + * Pretend it didn't happen */ + bb_error_msg("bug in redirect parse"); + continue; + } + mode = redir_table[redir->rd_type].mode; + p = expand_string_to_string(redir->rd_filename); + openfd = open_or_warn(p, mode); + free(p); if (openfd < 0) { /* this could get lost if stderr has been redirected, but - bash and ash both lose it as well (though zsh doesn't!) */ - bb_perror_msg("error opening %s", redir->word.gl_pathv[0]); + * bash and ash both lose it as well (though zsh doesn't!) */ +//what the above comment tries to say? return 1; } } else { - openfd = redir->dup; + /* rd_fd<*>rd_dup or rd_fd<*>- cases */ + openfd = redir->rd_dup; } - if (openfd != redir->fd) { - if (squirrel && redir->fd < 3) { - squirrel[redir->fd] = dup(redir->fd); + if (openfd != redir->rd_fd) { + if (squirrel && redir->rd_fd < 3 + && squirrel[redir->rd_fd] < 0 + ) { + squirrel[redir->rd_fd] = dup(redir->rd_fd); } - if (openfd == -3) { - close(openfd); + if (openfd == REDIRFD_CLOSE) { + /* "n>-" means "close me" */ + close(redir->rd_fd); } else { - dup2(openfd, redir->fd); - if (redir->dup == -1) - close (openfd); + xdup2(openfd, redir->rd_fd); + if (redir->rd_dup == REDIRFD_TO_FILE) + close(openfd); } } } @@ -1057,1184 +2762,1976 @@ static int setup_redirects(struct child_prog *prog, int squirrel[]) static void restore_redirects(int squirrel[]) { int i, fd; - for (i=0; i<3; i++) { + for (i = 0; i < 3; i++) { fd = squirrel[i]; if (fd != -1) { - /* No error checking. I sure wouldn't know what - * to do with an error if I found one! */ - dup2(fd, i); - close(fd); + /* We simply die on error */ + xmove_fd(fd, i); } } } -/* never returns */ -/* XXX no exit() here. If you don't exec, use _exit instead. + +static void free_pipe_list(struct pipe *head); + +/* Return code is the exit status of the pipe */ +static void free_pipe(struct pipe *pi) +{ + char **p; + struct command *command; + struct redir_struct *r, *rnext; + int a, i; + + if (pi->stopped_cmds > 0) /* why? */ + return; + debug_printf_clean("run pipe: (pid %d)\n", getpid()); + for (i = 0; i < pi->num_cmds; i++) { + command = &pi->cmds[i]; + debug_printf_clean(" command %d:\n", i); + if (command->argv) { + for (a = 0, p = command->argv; *p; a++, p++) { + debug_printf_clean(" argv[%d] = %s\n", a, *p); + } + free_strings(command->argv); + command->argv = NULL; + } + /* not "else if": on syntax error, we may have both! */ + if (command->group) { + debug_printf_clean(" begin group (grp_type:%d)\n", + command->grp_type); + free_pipe_list(command->group); + debug_printf_clean(" end group\n"); + command->group = NULL; + } + /* else is crucial here. + * If group != NULL, child_func is meaningless */ +#if ENABLE_HUSH_FUNCTIONS + else if (command->child_func) { + debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func); + command->child_func->parent_cmd = NULL; + } +#endif +#if !BB_MMU + free(command->group_as_string); + command->group_as_string = NULL; +#endif + for (r = command->redirects; r; r = rnext) { + debug_printf_clean(" redirect %d%s", + r->rd_fd, redir_table[r->rd_type].descrip); + /* guard against the case >$FOO, where foo is unset or blank */ + if (r->rd_filename) { + debug_printf_clean(" fname:'%s'\n", r->rd_filename); + free(r->rd_filename); + r->rd_filename = NULL; + } + debug_printf_clean(" rd_dup:%d\n", r->rd_dup); + rnext = r->next; + free(r); + } + command->redirects = NULL; + } + free(pi->cmds); /* children are an array, they get freed all at once */ + pi->cmds = NULL; +#if ENABLE_HUSH_JOB + free(pi->cmdtext); + pi->cmdtext = NULL; +#endif +} + +static void free_pipe_list(struct pipe *head) +{ + struct pipe *pi, *next; + + for (pi = head; pi; pi = next) { +#if HAS_KEYWORDS + debug_printf_clean(" pipe reserved word %d\n", pi->res_word); +#endif + free_pipe(pi); + debug_printf_clean("pipe followup code %d\n", pi->followup); + next = pi->next; + /*pi->next = NULL;*/ + free(pi); + } +} + + +static int run_list(struct pipe *pi); +#if BB_MMU +#define parse_stream(pstring, input, end_trigger) \ + parse_stream(input, end_trigger) +#endif +static struct pipe *parse_stream(char **pstring, + struct in_str *input, + int end_trigger); +static void parse_and_run_string(const char *s); + + +static const struct built_in_command* find_builtin(const char *name) +{ + const struct built_in_command *x; + for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) { + if (strcmp(name, x->cmd) != 0) + continue; + debug_printf_exec("found builtin '%s'\n", name); + return x; + } + return NULL; +} + +#if ENABLE_HUSH_FUNCTIONS +static const struct function *find_function(const char *name) +{ + const struct function *funcp = G.top_func; + while (funcp) { + if (strcmp(name, funcp->name) == 0) { + break; + } + funcp = funcp->next; + } + if (funcp) + debug_printf_exec("found function '%s'\n", name); + return funcp; +} + +/* Note: takes ownership on name ptr */ +static struct function *new_function(char *name) +{ + struct function *funcp; + struct function **funcpp = &G.top_func; + + while ((funcp = *funcpp) != NULL) { + struct command *cmd; + + if (strcmp(funcp->name, name) != 0) { + funcpp = &funcp->next; + continue; + } + + cmd = funcp->parent_cmd; + debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd); + if (!cmd) { + debug_printf_exec("freeing & replacing function '%s'\n", funcp->name); + free(funcp->name); + /* Note: if !funcp->body, do not free body_as_string! + * This is a special case of "-F name body" function: + * body_as_string was not malloced! */ + if (funcp->body) { + free_pipe_list(funcp->body); +# if !BB_MMU + free(funcp->body_as_string); +# endif + } + } else { + debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name); + cmd->argv[0] = funcp->name; + cmd->group = funcp->body; +# if !BB_MMU + cmd->group_as_string = funcp->body_as_string; +# endif + } + goto skip; + } + debug_printf_exec("remembering new function '%s'\n", name); + funcp = *funcpp = xzalloc(sizeof(*funcp)); + /*funcp->next = NULL;*/ + skip: + funcp->name = name; + return funcp; +} + +static void unset_func(const char *name) +{ + struct function *funcp; + struct function **funcpp = &G.top_func; + + while ((funcp = *funcpp) != NULL) { + if (strcmp(funcp->name, name) == 0) { + *funcpp = funcp->next; + /* funcp is unlinked now, deleting it. + * Note: if !funcp->body, the function was created by + * "-F name body", do not free ->body_as_string + * and ->name as they were not malloced. */ + if (funcp->body) { + free_pipe_list(funcp->body); + free(funcp->name); +# if !BB_MMU + free(funcp->body_as_string); +# endif + } + free(funcp); + break; + } + funcpp = &funcp->next; + } +} + +# if BB_MMU +#define exec_function(nommu_save, funcp, argv) \ + exec_function(funcp, argv) +# endif +static void exec_function(nommu_save_t *nommu_save, + const struct function *funcp, + char **argv) NORETURN; +static void exec_function(nommu_save_t *nommu_save, + const struct function *funcp, + char **argv) +{ +# if BB_MMU + int n = 1; + + argv[0] = G.global_argv[0]; + G.global_argv = argv; + while (*++argv) + n++; + G.global_argc = n; + /* On MMU, funcp->body is always non-NULL */ + n = run_list(funcp->body); + fflush(NULL); + _exit(n); +# else + re_execute_shell(&nommu_save->argv_from_re_execing, + funcp->body_as_string, + G.global_argv[0], + argv + 1); +# endif +} + +static int run_function(const struct function *funcp, char **argv) +{ + int rc; + save_arg_t sv; + smallint sv_flg; + + save_and_replace_G_args(&sv, argv); + /* "we are in function, ok to use return" */ + sv_flg = G.flag_return_in_progress; + G.flag_return_in_progress = -1; + + /* On MMU, funcp->body is always non-NULL */ +# if !BB_MMU + if (!funcp->body) { + /* Function defined by -F */ + parse_and_run_string(funcp->body_as_string); + rc = G.last_exitcode; + } else +# endif + { + rc = run_list(funcp->body); + } + + G.flag_return_in_progress = sv_flg; + restore_G_args(&sv, argv); + + return rc; +} +#endif /* ENABLE_HUSH_FUNCTIONS */ + + +#if BB_MMU +#define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \ + pseudo_exec_argv(argv, assignment_cnt, argv_expanded) +#define pseudo_exec(nommu_save, command, argv_expanded) \ + pseudo_exec(command, argv_expanded) +#endif + +/* Called after [v]fork() in run_pipe, or from builtin_exec. + * Never returns. + * Don't exit() here. If you don't exec, use _exit instead. * The at_exit handlers apparently confuse the calling process, - * in particular stdin handling. Not sure why? */ -static void pseudo_exec(struct child_prog *child) + * in particular stdin handling. Not sure why? -- because of vfork! (vda) */ +static void pseudo_exec_argv(nommu_save_t *nommu_save, + char **argv, int assignment_cnt, + char **argv_expanded) NORETURN; +static void pseudo_exec_argv(nommu_save_t *nommu_save, + char **argv, int assignment_cnt, + char **argv_expanded) { - int i, rcode; - char *p; - struct built_in_command *x; - if (child->argv) { - for (i=0; is_assignment(child->argv[i]); i++) { - debug_printf("pid %d environment modification: %s\n",getpid(),child->argv[i]); - p = insert_var_value(child->argv[i]); - putenv(strdup(p)); - if (p != child->argv[i]) free(p); - } - child->argv+=i; /* XXX this hack isn't so horrible, since we are about - to exit, and therefore don't need to keep data - structures consistent for free() use. */ - /* If a variable is assigned in a forest, and nobody listens, - * was it ever really set? - */ - if (child->argv[0] == NULL) { - _exit(EXIT_SUCCESS); + char **new_env; + + /* Case when we are here: ... | var=val | ... */ + if (!argv[assignment_cnt]) + _exit(EXIT_SUCCESS); + + new_env = expand_assignments(argv, assignment_cnt); +#if BB_MMU + set_vars_and_save_old(new_env); + free(new_env); /* optional */ + /* we can also destroy set_vars_and_save_old's return value, + * to save memory */ +#else + nommu_save->new_env = new_env; + nommu_save->old_vars = set_vars_and_save_old(new_env); +#endif + if (argv_expanded) { + argv = argv_expanded; + } else { + argv = expand_strvec_to_strvec(argv + assignment_cnt); +#if !BB_MMU + nommu_save->argv = argv; +#endif + } + +#if ENABLE_FEATURE_SH_STANDALONE || BB_MMU + if (strchr(argv[0], '/') != NULL) + goto skip; +#endif + + /* On NOMMU, we must never block! + * Example: { sleep 99999 | read line } & echo Ok + * read builtin will block on read syscall, leaving parent blocked + * in vfork. Therefore we can't do this: + */ +#if BB_MMU + /* Check if the command matches any of the builtins. + * Depending on context, this might be redundant. But it's + * easier to waste a few CPU cycles than it is to figure out + * if this is one of those cases. + */ + { + int rcode; + const struct built_in_command *x = find_builtin(argv[0]); + if (x) { + rcode = x->function(argv); + fflush(NULL); + _exit(rcode); + } + } +#endif +#if ENABLE_HUSH_FUNCTIONS + /* Check if the command matches any functions */ + { + const struct function *funcp = find_function(argv[0]); + if (funcp) { + exec_function(nommu_save, funcp, argv); } + } +#endif - /* - * Check if the command matches any of the builtins. - * Depending on context, this might be redundant. But it's - * easier to waste a few CPU cycles than it is to figure out - * if this is one of those cases. +#if ENABLE_FEATURE_SH_STANDALONE + /* Check if the command matches any busybox applets */ + { + int a = find_applet_by_name(argv[0]); + if (a >= 0) { +# if BB_MMU /* see above why on NOMMU it is not allowed */ + if (APPLET_IS_NOEXEC(a)) { + debug_printf_exec("running applet '%s'\n", argv[0]); + run_applet_no_and_exit(a, argv); + } +# endif + /* Re-exec ourselves */ + debug_printf_exec("re-execing applet '%s'\n", argv[0]); + sigprocmask(SIG_SETMASK, &G.inherited_set, NULL); + execv(bb_busybox_exec_path, argv); + /* If they called chroot or otherwise made the binary no longer + * executable, fall through */ + } + } +#endif + +#if ENABLE_FEATURE_SH_STANDALONE || BB_MMU + skip: +#endif + debug_printf_exec("execing '%s'\n", argv[0]); + sigprocmask(SIG_SETMASK, &G.inherited_set, NULL); + execvp(argv[0], argv); + bb_perror_msg("can't execute '%s'", argv[0]); + _exit(EXIT_FAILURE); +} + +/* Called after [v]fork() in run_pipe + */ +static void pseudo_exec(nommu_save_t *nommu_save, + struct command *command, + char **argv_expanded) NORETURN; +static void pseudo_exec(nommu_save_t *nommu_save, + struct command *command, + char **argv_expanded) +{ + if (command->argv) { + pseudo_exec_argv(nommu_save, command->argv, + command->assignment_cnt, argv_expanded); + } + + if (command->group) { + /* Cases when we are here: + * ( list ) + * { list } & + * ... | ( list ) | ... + * ... | { list } | ... */ - for (x = bltins; x->cmd; x++) { - if (strcmp(child->argv[0], x->cmd) == 0 ) { - debug_printf("builtin exec %s\n", child->argv[0]); - rcode = x->function(child); - fflush(stdout); - _exit(rcode); - } - } - - /* Check if the command matches any busybox internal commands - * ("applets") here. - * FIXME: This feature is not 100% safe, since - * BusyBox is not fully reentrant, so we have no guarantee the things - * from the .bss are still zeroed, or that things from .data are still - * at their defaults. We could exec ourself from /proc/self/exe, but I - * really dislike relying on /proc for things. We could exec ourself - * from global_argv[0], but if we are in a chroot, we may not be able - * to find ourself... */ -#ifdef CONFIG_FEATURE_SH_STANDALONE_SHELL - { - int argc_l; - char** argv_l=child->argv; - char *name = child->argv[0]; - -#ifdef CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN - /* Following discussions from November 2000 on the busybox mailing - * list, the default configuration, (without - * bb_get_last_path_component()) lets the user force use of an - * external command by specifying the full (with slashes) filename. - * If you enable CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN, then applets - * _aways_ override external commands, so if you want to run - * /bin/cat, it will use BusyBox cat even if /bin/cat exists on the - * filesystem and is _not_ busybox. Some systems may want this, - * most do not. */ - name = bb_get_last_path_component(name); -#endif - /* Count argc for use in a second... */ - for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++); - optind = 1; - debug_printf("running applet %s\n", name); - run_applet_by_name(name, argc_l, child->argv); - } -#endif - debug_printf("exec of %s\n",child->argv[0]); - execvp(child->argv[0],child->argv); - bb_perror_msg("couldn't exec: %s",child->argv[0]); - _exit(1); - } else if (child->group) { - debug_printf("runtime nesting to group\n"); - interactive=0; /* crucial!!!! */ - rcode = run_list_real(child->group); +#if BB_MMU + int rcode; + debug_printf_exec("pseudo_exec: run_list\n"); + reset_traps_to_defaults(); + rcode = run_list(command->group); /* OK to leak memory by not calling free_pipe_list, * since this process is about to exit */ _exit(rcode); - } else { - /* Can happen. See what bash does with ">foo" by itself. */ - debug_printf("trying to pseudo_exec null command\n"); - _exit(EXIT_SUCCESS); +#else + re_execute_shell(&nommu_save->argv_from_re_execing, + command->group_as_string, + G.global_argv[0], + G.global_argv + 1); +#endif } + + /* Case when we are here: ... | >file */ + debug_printf_exec("pseudo_exec'ed null command\n"); + _exit(EXIT_SUCCESS); } -static void insert_bg_job(struct pipe *pi) +#if ENABLE_HUSH_JOB +static const char *get_cmdtext(struct pipe *pi) { - struct pipe *thejob; - - /* Linear search for the ID of the job to use */ - pi->jobid = 1; - for (thejob = job_list; thejob; thejob = thejob->next) - if (thejob->jobid >= pi->jobid) - pi->jobid = thejob->jobid + 1; + char **argv; + char *p; + int len; - /* add thejob to the list of running jobs */ - if (!job_list) { - thejob = job_list = xmalloc(sizeof(*thejob)); - } else { - for (thejob = job_list; thejob->next; thejob = thejob->next) /* nothing */; - thejob->next = xmalloc(sizeof(*thejob)); - thejob = thejob->next; + /* This is subtle. ->cmdtext is created only on first backgrounding. + * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...) + * On subsequent bg argv is trashed, but we won't use it */ + if (pi->cmdtext) + return pi->cmdtext; + argv = pi->cmds[0].argv; + if (!argv || !argv[0]) { + pi->cmdtext = xzalloc(1); + return pi->cmdtext; } - /* physically copy the struct job */ - memcpy(thejob, pi, sizeof(struct pipe)); - thejob->next = NULL; - thejob->running_progs = thejob->num_progs; - thejob->stopped_progs = 0; - thejob->text = xmalloc(BUFSIZ); /* cmdedit buffer size */ + len = 0; + do { + len += strlen(*argv) + 1; + } while (*++argv); + p = xmalloc(len); + pi->cmdtext = p; + argv = pi->cmds[0].argv; + do { + len = strlen(*argv); + memcpy(p, *argv, len); + p += len; + *p++ = ' '; + } while (*++argv); + p[-1] = '\0'; + return pi->cmdtext; +} - //if (pi->progs[0] && pi->progs[0].argv && pi->progs[0].argv[0]) - { - char *bar=thejob->text; - char **foo=pi->progs[0].argv; - while(foo && *foo) { - bar += sprintf(bar, "%s ", *foo++); - } +static void insert_bg_job(struct pipe *pi) +{ + struct pipe *job, **jobp; + int i; + + /* Linear search for the ID of the job to use */ + pi->jobid = 1; + for (job = G.job_list; job; job = job->next) + if (job->jobid >= pi->jobid) + pi->jobid = job->jobid + 1; + + /* Add job to the list of running jobs */ + jobp = &G.job_list; + while ((job = *jobp) != NULL) + jobp = &job->next; + job = *jobp = xmalloc(sizeof(*job)); + + *job = *pi; /* physical copy */ + job->next = NULL; + job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds); + /* Cannot copy entire pi->cmds[] vector! This causes double frees */ + for (i = 0; i < pi->num_cmds; i++) { + job->cmds[i].pid = pi->cmds[i].pid; + /* all other fields are not used and stay zero */ } + job->cmdtext = xstrdup(get_cmdtext(pi)); - /* we don't wait for background thejobs to return -- append it - to the list of backgrounded thejobs and leave it alone */ - printf("[%d] %d\n", thejob->jobid, thejob->progs[0].pid); - last_bg_pid = thejob->progs[0].pid; - last_jobid = thejob->jobid; + if (G_interactive_fd) + printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext); + /* Last command's pid goes to $! */ + G.last_bg_pid = job->cmds[job->num_cmds - 1].pid; + G.last_jobid = job->jobid; } -/* remove a backgrounded job */ static void remove_bg_job(struct pipe *pi) { struct pipe *prev_pipe; - if (pi == job_list) { - job_list = pi->next; + if (pi == G.job_list) { + G.job_list = pi->next; } else { - prev_pipe = job_list; + prev_pipe = G.job_list; while (prev_pipe->next != pi) prev_pipe = prev_pipe->next; prev_pipe->next = pi->next; } - if (job_list) - last_jobid = job_list->jobid; + if (G.job_list) + G.last_jobid = G.job_list->jobid; else - last_jobid = 0; + G.last_jobid = 0; +} - pi->stopped_progs = 0; - free_pipe(pi, 0); +/* Remove a backgrounded job */ +static void delete_finished_bg_job(struct pipe *pi) +{ + remove_bg_job(pi); + pi->stopped_cmds = 0; + free_pipe(pi); free(pi); } +#endif /* JOB */ -/* Checks to see if any processes have exited -- if they - have, figure out why and see if a job has completed */ +/* Check to see if any processes have exited -- if they + * have, figure out why and see if a job has completed */ static int checkjobs(struct pipe* fg_pipe) { int attributes; int status; - int prognum = 0; +#if ENABLE_HUSH_JOB struct pipe *pi; +#endif pid_t childpid; + int rcode = 0; + + debug_printf_jobs("checkjobs %p\n", fg_pipe); attributes = WUNTRACED; - if (fg_pipe==NULL) { + if (fg_pipe == NULL) attributes |= WNOHANG; + + errno = 0; +#if ENABLE_HUSH_FAST + if (G.handled_SIGCHLD == G.count_SIGCHLD) { +//bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p", +//getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe); + /* There was neither fork nor SIGCHLD since last waitpid */ + /* Avoid doing waitpid syscall if possible */ + if (!G.we_have_children) { + errno = ECHILD; + return -1; + } + if (fg_pipe == NULL) { /* is WNOHANG set? */ + /* We have children, but they did not exit + * or stop yet (we saw no SIGCHLD) */ + return 0; + } + /* else: !WNOHANG, waitpid will block, can't short-circuit */ } +#endif + +/* Do we do this right? + * bash-3.00# sleep 20 | false + * <ctrl-Z pressed> + * [3]+ Stopped sleep 20 | false + * bash-3.00# echo $? + * 1 <========== bg pipe is not fully done, but exitcode is already known! + * [hush 1.14.0: yes we do it right] + */ + wait_more: + while (1) { + int i; + int dead; - while ((childpid = waitpid(-1, &status, attributes)) > 0) { +#if ENABLE_HUSH_FAST + i = G.count_SIGCHLD; +#endif + childpid = waitpid(-1, &status, attributes); + if (childpid <= 0) { + if (childpid && errno != ECHILD) + bb_perror_msg("waitpid"); +#if ENABLE_HUSH_FAST + else { /* Until next SIGCHLD, waitpid's are useless */ + G.we_have_children = (childpid == 0); + G.handled_SIGCHLD = i; +//bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD); + } +#endif + break; + } + dead = WIFEXITED(status) || WIFSIGNALED(status); + +#if DEBUG_JOBS + if (WIFSTOPPED(status)) + debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n", + childpid, WSTOPSIG(status), WEXITSTATUS(status)); + if (WIFSIGNALED(status)) + debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n", + childpid, WTERMSIG(status), WEXITSTATUS(status)); + if (WIFEXITED(status)) + debug_printf_jobs("pid %d exited, exitcode %d\n", + childpid, WEXITSTATUS(status)); +#endif + /* Were we asked to wait for fg pipe? */ if (fg_pipe) { - int i, rcode = 0; - for (i=0; i < fg_pipe->num_progs; i++) { - if (fg_pipe->progs[i].pid == childpid) { - if (i==fg_pipe->num_progs-1) - rcode=WEXITSTATUS(status); - (fg_pipe->num_progs)--; - return(rcode); + for (i = 0; i < fg_pipe->num_cmds; i++) { + debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid); + if (fg_pipe->cmds[i].pid != childpid) + continue; + if (dead) { + fg_pipe->cmds[i].pid = 0; + fg_pipe->alive_cmds--; + if (i == fg_pipe->num_cmds - 1) { + /* last process gives overall exitstatus */ + /* Note: is WIFSIGNALED, WEXITSTATUS = sig + 128 */ + rcode = WEXITSTATUS(status); + IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;) + /* bash prints killing signal's name for *last* + * process in pipe (prints just newline for SIGINT). + * Mimic this. Example: "sleep 5" + ^\ + */ + if (WIFSIGNALED(status)) { + int sig = WTERMSIG(status); + printf("%s\n", sig == SIGINT ? "" : get_signame(sig)); + } + } + } else { + fg_pipe->cmds[i].is_stopped = 1; + fg_pipe->stopped_cmds++; + } + debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n", + fg_pipe->alive_cmds, fg_pipe->stopped_cmds); + if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) { + /* All processes in fg pipe have exited or stopped */ +/* Note: *non-interactive* bash does not continue if all processes in fg pipe + * are stopped. Testcase: "cat | cat" in a script (not on command line!) + * and "killall -STOP cat" */ + if (G_interactive_fd) { +#if ENABLE_HUSH_JOB + if (fg_pipe->alive_cmds) + insert_bg_job(fg_pipe); +#endif + return rcode; + } + if (!fg_pipe->alive_cmds) + return rcode; } + /* There are still running processes in the fg pipe */ + goto wait_more; /* do waitpid again */ } + /* it wasnt fg_pipe, look for process in bg pipes */ } - for (pi = job_list; pi; pi = pi->next) { - prognum = 0; - while (prognum < pi->num_progs && pi->progs[prognum].pid != childpid) { - prognum++; +#if ENABLE_HUSH_JOB + /* We asked to wait for bg or orphaned children */ + /* No need to remember exitcode in this case */ + for (pi = G.job_list; pi; pi = pi->next) { + for (i = 0; i < pi->num_cmds; i++) { + if (pi->cmds[i].pid == childpid) + goto found_pi_and_prognum; } - if (prognum < pi->num_progs) - break; - } - - if(pi==NULL) { - debug_printf("checkjobs: pid %d was not in our list!\n", childpid); - continue; } + /* Happens when shell is used as init process (init=/bin/sh) */ + debug_printf("checkjobs: pid %d was not in our list!\n", childpid); + continue; /* do waitpid again */ - if (WIFEXITED(status) || WIFSIGNALED(status)) { + found_pi_and_prognum: + if (dead) { /* child exited */ - pi->running_progs--; - pi->progs[prognum].pid = 0; - - if (!pi->running_progs) { - printf(JOB_STATUS_FORMAT, pi->jobid, "Done", pi->text); - remove_bg_job(pi); + pi->cmds[i].pid = 0; + pi->alive_cmds--; + if (!pi->alive_cmds) { + if (G_interactive_fd) + printf(JOB_STATUS_FORMAT, pi->jobid, + "Done", pi->cmdtext); + delete_finished_bg_job(pi); } } else { /* child stopped */ - pi->stopped_progs++; - pi->progs[prognum].is_stopped = 1; - -#if 0 - /* Printing this stuff is a pain, since it tends to - * overwrite the prompt an inconveinient moments. So - * don't do that. */ - if (pi->stopped_progs == pi->num_progs) { - printf("\n"JOB_STATUS_FORMAT, pi->jobid, "Stopped", pi->text); - } -#endif + pi->cmds[i].is_stopped = 1; + pi->stopped_cmds++; } - } - - if (childpid == -1 && errno != ECHILD) - bb_perror_msg("waitpid"); +#endif + } /* while (waitpid succeeds)... */ - /* move the shell to the foreground */ - //if (interactive && tcsetpgrp(shell_terminal, getpgid(0))) - // bb_perror_msg("tcsetpgrp-2"); - return -1; + return rcode; } -/* Figure out our controlling tty, checking in order stderr, - * stdin, and stdout. If check_pgrp is set, also check that - * we belong to the foreground process group associated with - * that tty. The value of shell_terminal is needed in order to call - * tcsetpgrp(shell_terminal, ...); */ -void controlling_tty(int check_pgrp) +#if ENABLE_HUSH_JOB +static int checkjobs_and_fg_shell(struct pipe* fg_pipe) { - pid_t curpgrp; - - if ((curpgrp = tcgetpgrp(shell_terminal = 2)) < 0 - && (curpgrp = tcgetpgrp(shell_terminal = 0)) < 0 - && (curpgrp = tcgetpgrp(shell_terminal = 1)) < 0) - goto shell_terminal_error; - - if (check_pgrp && curpgrp != getpgid(0)) - goto shell_terminal_error; - - return; - -shell_terminal_error: - shell_terminal = -1; - return; + pid_t p; + int rcode = checkjobs(fg_pipe); + if (G_saved_tty_pgrp) { + /* Job finished, move the shell to the foreground */ + p = getpgrp(); /* our process group id */ + debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p); + tcsetpgrp(G_interactive_fd, p); + } + return rcode; } +#endif -/* run_pipe_real() starts all the jobs, but doesn't wait for anything - * to finish. See checkjobs(). +/* Start all the jobs, but don't wait for anything to finish. + * See checkjobs(). * - * return code is normally -1, when the caller has to wait for children + * Return code is normally -1, when the caller has to wait for children * to finish to determine the exit status of the pipe. If the pipe * is a simple builtin command, however, the action is done by the - * time run_pipe_real returns, and the exit code is provided as the + * time run_pipe returns, and the exit code is provided as the * return value. * - * The input of the pipe is always stdin, the output is always - * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus, - * because it tries to avoid running the command substitution in - * subshell, when that is in fact necessary. The subshell process - * now has its stdout directed to the input of the appropriate pipe, - * so this routine is noticeably simpler. + * Returns -1 only if started some children. IOW: we have to + * mask out retvals of builtins etc with 0xff! + * + * The only case when we do not need to [v]fork is when the pipe + * is single, non-backgrounded, non-subshell command. Examples: + * cmd ; ... { list } ; ... + * cmd && ... { list } && ... + * cmd || ... { list } || ... + * If it is, then we can run cmd as a builtin, NOFORK [do we do this?], + * or (if SH_STANDALONE) an applet, and we can run the { list } + * with run_list. If it isn't one of these, we fork and exec cmd. + * + * Cases when we must fork: + * non-single: cmd | cmd + * backgrounded: cmd & { list } & + * subshell: ( list ) [&] */ -static int run_pipe_real(struct pipe *pi) +static int run_pipe(struct pipe *pi) { + static const char *const null_ptr = NULL; int i; - int nextin, nextout; - int pipefds[2]; /* pipefds[0] is for reading */ - struct child_prog *child; - struct built_in_command *x; + int nextin; + struct command *command; + char **argv_expanded; + char **argv; char *p; + /* it is not always needed, but we aim to smaller code */ + int squirrel[] = { -1, -1, -1 }; + int rcode; - nextin = 0; - pi->pgrp = -1; + debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds); + debug_enter(); - /* Check if this is a simple builtin (not part of a pipe). - * Builtins within pipes have to fork anyway, and are handled in - * pseudo_exec. "echo foo | read bar" doesn't work on bash, either. - */ - if (pi->num_progs == 1) child = & (pi->progs[0]); - if (pi->num_progs == 1 && child->group && child->subshell == 0) { - int squirrel[] = {-1, -1, -1}; - int rcode; - debug_printf("non-subshell grouping\n"); - setup_redirects(child, squirrel); - /* XXX could we merge code with following builtin case, - * by creating a pseudo builtin that calls run_list_real? */ - rcode = run_list_real(child->group); - restore_redirects(squirrel); - return rcode; - } else if (pi->num_progs == 1 && pi->progs[0].argv != NULL) { - for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ } - if (i!=0 && child->argv[i]==NULL) { - /* assignments, but no command: set the local environment */ - for (i=0; child->argv[i]!=NULL; i++) { - - /* Ok, this case is tricky. We have to decide if this is a - * local variable, or an already exported variable. If it is - * already exported, we have to export the new value. If it is - * not exported, we need only set this as a local variable. - * This junk is all to decide whether or not to export this - * variable. */ - int export_me=0; - char *name, *value; - name = bb_xstrdup(child->argv[i]); - debug_printf("Local environment set: %s\n", name); - value = strchr(name, '='); - if (value) - *value=0; - if ( get_local_var(name)) { - export_me=1; - } - free(name); - p = insert_var_value(child->argv[i]); - set_local_var(p, export_me); - if (p != child->argv[i]) free(p); - } - return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */ - } - for (i = 0; is_assignment(child->argv[i]); i++) { - p = insert_var_value(child->argv[i]); - putenv(strdup(p)); - if (p != child->argv[i]) { - child->sp--; - free(p); - } - } - if (child->sp) { - char * str = NULL; - - str = make_string((child->argv + i)); - parse_string_outer(str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING); - free(str); - return last_return_code; - } - for (x = bltins; x->cmd; x++) { - if (strcmp(child->argv[i], x->cmd) == 0 ) { - int squirrel[] = {-1, -1, -1}; - int rcode; - if (x->function == builtin_exec && child->argv[i+1]==NULL) { - debug_printf("magic exec\n"); - setup_redirects(child,NULL); - return EXIT_SUCCESS; - } - debug_printf("builtin inline %s\n", child->argv[0]); - /* XXX setup_redirects acts on file descriptors, not FILEs. - * This is perfect for work that comes after exec(). - * Is it really safe for inline use? Experimentally, - * things seem to work with glibc. */ - setup_redirects(child, squirrel); - child->argv+=i; /* XXX horrible hack */ - rcode = x->function(child); - child->argv-=i; /* XXX restore hack so free() can work right */ - restore_redirects(squirrel); - return rcode; - } - } - } + USE_HUSH_JOB(pi->pgrp = -1;) + pi->stopped_cmds = 0; + command = &(pi->cmds[0]); + argv_expanded = NULL; - for (i = 0; i < pi->num_progs; i++) { - child = & (pi->progs[i]); + if (pi->num_cmds != 1 + || pi->followup == PIPE_BG + || command->grp_type == GRP_SUBSHELL + ) { + goto must_fork; + } - /* pipes are inserted between pairs of commands */ - if ((i + 1) < pi->num_progs) { - if (pipe(pipefds)<0) bb_perror_msg_and_die("pipe"); - nextout = pipefds[1]; - } else { - nextout=1; - pipefds[0] = -1; + pi->alive_cmds = 1; + + debug_printf_exec(": group:%p argv:'%s'\n", + command->group, command->argv ? command->argv[0] : "NONE"); + + if (command->group) { +#if ENABLE_HUSH_FUNCTIONS + if (command->grp_type == GRP_FUNCTION) { + /* "executing" func () { list } */ + struct function *funcp; + + funcp = new_function(command->argv[0]); + /* funcp->name is already set to argv[0] */ + funcp->body = command->group; +# if !BB_MMU + funcp->body_as_string = command->group_as_string; + command->group_as_string = NULL; +# endif + command->group = NULL; + command->argv[0] = NULL; + debug_printf_exec("cmd %p has child func at %p\n", command, funcp); + funcp->parent_cmd = command; + command->child_func = funcp; + + debug_printf_exec("run_pipe: return EXIT_SUCCESS\n"); + debug_leave(); + return EXIT_SUCCESS; + } +#endif + /* { list } */ + debug_printf("non-subshell group\n"); + rcode = 1; /* exitcode if redir failed */ + if (setup_redirects(command, squirrel) == 0) { + debug_printf_exec(": run_list\n"); + rcode = run_list(command->group) & 0xff; } + restore_redirects(squirrel); + IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;) + debug_leave(); + debug_printf_exec("run_pipe: return %d\n", rcode); + return rcode; + } - /* XXX test for failed fork()? */ -#if !defined(__UCLIBC__) || defined(__UCLIBC_HAS_MMU__) - if (!(child->pid = fork())) + argv = command->argv ? command->argv : (char **) &null_ptr; + { + const struct built_in_command *x; +#if ENABLE_HUSH_FUNCTIONS + const struct function *funcp; #else - if (!(child->pid = vfork())) + enum { funcp = 0 }; #endif - { - /* Set the handling for job control signals back to the default. */ - signal(SIGINT, SIG_DFL); - signal(SIGQUIT, SIG_DFL); - signal(SIGTERM, SIG_DFL); - signal(SIGTSTP, SIG_DFL); - signal(SIGTTIN, SIG_DFL); - signal(SIGTTOU, SIG_DFL); - signal(SIGCHLD, SIG_DFL); - - close_all(); - - if (nextin != 0) { - dup2(nextin, 0); - close(nextin); - } - if (nextout != 1) { - dup2(nextout, 1); - close(nextout); - } - if (pipefds[0]!=-1) { - close(pipefds[0]); /* opposite end of our output pipe */ + char **new_env = NULL; + struct variable *old_vars = NULL; + + if (argv[command->assignment_cnt] == NULL) { + /* Assignments, but no command */ + /* Ensure redirects take effect. Try "a=t >file" */ + rcode = setup_redirects(command, squirrel); + restore_redirects(squirrel); + /* Set shell variables */ + while (*argv) { + p = expand_string_to_string(*argv); + debug_printf_exec("set shell var:'%s'->'%s'\n", + *argv, p); + set_local_var(p, 0, 0); + argv++; } + /* Do we need to flag set_local_var() errors? + * "assignment to readonly var" and "putenv error" + */ + IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;) + debug_leave(); + debug_printf_exec("run_pipe: return %d\n", rcode); + return rcode; + } - /* Like bash, explicit redirects override pipes, - * and the pipe fd is available for dup'ing. */ - setup_redirects(child,NULL); + /* Expand the rest into (possibly) many strings each */ + argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt); - if (interactive && pi->followup!=PIPE_BG) { - /* If we (the child) win the race, put ourselves in the process - * group whose leader is the first process in this pipe. */ - if (pi->pgrp < 0) { - pi->pgrp = getpid(); + x = find_builtin(argv_expanded[0]); +#if ENABLE_HUSH_FUNCTIONS + funcp = NULL; + if (!x) + funcp = find_function(argv_expanded[0]); +#endif + if (x || funcp) { + if (!funcp) { + if (x->function == builtin_exec && argv_expanded[1] == NULL) { + debug_printf("exec with redirects only\n"); + rcode = setup_redirects(command, NULL); + goto clean_up_and_ret1; + } + } + /* setup_redirects acts on file descriptors, not FILEs. + * This is perfect for work that comes after exec(). + * Is it really safe for inline use? Experimentally, + * things seem to work. */ + rcode = setup_redirects(command, squirrel); + if (rcode == 0) { + new_env = expand_assignments(argv, command->assignment_cnt); + old_vars = set_vars_and_save_old(new_env); + if (!funcp) { + debug_printf_exec(": builtin '%s' '%s'...\n", + x->cmd, argv_expanded[1]); + rcode = x->function(argv_expanded) & 0xff; + fflush(NULL); } - if (setpgid(0, pi->pgrp) == 0) { - tcsetpgrp(2, pi->pgrp); +#if ENABLE_HUSH_FUNCTIONS + else { + debug_printf_exec(": function '%s' '%s'...\n", + funcp->name, argv_expanded[1]); + rcode = run_function(funcp, argv_expanded) & 0xff; } +#endif } - - pseudo_exec(child); +#if ENABLE_FEATURE_SH_STANDALONE + clean_up_and_ret: +#endif + restore_redirects(squirrel); + unset_vars(new_env); + add_vars(old_vars); + clean_up_and_ret1: + free(argv_expanded); + IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;) + debug_leave(); + debug_printf_exec("run_pipe return %d\n", rcode); + return rcode; } - - /* put our child in the process group whose leader is the - first process in this pipe */ - if (pi->pgrp < 0) { - pi->pgrp = child->pid; +#if ENABLE_FEATURE_SH_STANDALONE + i = find_applet_by_name(argv_expanded[0]); + if (i >= 0 && APPLET_IS_NOFORK(i)) { + rcode = setup_redirects(command, squirrel); + if (rcode == 0) { + new_env = expand_assignments(argv, command->assignment_cnt); + old_vars = set_vars_and_save_old(new_env); + debug_printf_exec(": run_nofork_applet '%s' '%s'...\n", + argv_expanded[0], argv_expanded[1]); + rcode = run_nofork_applet(i, argv_expanded); + } + goto clean_up_and_ret; } - /* Don't check for errors. The child may be dead already, - * in which case setpgid returns error code EACCES. */ - setpgid(child->pid, pi->pgrp); +#endif + /* It is neither builtin nor applet. We must fork. */ + } - if (nextin != 0) - close(nextin); - if (nextout != 1) - close(nextout); + must_fork: + /* NB: argv_expanded may already be created, and that + * might include `cmd` runs! Do not rerun it! We *must* + * use argv_expanded if it's non-NULL */ - /* If there isn't another process, nextin is garbage - but it doesn't matter */ - nextin = pipefds[0]; - } - return -1; -} + /* Going to fork a child per each pipe member */ + pi->alive_cmds = 0; + nextin = 0; -static int run_list_real(struct pipe *pi) -{ - char *save_name = NULL; - char **list = NULL; - char **save_list = NULL; - struct pipe *rpipe; - int flag_rep = 0; - int save_num_progs; - int rcode=0, flag_skip=1; - int flag_restore = 0; - int if_code=0, next_if_code=0; /* need double-buffer to handle elif */ - reserved_style rmode, skip_more_in_this_rmode=RES_XXXX; - /* check syntax for "for" */ - for (rpipe = pi; rpipe; rpipe = rpipe->next) { - if ((rpipe->r_mode == RES_IN || - rpipe->r_mode == RES_FOR) && - (rpipe->next == NULL)) { - syntax(); - return 1; - } - if ((rpipe->r_mode == RES_IN && - (rpipe->next->r_mode == RES_IN && - rpipe->next->progs->argv != NULL))|| - (rpipe->r_mode == RES_FOR && - rpipe->next->r_mode != RES_IN)) { - syntax(); - return 1; + for (i = 0; i < pi->num_cmds; i++) { + struct fd_pair pipefds; +#if !BB_MMU + volatile nommu_save_t nommu_save; + nommu_save.new_env = NULL; + nommu_save.old_vars = NULL; + nommu_save.argv = NULL; + nommu_save.argv_from_re_execing = NULL; +#endif + command = &(pi->cmds[i]); + if (command->argv) { + debug_printf_exec(": pipe member '%s' '%s'...\n", + command->argv[0], command->argv[1]); + } else { + debug_printf_exec(": pipe member with no argv\n"); } - } - for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) { - if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL || - pi->r_mode == RES_FOR) { - flag_restore = 0; - if (!rpipe) { - flag_rep = 0; - rpipe = pi; + + /* pipes are inserted between pairs of commands */ + pipefds.rd = 0; + pipefds.wr = 1; + if ((i + 1) < pi->num_cmds) + xpiped_pair(pipefds); + + command->pid = BB_MMU ? fork() : vfork(); + if (!command->pid) { /* child */ +#if ENABLE_HUSH_JOB + disable_restore_tty_pgrp_on_exit(); + + /* Every child adds itself to new process group + * with pgid == pid_of_first_child_in_pipe */ + if (G.run_list_level == 1 && G_interactive_fd) { + pid_t pgrp; + pgrp = pi->pgrp; + if (pgrp < 0) /* true for 1st process only */ + pgrp = getpid(); + if (setpgid(0, pgrp) == 0 + && pi->followup != PIPE_BG + && G_saved_tty_pgrp /* we have ctty */ + ) { + /* We do it in *every* child, not just first, + * to avoid races */ + tcsetpgrp(G_interactive_fd, pgrp); } - } - rmode = pi->r_mode; - debug_printf("rmode=%d if_code=%d next_if_code=%d skip_more=%d\n", rmode, if_code, next_if_code, skip_more_in_this_rmode); - if (rmode == skip_more_in_this_rmode && flag_skip) { - if (pi->followup == PIPE_SEQ) flag_skip=0; - continue; - } - flag_skip = 1; - skip_more_in_this_rmode = RES_XXXX; - if (rmode == RES_THEN || rmode == RES_ELSE) if_code = next_if_code; - if (rmode == RES_THEN && if_code) continue; - if (rmode == RES_ELSE && !if_code) continue; - if (rmode == RES_ELIF && !if_code) continue; - if (rmode == RES_FOR && pi->num_progs) { - if (!list) { - /* if no variable values after "in" we skip "for" */ - if (!pi->next->progs->argv) continue; - /* create list of variable values */ - list = make_list_in(pi->next->progs->argv, - pi->progs->argv[0]); - save_list = list; - save_name = pi->progs->argv[0]; - pi->progs->argv[0] = NULL; - flag_rep = 1; - } - if (!(*list)) { - free(pi->progs->argv[0]); - free(save_list); - list = NULL; - flag_rep = 0; - pi->progs->argv[0] = save_name; - pi->progs->glob_result.gl_pathv[0] = - pi->progs->argv[0]; - continue; - } else { - /* insert new value from list for variable */ - if (pi->progs->argv[0]) - free(pi->progs->argv[0]); - pi->progs->argv[0] = *list++; - pi->progs->glob_result.gl_pathv[0] = - pi->progs->argv[0]; - } - } - if (rmode == RES_IN) continue; - if (rmode == RES_DO) { - if (!flag_rep) continue; - } - if ((rmode == RES_DONE)) { - if (flag_rep) { - flag_restore = 1; - } else { - rpipe = NULL; - } - } - if (pi->num_progs == 0) continue; - save_num_progs = pi->num_progs; /* save number of programs */ - rcode = run_pipe_real(pi); - debug_printf("run_pipe_real returned %d\n",rcode); - if (rcode!=-1) { - /* We only ran a builtin: rcode was set by the return value - * of run_pipe_real(), and we don't need to wait for anything. */ - } else if (pi->followup==PIPE_BG) { - /* XXX check bash's behavior with nontrivial pipes */ - /* XXX compute jobid */ - /* XXX what does bash do with attempts to background builtins? */ - insert_bg_job(pi); - rcode = EXIT_SUCCESS; - } else { - if (interactive) { - /* move the new process group into the foreground */ - if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY) - bb_perror_msg("tcsetpgrp-3"); - rcode = checkjobs(pi); - /* move the shell to the foreground */ - if (tcsetpgrp(shell_terminal, getpgid(0)) && errno != ENOTTY) - bb_perror_msg("tcsetpgrp-4"); + } +#endif + if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) { + /* 1st cmd in backgrounded pipe + * should have its stdin /dev/null'ed */ + close(0); + if (open(bb_dev_null, O_RDONLY)) + xopen("/", O_RDONLY); } else { - rcode = checkjobs(pi); - } - debug_printf("checkjobs returned %d\n",rcode); - } - last_return_code=rcode; - pi->num_progs = save_num_progs; /* restore number of programs */ - if ( rmode == RES_IF || rmode == RES_ELIF ) - next_if_code=rcode; /* can be overwritten a number of times */ - if (rmode == RES_WHILE) - flag_rep = !last_return_code; - if (rmode == RES_UNTIL) - flag_rep = last_return_code; - if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) || - (rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) ) - skip_more_in_this_rmode=rmode; - checkjobs(NULL); - } - return rcode; -} + xmove_fd(nextin, 0); + } + xmove_fd(pipefds.wr, 1); + if (pipefds.rd > 1) + close(pipefds.rd); + /* Like bash, explicit redirects override pipes, + * and the pipe fd is available for dup'ing. */ + if (setup_redirects(command, NULL)) + _exit(1); -/* broken, of course, but OK for testing */ -static char *indenter(int i) -{ - static char blanks[]=" "; - return &blanks[sizeof(blanks)-i-1]; -} + /* Restore default handlers just prior to exec */ + /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */ -/* return code is the exit status of the pipe */ -static int free_pipe(struct pipe *pi, int indent) -{ - char **p; - struct child_prog *child; - struct redir_struct *r, *rnext; - int a, i, ret_code=0; - char *ind = indenter(indent); - - if (pi->stopped_progs > 0) - return ret_code; - final_printf("%s run pipe: (pid %d)\n",ind,getpid()); - for (i=0; i<pi->num_progs; i++) { - child = &pi->progs[i]; - final_printf("%s command %d:\n",ind,i); - if (child->argv) { - for (a=0,p=child->argv; *p; a++,p++) { - final_printf("%s argv[%d] = %s\n",ind,a,*p); - } - globfree(&child->glob_result); - child->argv=NULL; - } else if (child->group) { - final_printf("%s begin group (subshell:%d)\n",ind, child->subshell); - ret_code = free_pipe_list(child->group,indent+3); - final_printf("%s end group\n",ind); + /* Stores to nommu_save list of env vars putenv'ed + * (NOMMU, on MMU we don't need that) */ + /* cast away volatility... */ + pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded); + /* pseudo_exec() does not return */ + } + + /* parent or error */ +#if ENABLE_HUSH_FAST + G.count_SIGCHLD++; +//bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD); +#endif + enable_restore_tty_pgrp_on_exit(); +#if !BB_MMU + /* Clean up after vforked child */ + free(nommu_save.argv); + free(nommu_save.argv_from_re_execing); + unset_vars(nommu_save.new_env); + add_vars(nommu_save.old_vars); +#endif + free(argv_expanded); + argv_expanded = NULL; + if (command->pid < 0) { /* [v]fork failed */ + /* Clearly indicate, was it fork or vfork */ + bb_perror_msg(BB_MMU ? "fork" : "vfork"); } else { - final_printf("%s (nil)\n",ind); - } - for (r=child->redirects; r; r=rnext) { - final_printf("%s redirect %d%s", ind, r->fd, redir_table[r->type].descrip); - if (r->dup == -1) { - /* guard against the case >$FOO, where foo is unset or blank */ - if (r->word.gl_pathv) { - final_printf(" %s\n", *r->word.gl_pathv); - globfree(&r->word); - } - } else { - final_printf("&%d\n", r->dup); - } - rnext=r->next; - free(r); + pi->alive_cmds++; +#if ENABLE_HUSH_JOB + /* Second and next children need to know pid of first one */ + if (pi->pgrp < 0) + pi->pgrp = command->pid; +#endif } - child->redirects=NULL; + + if (i) + close(nextin); + if ((i + 1) < pi->num_cmds) + close(pipefds.wr); + /* Pass read (output) pipe end to next iteration */ + nextin = pipefds.rd; } - free(pi->progs); /* children are an array, they get freed all at once */ - pi->progs=NULL; - return ret_code; -} -static int free_pipe_list(struct pipe *head, int indent) -{ - int rcode=0; /* if list has no members */ - struct pipe *pi, *next; - char *ind = indenter(indent); - for (pi=head; pi; pi=next) { - final_printf("%s pipe reserved mode %d\n", ind, pi->r_mode); - rcode = free_pipe(pi, indent); - final_printf("%s pipe followup code %d\n", ind, pi->followup); - next=pi->next; - pi->next=NULL; - free(pi); + if (!pi->alive_cmds) { + debug_leave(); + debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n"); + return 1; } - return rcode; -} -/* Select which version we will use */ -static int run_list(struct pipe *pi) -{ - int rcode=0; - if (fake_mode==0) { - rcode = run_list_real(pi); - } - /* free_pipe_list has the side effect of clearing memory - * In the long run that function can be merged with run_list_real, - * but doing that now would hobble the debugging effort. */ - free_pipe_list(pi,0); - return rcode; + debug_leave(); + debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds); + return -1; } -/* The API for glob is arguably broken. This routine pushes a non-matching - * string into the output structure, removing non-backslashed backslashes. - * If someone can prove me wrong, by performing this function within the - * original glob(3) api, feel free to rewrite this routine into oblivion. - * Return code (0 vs. GLOB_NOSPACE) matches glob(3). - * XXX broken if the last character is '\\', check that before calling. - */ -static int globhack(const char *src, int flags, glob_t *pglob) +#ifndef debug_print_tree +static void debug_print_tree(struct pipe *pi, int lvl) { - int cnt=0, pathc; - const char *s; - char *dest; - for (cnt=1, s=src; s && *s; s++) { - if (*s == '\\') s++; - cnt++; - } - dest = malloc(cnt); - if (!dest) return GLOB_NOSPACE; - if (!(flags & GLOB_APPEND)) { - pglob->gl_pathv=NULL; - pglob->gl_pathc=0; - pglob->gl_offs=0; - pglob->gl_offs=0; - } - pathc = ++pglob->gl_pathc; - pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv)); - if (pglob->gl_pathv == NULL) return GLOB_NOSPACE; - pglob->gl_pathv[pathc-1]=dest; - pglob->gl_pathv[pathc]=NULL; - for (s=src; s && *s; s++, dest++) { - if (*s == '\\') s++; - *dest = *s; - } - *dest='\0'; - return 0; -} + static const char *const PIPE[] = { + [PIPE_SEQ] = "SEQ", + [PIPE_AND] = "AND", + [PIPE_OR ] = "OR" , + [PIPE_BG ] = "BG" , + }; + static const char *RES[] = { + [RES_NONE ] = "NONE" , +#if ENABLE_HUSH_IF + [RES_IF ] = "IF" , + [RES_THEN ] = "THEN" , + [RES_ELIF ] = "ELIF" , + [RES_ELSE ] = "ELSE" , + [RES_FI ] = "FI" , +#endif +#if ENABLE_HUSH_LOOPS + [RES_FOR ] = "FOR" , + [RES_WHILE] = "WHILE", + [RES_UNTIL] = "UNTIL", + [RES_DO ] = "DO" , + [RES_DONE ] = "DONE" , +#endif +#if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE + [RES_IN ] = "IN" , +#endif +#if ENABLE_HUSH_CASE + [RES_CASE ] = "CASE" , + [RES_CASE_IN ] = "CASE_IN" , + [RES_MATCH] = "MATCH", + [RES_CASE_BODY] = "CASE_BODY", + [RES_ESAC ] = "ESAC" , +#endif + [RES_XXXX ] = "XXXX" , + [RES_SNTX ] = "SNTX" , + }; + static const char *const GRPTYPE[] = { + "{}", + "()", +#if ENABLE_HUSH_FUNCTIONS + "func()", +#endif + }; -/* XXX broken if the last character is '\\', check that before calling */ -static int glob_needed(const char *s) -{ - for (; *s; s++) { - if (*s == '\\') s++; - if (strchr("*[?",*s)) return 1; + int pin, prn; + + pin = 0; + while (pi) { + fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "", + pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]); + prn = 0; + while (prn < pi->num_cmds) { + struct command *command = &pi->cmds[prn]; + char **argv = command->argv; + + fprintf(stderr, "%*s cmd %d assignment_cnt:%d", + lvl*2, "", prn, + command->assignment_cnt); + if (command->group) { + fprintf(stderr, " group %s: (argv=%p)\n", + GRPTYPE[command->grp_type], + argv); + debug_print_tree(command->group, lvl+1); + prn++; + continue; + } + if (argv) while (*argv) { + fprintf(stderr, " '%s'", *argv); + argv++; + } + fprintf(stderr, "\n"); + prn++; + } + pi = pi->next; + pin++; } - return 0; } +#endif -#if 0 -static void globprint(glob_t *pglob) +/* NB: called by pseudo_exec, and therefore must not modify any + * global data until exec/_exit (we can be a child after vfork!) */ +static int run_list(struct pipe *pi) { - int i; - debug_printf("glob_t at %p:\n", pglob); - debug_printf(" gl_pathc=%d gl_pathv=%p gl_offs=%d gl_flags=%d\n", - pglob->gl_pathc, pglob->gl_pathv, pglob->gl_offs, pglob->gl_flags); - for (i=0; i<pglob->gl_pathc; i++) - debug_printf("pglob->gl_pathv[%d] = %p = %s\n", i, - pglob->gl_pathv[i], pglob->gl_pathv[i]); -} +#if ENABLE_HUSH_CASE + char *case_word = NULL; +#endif +#if ENABLE_HUSH_LOOPS + struct pipe *loop_top = NULL; + char **for_lcur = NULL; + char **for_list = NULL; +#endif + smallint last_followup; + smalluint rcode; +#if ENABLE_HUSH_IF || ENABLE_HUSH_CASE + smalluint cond_code = 0; +#else + enum { cond_code = 0 }; +#endif +#if HAS_KEYWORDS + smallint rword; /* enum reserved_style */ + smallint last_rword; /* ditto */ #endif -static int xglob(o_string *dest, int flags, glob_t *pglob) -{ - int gr; + debug_printf_exec("run_list start lvl %d\n", G.run_list_level); + debug_enter(); - /* short-circuit for null word */ - /* we can code this better when the debug_printf's are gone */ - if (dest->length == 0) { - if (dest->nonnull) { - /* bash man page calls this an "explicit" null */ - gr = globhack(dest->data, flags, pglob); - debug_printf("globhack returned %d\n",gr); - } else { - return 0; +#if ENABLE_HUSH_LOOPS + /* Check syntax for "for" */ + for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) { + if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN) + continue; + /* current word is FOR or IN (BOLD in comments below) */ + if (cpipe->next == NULL) { + syntax_error("malformed for"); + debug_leave(); + debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level); + return 1; } - } else if (glob_needed(dest->data)) { - gr = glob(dest->data, flags, NULL, pglob); - debug_printf("glob returned %d\n",gr); - if (gr == GLOB_NOMATCH) { - /* quote removal, or more accurately, backslash removal */ - gr = globhack(dest->data, flags, pglob); - debug_printf("globhack returned %d\n",gr); + /* "FOR v; do ..." and "for v IN a b; do..." are ok */ + if (cpipe->next->res_word == RES_DO) + continue; + /* next word is not "do". It must be "in" then ("FOR v in ...") */ + if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */ + || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */ + ) { + syntax_error("malformed for"); + debug_leave(); + debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level); + return 1; } - } else { - gr = globhack(dest->data, flags, pglob); - debug_printf("globhack returned %d\n",gr); } - if (gr == GLOB_NOSPACE) - bb_error_msg_and_die("out of memory during glob"); - if (gr != 0) { /* GLOB_ABORTED ? */ - bb_error_msg("glob(3) error %d",gr); - } - /* globprint(glob_target); */ - return gr; -} - -/* This is used to get/check local shell variables */ -static char *get_local_var(const char *s) -{ - struct variables *cur; - - if (!s) - return NULL; - for (cur = top_vars; cur; cur=cur->next) - if(strcmp(cur->name, s)==0) - return cur->value; - return NULL; -} +#endif -/* This is used to set local shell variables - flg_export==0 if only local (not exporting) variable - flg_export==1 if "new" exporting environ - flg_export>1 if current startup environ (not call putenv()) */ -static int set_local_var(const char *s, int flg_export) -{ - char *name, *value; - int result=0; - struct variables *cur; + /* Past this point, all code paths should jump to ret: label + * in order to return, no direct "return" statements please. + * This helps to ensure that no memory is leaked. */ - name=strdup(s); +#if ENABLE_HUSH_JOB + G.run_list_level++; +#endif - /* Assume when we enter this function that we are already in - * NAME=VALUE format. So the first order of business is to - * split 's' on the '=' into 'name' and 'value' */ - value = strchr(name, '='); - if (value==0 && ++value==0) { - free(name); - return -1; - } - *value++ = 0; +#if HAS_KEYWORDS + rword = RES_NONE; + last_rword = RES_XXXX; +#endif + last_followup = PIPE_SEQ; + rcode = G.last_exitcode; - for(cur = top_vars; cur; cur = cur->next) { - if(strcmp(cur->name, name)==0) + /* Go through list of pipes, (maybe) executing them. */ + for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) { + if (G.flag_SIGINT) break; - } - if(cur) { - if(strcmp(cur->value, value)==0) { - if(flg_export>0 && cur->flg_export==0) - cur->flg_export=flg_export; - else - result++; - } else { - if(cur->flg_read_only) { - bb_error_msg("%s: readonly variable", name); - result = -1; - } else { - if(flg_export>0 || cur->flg_export>1) - cur->flg_export=1; - free(cur->value); - - cur->value = strdup(value); + IF_HAS_KEYWORDS(rword = pi->res_word;) + debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n", + rword, cond_code, last_rword); +#if ENABLE_HUSH_LOOPS + if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR) + && loop_top == NULL /* avoid bumping G.depth_of_loop twice */ + ) { + /* start of a loop: remember where loop starts */ + loop_top = pi; + G.depth_of_loop++; + } +#endif + /* Still in the same "if...", "then..." or "do..." branch? */ + if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) { + if ((rcode == 0 && last_followup == PIPE_OR) + || (rcode != 0 && last_followup == PIPE_AND) + ) { + /* It is "<true> || CMD" or "<false> && CMD" + * and we should not execute CMD */ + debug_printf_exec("skipped cmd because of || or &&\n"); + last_followup = pi->followup; + continue; } } - } else { - cur = malloc(sizeof(struct variables)); - if(!cur) { - result = -1; + last_followup = pi->followup; + IF_HAS_KEYWORDS(last_rword = rword;) +#if ENABLE_HUSH_IF + if (cond_code) { + if (rword == RES_THEN) { + /* if false; then ... fi has exitcode 0! */ + G.last_exitcode = rcode = EXIT_SUCCESS; + /* "if <false> THEN cmd": skip cmd */ + continue; + } } else { - cur->name = strdup(name); - if(cur->name == 0) { - free(cur); - result = -1; - } else { - struct variables *bottom = top_vars; - cur->value = strdup(value); - cur->next = 0; - cur->flg_export = flg_export; - cur->flg_read_only = 0; - while(bottom->next) bottom=bottom->next; - bottom->next = cur; + if (rword == RES_ELSE || rword == RES_ELIF) { + /* "if <true> then ... ELSE/ELIF cmd": + * skip cmd and all following ones */ + break; } } - } - - if(result==0 && cur->flg_export==1) { - *(value-1) = '='; - result = putenv(name); - } else { - free(name); - if(result>0) /* equivalent to previous set */ - result = 0; - } - return result; -} - -static void unset_local_var(const char *name) -{ - struct variables *cur; +#endif +#if ENABLE_HUSH_LOOPS + if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */ + if (!for_lcur) { + /* first loop through for */ + + static const char encoded_dollar_at[] ALIGN1 = { + SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0' + }; /* encoded representation of "$@" */ + static const char *const encoded_dollar_at_argv[] = { + encoded_dollar_at, NULL + }; /* argv list with one element: "$@" */ + char **vals; + + vals = (char**)encoded_dollar_at_argv; + if (pi->next->res_word == RES_IN) { + /* if no variable values after "in" we skip "for" */ + if (!pi->next->cmds[0].argv) { + G.last_exitcode = rcode = EXIT_SUCCESS; + debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n"); + break; + } + vals = pi->next->cmds[0].argv; + } /* else: "for var; do..." -> assume "$@" list */ + /* create list of variable values */ + debug_print_strings("for_list made from", vals); + for_list = expand_strvec_to_strvec(vals); + for_lcur = for_list; + debug_print_strings("for_list", for_list); + } + if (!*for_lcur) { + /* "for" loop is over, clean up */ + free(for_list); + for_list = NULL; + for_lcur = NULL; + break; + } + /* Insert next value from for_lcur */ + /* note: *for_lcur already has quotes removed, $var expanded, etc */ + set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), 0, 0); + continue; + } + if (rword == RES_IN) { + continue; /* "for v IN list;..." - "in" has no cmds anyway */ + } + if (rword == RES_DONE) { + continue; /* "done" has no cmds too */ + } +#endif +#if ENABLE_HUSH_CASE + if (rword == RES_CASE) { + case_word = expand_strvec_to_string(pi->cmds->argv); + continue; + } + if (rword == RES_MATCH) { + char **argv; - if (name) { - for (cur = top_vars; cur; cur=cur->next) { - if(strcmp(cur->name, name)==0) + if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */ break; + /* all prev words didn't match, does this one match? */ + argv = pi->cmds->argv; + while (*argv) { + char *pattern = expand_string_to_string(*argv); + /* TODO: which FNM_xxx flags to use? */ + cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0); + free(pattern); + if (cond_code == 0) { /* match! we will execute this branch */ + free(case_word); /* make future "word)" stop */ + case_word = NULL; + break; + } + argv++; + } + continue; } - if(cur!=0) { - struct variables *next = top_vars; - if(cur->flg_read_only) { - bb_error_msg("%s: readonly variable", name); - return; + if (rword == RES_CASE_BODY) { /* inside of a case branch */ + if (cond_code != 0) + continue; /* not matched yet, skip this pipe */ + } +#endif + /* Just pressing <enter> in shell should check for jobs. + * OTOH, in non-interactive shell this is useless + * and only leads to extra job checks */ + if (pi->num_cmds == 0) { + if (G_interactive_fd) + goto check_jobs_and_continue; + continue; + } + + /* After analyzing all keywords and conditions, we decided + * to execute this pipe. NB: have to do checkjobs(NULL) + * after run_pipe to collect any background children, + * even if list execution is to be stopped. */ + debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds); + { + int r; +#if ENABLE_HUSH_LOOPS + G.flag_break_continue = 0; +#endif + rcode = r = run_pipe(pi); /* NB: rcode is a smallint */ + if (r != -1) { + /* We ran a builtin, function, or group. + * rcode is already known + * and we don't need to wait for anything. */ + G.last_exitcode = rcode; + debug_printf_exec(": builtin/func exitcode %d\n", rcode); + check_and_run_traps(0); +#if ENABLE_HUSH_LOOPS + /* Was it "break" or "continue"? */ + if (G.flag_break_continue) { + smallint fbc = G.flag_break_continue; + /* We might fall into outer *loop*, + * don't want to break it too */ + if (loop_top) { + G.depth_break_continue--; + if (G.depth_break_continue == 0) + G.flag_break_continue = 0; + /* else: e.g. "continue 2" should *break* once, *then* continue */ + } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */ + if (G.depth_break_continue != 0 || fbc == BC_BREAK) + goto check_jobs_and_break; + /* "continue": simulate end of loop */ + rword = RES_DONE; + continue; + } +#endif +#if ENABLE_HUSH_FUNCTIONS + if (G.flag_return_in_progress == 1) { + /* same as "goto check_jobs_and_break" */ + checkjobs(NULL); + break; + } +#endif + } else if (pi->followup == PIPE_BG) { + /* What does bash do with attempts to background builtins? */ + /* even bash 3.2 doesn't do that well with nested bg: + * try "{ { sleep 10; echo DEEP; } & echo HERE; } &". + * I'm NOT treating inner &'s as jobs */ + check_and_run_traps(0); +#if ENABLE_HUSH_JOB + if (G.run_list_level == 1) + insert_bg_job(pi); +#endif + G.last_exitcode = rcode = EXIT_SUCCESS; + debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n"); } else { - if(cur->flg_export) - unsetenv(cur->name); - free(cur->name); - free(cur->value); - while (next->next != cur) - next = next->next; - next->next = cur->next; +#if ENABLE_HUSH_JOB + if (G.run_list_level == 1 && G_interactive_fd) { + /* Waits for completion, then fg's main shell */ + rcode = checkjobs_and_fg_shell(pi); + debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode); + check_and_run_traps(0); + } else +#endif + { /* This one just waits for completion */ + rcode = checkjobs(pi); + debug_printf_exec(": checkjobs exitcode %d\n", rcode); + check_and_run_traps(0); + } + G.last_exitcode = rcode; } - free(cur); } - } + + /* Analyze how result affects subsequent commands */ +#if ENABLE_HUSH_IF + if (rword == RES_IF || rword == RES_ELIF) + cond_code = rcode; +#endif +#if ENABLE_HUSH_LOOPS + /* Beware of "while false; true; do ..."! */ + if (pi->next && pi->next->res_word == RES_DO) { + if (rword == RES_WHILE) { + if (rcode) { + /* "while false; do...done" - exitcode 0 */ + G.last_exitcode = rcode = EXIT_SUCCESS; + debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n"); + goto check_jobs_and_break; + } + } + if (rword == RES_UNTIL) { + if (!rcode) { + debug_printf_exec(": until expr is true: breaking\n"); + check_jobs_and_break: + checkjobs(NULL); + break; + } + } + } +#endif + + check_jobs_and_continue: + checkjobs(NULL); + } /* for (pi) */ + +#if ENABLE_HUSH_JOB + G.run_list_level--; +#endif +#if ENABLE_HUSH_LOOPS + if (loop_top) + G.depth_of_loop--; + free(for_list); +#endif +#if ENABLE_HUSH_CASE + free(case_word); +#endif + debug_leave(); + debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode); + return rcode; } -static int is_assignment(const char *s) +/* Select which version we will use */ +static int run_and_free_list(struct pipe *pi) { - if (s==NULL || !isalpha(*s)) return 0; - ++s; - while(isalnum(*s) || *s=='_') ++s; - return *s=='='; + int rcode = 0; + debug_printf_exec("run_and_free_list entered\n"); + if (!G.fake_mode) { + debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds); + rcode = run_list(pi); + } + /* free_pipe_list has the side effect of clearing memory. + * In the long run that function can be merged with run_list, + * but doing that now would hobble the debugging effort. */ + free_pipe_list(pi); + debug_printf_exec("run_and_free_list return %d\n", rcode); + return rcode; } -/* the src parameter allows us to peek forward to a possible &n syntax - * for file descriptor duplication, e.g., "2>&1". - * Return code is 0 normally, 1 if a syntax error is detected in src. - * Resource errors (in xmalloc) cause the process to exit */ -static int setup_redirect(struct p_context *ctx, int fd, redir_type style, - struct in_str *input) + +static struct pipe *new_pipe(void) { - struct child_prog *child=ctx->child; - struct redir_struct *redir = child->redirects; - struct redir_struct *last_redir=NULL; + struct pipe *pi; + pi = xzalloc(sizeof(struct pipe)); + /*pi->followup = 0; - deliberately invalid value */ + /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */ + return pi; +} - /* Create a new redir_struct and drop it onto the end of the linked list */ - while(redir) { - last_redir=redir; - redir=redir->next; - } - redir = xmalloc(sizeof(struct redir_struct)); - redir->next=NULL; - redir->word.gl_pathv=NULL; - if (last_redir) { - last_redir->next=redir; +/* Command (member of a pipe) is complete, or we start a new pipe + * if ctx->command is NULL. + * No errors possible here. + */ +static int done_command(struct parse_context *ctx) +{ + /* The command is really already in the pipe structure, so + * advance the pipe counter and make a new, null command. */ + struct pipe *pi = ctx->pipe; + struct command *command = ctx->command; + + if (command) { + if (IS_NULL_CMD(command)) { + debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds); + goto clear_and_ret; + } + pi->num_cmds++; + debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds); + //debug_print_tree(ctx->list_head, 20); } else { - child->redirects=redir; + debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds); } - redir->type=style; - redir->fd= (fd==-1) ? redir_table[style].default_fd : fd ; + /* Only real trickiness here is that the uncommitted + * command structure is not counted in pi->num_cmds. */ + pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1)); + ctx->command = command = &pi->cmds[pi->num_cmds]; + clear_and_ret: + memset(command, 0, sizeof(*command)); + return pi->num_cmds; /* used only for 0/nonzero check */ +} - debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip); +static void done_pipe(struct parse_context *ctx, pipe_style type) +{ + int not_null; - /* Check for a '2>&1' type redirect */ - redir->dup = redirect_dup_num(input); - if (redir->dup == -2) return 1; /* syntax error */ - if (redir->dup != -1) { - /* Erik had a check here that the file descriptor in question - * is legit; I postpone that to "run time" - * A "-" representation of "close me" shows up as a -3 here */ - debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup); - } else { - /* We do _not_ try to open the file that src points to, - * since we need to return and let src be expanded first. - * Set ctx->pending_redirect, so we know what to do at the - * end of the next parsed word. + debug_printf_parse("done_pipe entered, followup %d\n", type); + /* Close previous command */ + not_null = done_command(ctx); + ctx->pipe->followup = type; +#if HAS_KEYWORDS + ctx->pipe->pi_inverted = ctx->ctx_inverted; + ctx->ctx_inverted = 0; + ctx->pipe->res_word = ctx->ctx_res_w; +#endif + + /* Without this check, even just <enter> on command line generates + * tree of three NOPs (!). Which is harmless but annoying. + * IOW: it is safe to do it unconditionally. */ + if (not_null +#if ENABLE_HUSH_IF + || ctx->ctx_res_w == RES_FI +#endif +#if ENABLE_HUSH_LOOPS + || ctx->ctx_res_w == RES_DONE + || ctx->ctx_res_w == RES_FOR + || ctx->ctx_res_w == RES_IN +#endif +#if ENABLE_HUSH_CASE + || ctx->ctx_res_w == RES_ESAC +#endif + ) { + struct pipe *new_p; + debug_printf_parse("done_pipe: adding new pipe: " + "not_null:%d ctx->ctx_res_w:%d\n", + not_null, ctx->ctx_res_w); + new_p = new_pipe(); + ctx->pipe->next = new_p; + ctx->pipe = new_p; + /* RES_THEN, RES_DO etc are "sticky" - + * they remain set for pipes inside if/while. + * This is used to control execution. + * RES_FOR and RES_IN are NOT sticky (needed to support + * cases where variable or value happens to match a keyword): */ - ctx->pending_redirect = redir; +#if ENABLE_HUSH_LOOPS + if (ctx->ctx_res_w == RES_FOR + || ctx->ctx_res_w == RES_IN) + ctx->ctx_res_w = RES_NONE; +#endif +#if ENABLE_HUSH_CASE + if (ctx->ctx_res_w == RES_MATCH) + ctx->ctx_res_w = RES_CASE_BODY; + if (ctx->ctx_res_w == RES_CASE) + ctx->ctx_res_w = RES_CASE_IN; +#endif + ctx->command = NULL; /* trick done_command below */ + /* Create the memory for command, roughly: + * ctx->pipe->cmds = new struct command; + * ctx->command = &ctx->pipe->cmds[0]; + */ + done_command(ctx); + //debug_print_tree(ctx->list_head, 10); } - return 0; + debug_printf_parse("done_pipe return\n"); } -struct pipe *new_pipe(void) { - struct pipe *pi; - pi = xmalloc(sizeof(struct pipe)); - pi->num_progs = 0; - pi->progs = NULL; - pi->next = NULL; - pi->followup = 0; /* invalid */ - return pi; -} - -static void initialize_context(struct p_context *ctx) +static void initialize_context(struct parse_context *ctx) { - ctx->pipe=NULL; - ctx->pending_redirect=NULL; - ctx->child=NULL; - ctx->list_head=new_pipe(); - ctx->pipe=ctx->list_head; - ctx->w=RES_NONE; - ctx->stack=NULL; - ctx->old_flag=0; - done_command(ctx); /* creates the memory for working child */ + memset(ctx, 0, sizeof(*ctx)); + ctx->pipe = ctx->list_head = new_pipe(); + /* Create the memory for command, roughly: + * ctx->pipe->cmds = new struct command; + * ctx->command = &ctx->pipe->cmds[0]; + */ + done_command(ctx); } -/* normal return is 0 - * if a reserved word is found, and processed, return 1 - * should handle if, then, elif, else, fi, for, while, until, do, done. - * case, function, and select are obnoxious, save those for later. +/* If a reserved word is found and processed, parse context is modified + * and 1 is returned. */ -int reserved_word(o_string *dest, struct p_context *ctx) +#if HAS_KEYWORDS +struct reserved_combo { + char literal[6]; + unsigned char res; + unsigned char assignment_flag; + int flag; +}; +enum { + FLAG_END = (1 << RES_NONE ), +#if ENABLE_HUSH_IF + FLAG_IF = (1 << RES_IF ), + FLAG_THEN = (1 << RES_THEN ), + FLAG_ELIF = (1 << RES_ELIF ), + FLAG_ELSE = (1 << RES_ELSE ), + FLAG_FI = (1 << RES_FI ), +#endif +#if ENABLE_HUSH_LOOPS + FLAG_FOR = (1 << RES_FOR ), + FLAG_WHILE = (1 << RES_WHILE), + FLAG_UNTIL = (1 << RES_UNTIL), + FLAG_DO = (1 << RES_DO ), + FLAG_DONE = (1 << RES_DONE ), + FLAG_IN = (1 << RES_IN ), +#endif +#if ENABLE_HUSH_CASE + FLAG_MATCH = (1 << RES_MATCH), + FLAG_ESAC = (1 << RES_ESAC ), +#endif + FLAG_START = (1 << RES_XXXX ), +}; + +static const struct reserved_combo* match_reserved_word(o_string *word) { - struct reserved_combo { - char *literal; - int code; - long flag; - }; /* Mostly a list of accepted follow-up reserved words. * FLAG_END means we are done with the sequence, and are ready * to turn the compound list into a command. * FLAG_START means the word must start a new compound list. */ - static struct reserved_combo reserved_list[] = { - { "if", RES_IF, FLAG_THEN | FLAG_START }, - { "then", RES_THEN, FLAG_ELIF | FLAG_ELSE | FLAG_FI }, - { "elif", RES_ELIF, FLAG_THEN }, - { "else", RES_ELSE, FLAG_FI }, - { "fi", RES_FI, FLAG_END }, - { "for", RES_FOR, FLAG_IN | FLAG_START }, - { "while", RES_WHILE, FLAG_DO | FLAG_START }, - { "until", RES_UNTIL, FLAG_DO | FLAG_START }, - { "in", RES_IN, FLAG_DO }, - { "do", RES_DO, FLAG_DONE }, - { "done", RES_DONE, FLAG_END } + static const struct reserved_combo reserved_list[] = { +#if ENABLE_HUSH_IF + { "!", RES_NONE, NOT_ASSIGNMENT , 0 }, + { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START }, + { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI }, + { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN }, + { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI }, + { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END }, +#endif +#if ENABLE_HUSH_LOOPS + { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START }, + { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START }, + { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START }, + { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO }, + { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE }, + { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END }, +#endif +#if ENABLE_HUSH_CASE + { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START }, + { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END }, +#endif }; - struct reserved_combo *r; - for (r=reserved_list; -#define NRES sizeof(reserved_list)/sizeof(struct reserved_combo) - r<reserved_list+NRES; r++) { - if (strcmp(dest->data, r->literal) == 0) { - debug_printf("found reserved word %s, code %d\n",r->literal,r->code); - if (r->flag & FLAG_START) { - struct p_context *new = xmalloc(sizeof(struct p_context)); - debug_printf("push stack\n"); - if (ctx->w == RES_IN || ctx->w == RES_FOR) { - syntax(); - free(new); - ctx->w = RES_SNTX; - b_reset(dest); - return 1; - } - *new = *ctx; /* physical copy */ - initialize_context(ctx); - ctx->stack=new; - } else if ( ctx->w == RES_NONE || ! (ctx->old_flag & (1<<r->code))) { - syntax(); - ctx->w = RES_SNTX; - b_reset(dest); - return 1; - } - ctx->w=r->code; - ctx->old_flag = r->flag; - if (ctx->old_flag & FLAG_END) { - struct p_context *old; - debug_printf("pop stack\n"); - done_pipe(ctx,PIPE_SEQ); - old = ctx->stack; - old->child->group = ctx->list_head; - old->child->subshell = 0; - *ctx = *old; /* physical copy */ - free(old); - } - b_reset (dest); - return 1; + const struct reserved_combo *r; + + for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) { + if (strcmp(word->data, r->literal) == 0) + return r; + } + return NULL; +} +/* Return 0: not a keyword, 1: keyword + */ +static int reserved_word(o_string *word, struct parse_context *ctx) +{ +#if ENABLE_HUSH_CASE + static const struct reserved_combo reserved_match = { + "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC + }; +#endif + const struct reserved_combo *r; + + if (word->o_quoted) + return 0; + r = match_reserved_word(word); + if (!r) + return 0; + + debug_printf("found reserved word %s, res %d\n", r->literal, r->res); +#if ENABLE_HUSH_CASE + if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) { + /* "case word IN ..." - IN part starts first MATCH part */ + r = &reserved_match; + } else +#endif + if (r->flag == 0) { /* '!' */ + if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */ + syntax_error("! ! command"); + ctx->ctx_res_w = RES_SNTX; } + ctx->ctx_inverted = 1; + return 1; } - return 0; + if (r->flag & FLAG_START) { + struct parse_context *old; + + old = xmalloc(sizeof(*old)); + debug_printf_parse("push stack %p\n", old); + *old = *ctx; /* physical copy */ + initialize_context(ctx); + ctx->stack = old; + } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) { + syntax_error_at(word->data); + ctx->ctx_res_w = RES_SNTX; + return 1; + } else { + /* "{...} fi" is ok. "{...} if" is not + * Example: + * if { echo foo; } then { echo bar; } fi */ + if (ctx->command->group) + done_pipe(ctx, PIPE_SEQ); + } + + ctx->ctx_res_w = r->res; + ctx->old_flag = r->flag; + word->o_assignment = r->assignment_flag; + + if (ctx->old_flag & FLAG_END) { + struct parse_context *old; + + done_pipe(ctx, PIPE_SEQ); + debug_printf_parse("pop stack %p\n", ctx->stack); + old = ctx->stack; + old->command->group = ctx->list_head; + old->command->grp_type = GRP_NORMAL; +#if !BB_MMU + o_addstr(&old->as_string, ctx->as_string.data); + o_free_unsafe(&ctx->as_string); + old->command->group_as_string = xstrdup(old->as_string.data); + debug_printf_parse("pop, remembering as:'%s'\n", + old->command->group_as_string); +#endif + *ctx = *old; /* physical copy */ + free(old); + } + return 1; } +#endif -/* normal return is 0. - * Syntax or xglob errors return 1. */ -static int done_word(o_string *dest, struct p_context *ctx) +/* Word is complete, look at it and update parsing context. + * Normal return is 0. Syntax errors return 1. + * Note: on return, word is reset, but not o_free'd! + */ +static int done_word(o_string *word, struct parse_context *ctx) { - struct child_prog *child=ctx->child; - glob_t *glob_target; - int gr, flags = 0; + struct command *command = ctx->command; - debug_printf("done_word: %s %p\n", dest->data, child); - if (dest->length == 0 && !dest->nonnull) { - debug_printf(" true null, ignored\n"); + debug_printf_parse("done_word entered: '%s' %p\n", word->data, command); + if (word->length == 0 && word->o_quoted == 0) { + debug_printf_parse("done_word return 0: true null, ignored\n"); return 0; } + if (ctx->pending_redirect) { - glob_target = &ctx->pending_redirect->word; + /* We do not glob in e.g. >*.tmp case. bash seems to glob here + * only if run as "bash", not "sh" */ + /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html + * "2.7 Redirection + * ...the word that follows the redirection operator + * shall be subjected to tilde expansion, parameter expansion, + * command substitution, arithmetic expansion, and quote + * removal. Pathname expansion shall not be performed + * on the word by a non-interactive shell; an interactive + * shell may perform it, but shall do so only when + * the expansion would result in one word." + */ + ctx->pending_redirect->rd_filename = xstrdup(word->data); + /* Cater for >\file case: + * >\a creates file a; >\\a, >"\a", >"\\a" create file \a + * Same with heredocs: + * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H + */ + if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) { + unbackslash(ctx->pending_redirect->rd_filename); + /* Is it <<"HEREDOC"? */ + if (word->o_quoted) { + ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED; + } + } + debug_printf_parse("word stored in rd_filename: '%s'\n", word->data); + ctx->pending_redirect = NULL; } else { - if (child->group) { - syntax(); - return 1; /* syntax error, groups and arglists don't mix */ + /* If this word wasn't an assignment, next ones definitely + * can't be assignments. Even if they look like ones. */ + if (word->o_assignment != DEFINITELY_ASSIGNMENT + && word->o_assignment != WORD_IS_KEYWORD + ) { + word->o_assignment = NOT_ASSIGNMENT; + } else { + if (word->o_assignment == DEFINITELY_ASSIGNMENT) + command->assignment_cnt++; + word->o_assignment = MAYBE_ASSIGNMENT; + } + +#if HAS_KEYWORDS +# if ENABLE_HUSH_CASE + if (ctx->ctx_dsemicolon + && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */ + ) { + /* already done when ctx_dsemicolon was set to 1: */ + /* ctx->ctx_res_w = RES_MATCH; */ + ctx->ctx_dsemicolon = 0; + } else +# endif + if (!command->argv /* if it's the first word... */ +# if ENABLE_HUSH_LOOPS + && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */ + && ctx->ctx_res_w != RES_IN +# endif +# if ENABLE_HUSH_CASE + && ctx->ctx_res_w != RES_CASE +# endif + ) { + debug_printf_parse("checking '%s' for reserved-ness\n", word->data); + if (reserved_word(word, ctx)) { + o_reset_to_empty_unquoted(word); + debug_printf_parse("done_word return %d\n", + (ctx->ctx_res_w == RES_SNTX)); + return (ctx->ctx_res_w == RES_SNTX); + } } - if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) { - debug_printf("checking %s for reserved-ness\n",dest->data); - if (reserved_word(dest,ctx)) return ctx->w==RES_SNTX; +#endif + if (command->group) { + /* "{ echo foo; } echo bar" - bad */ + syntax_error_at(word->data); + debug_printf_parse("done_word return 1: syntax error, " + "groups and arglists don't mix\n"); + return 1; } - glob_target = &child->glob_result; - if (child->argv) flags |= GLOB_APPEND; + if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */ + /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */ + && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL) + /* (otherwise it's known to be not empty and is already safe) */ + ) { + /* exclude "$@" - it can expand to no word despite "" */ + char *p = word->data; + while (p[0] == SPECIAL_VAR_SYMBOL + && (p[1] & 0x7f) == '@' + && p[2] == SPECIAL_VAR_SYMBOL + ) { + p += 3; + } + if (p == word->data || p[0] != '\0') { + /* saw no "$@", or not only "$@" but some + * real text is there too */ + /* insert "empty variable" reference, this makes + * e.g. "", $empty"" etc to not disappear */ + o_addchr(word, SPECIAL_VAR_SYMBOL); + o_addchr(word, SPECIAL_VAR_SYMBOL); + } + } + command->argv = add_string_to_strings(command->argv, xstrdup(word->data)); + debug_print_strings("word appended to argv", command->argv); } - gr = xglob(dest, flags, glob_target); - if (gr != 0) return 1; - b_reset(dest); - if (ctx->pending_redirect) { - ctx->pending_redirect=NULL; - if (glob_target->gl_pathc != 1) { - bb_error_msg("ambiguous redirect"); +#if ENABLE_HUSH_LOOPS + if (ctx->ctx_res_w == RES_FOR) { + if (word->o_quoted + || !is_well_formed_var_name(command->argv[0], '\0') + ) { + /* bash says just "not a valid identifier" */ + syntax_error("not a valid identifier in for"); return 1; } - } else { - child->argv = glob_target->gl_pathv; + /* Force FOR to have just one word (variable name) */ + /* NB: basically, this makes hush see "for v in ..." + * syntax as if it is "for v; in ...". FOR and IN become + * two pipe structs in parse tree. */ + done_pipe(ctx, PIPE_SEQ); } - if (ctx->w == RES_FOR) { - done_word(dest,ctx); - done_pipe(ctx,PIPE_SEQ); +#endif +#if ENABLE_HUSH_CASE + /* Force CASE to have just one word */ + if (ctx->ctx_res_w == RES_CASE) { + done_pipe(ctx, PIPE_SEQ); } - return 0; -} +#endif -/* The only possible error here is out of memory, in which case - * xmalloc exits. */ -static int done_command(struct p_context *ctx) -{ - /* The child is really already in the pipe structure, so - * advance the pipe counter and make a new, null child. - * Only real trickiness here is that the uncommitted - * child structure, to which ctx->child points, is not - * counted in pi->num_progs. */ - struct pipe *pi=ctx->pipe; - struct child_prog *prog=ctx->child; + o_reset_to_empty_unquoted(word); - if (prog && prog->group == NULL - && prog->argv == NULL - && prog->redirects == NULL) { - debug_printf("done_command: skipping null command\n"); - return 0; - } else if (prog) { - pi->num_progs++; - debug_printf("done_command: num_progs incremented to %d\n",pi->num_progs); - } else { - debug_printf("done_command: initializing\n"); - } - pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1)); - - prog = pi->progs + pi->num_progs; - prog->redirects = NULL; - prog->argv = NULL; - prog->is_stopped = 0; - prog->group = NULL; - prog->glob_result.gl_pathv = NULL; - prog->family = pi; - prog->sp = 0; - ctx->child = prog; - prog->type = ctx->type; - - /* but ctx->pipe and ctx->list_head remain unchanged */ + debug_printf_parse("done_word return 0\n"); return 0; } -static int done_pipe(struct p_context *ctx, pipe_style type) -{ - struct pipe *new_p; - done_command(ctx); /* implicit closure of previous command */ - debug_printf("done_pipe, type %d\n", type); - ctx->pipe->followup = type; - ctx->pipe->r_mode = ctx->w; - new_p=new_pipe(); - ctx->pipe->next = new_p; - ctx->pipe = new_p; - ctx->child = NULL; - done_command(ctx); /* set up new pipe to accept commands */ - return 0; -} -/* peek ahead in the in_str to find out if we have a "&n" construct, +/* Peek ahead in the input to find out if we have a "&n" construct, * as in "2>&1", that represents duplicating a file descriptor. - * returns either -2 (syntax error), -1 (no &), or the number found. + * Return: + * REDIRFD_CLOSE if >&- "close fd" construct is seen, + * REDIRFD_SYNTAX_ERR if syntax error, + * REDIRFD_TO_FILE if no & was seen, + * or the number found. */ -static int redirect_dup_num(struct in_str *input) +#if BB_MMU +#define parse_redir_right_fd(as_string, input) \ + parse_redir_right_fd(input) +#endif +static int parse_redir_right_fd(o_string *as_string, struct in_str *input) { - int ch, d=0, ok=0; - ch = b_peek(input); - if (ch != '&') return -1; + int ch, d, ok; + + ch = i_peek(input); + if (ch != '&') + return REDIRFD_TO_FILE; - b_getch(input); /* get the & */ - ch=b_peek(input); + ch = i_getch(input); /* get the & */ + nommu_addchr(as_string, ch); + ch = i_peek(input); if (ch == '-') { - b_getch(input); - return -3; /* "-" represents "close me" */ + ch = i_getch(input); + nommu_addchr(as_string, ch); + return REDIRFD_CLOSE; } - while (isdigit(ch)) { - d = d*10+(ch-'0'); - ok=1; - b_getch(input); - ch = b_peek(input); + d = 0; + ok = 0; + while (ch != EOF && isdigit(ch)) { + d = d*10 + (ch-'0'); + ok = 1; + ch = i_getch(input); + nommu_addchr(as_string, ch); + ch = i_peek(input); } if (ok) return d; +//TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2) + bb_error_msg("ambiguous redirect"); - return -2; + return REDIRFD_SYNTAX_ERR; +} + +/* Return code is 0 normal, 1 if a syntax error is detected + */ +static int parse_redirect(struct parse_context *ctx, + int fd, + redir_type style, + struct in_str *input) +{ + struct command *command = ctx->command; + struct redir_struct *redir; + struct redir_struct **redirp; + int dup_num; + + dup_num = REDIRFD_TO_FILE; + if (style != REDIRECT_HEREDOC) { + /* Check for a '>&1' type redirect */ + dup_num = parse_redir_right_fd(&ctx->as_string, input); + if (dup_num == REDIRFD_SYNTAX_ERR) + return 1; + } else { + int ch = i_peek(input); + dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */ + if (dup_num) { /* <<-... */ + ch = i_getch(input); + nommu_addchr(&ctx->as_string, ch); + ch = i_peek(input); + } + } + + if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) { + int ch = i_peek(input); + if (ch == '|') { + /* >|FILE redirect ("clobbering" >). + * Since we do not support "set -o noclobber" yet, + * >| and > are the same for now. Just eat |. + */ + ch = i_getch(input); + nommu_addchr(&ctx->as_string, ch); + } + } + + /* Create a new redir_struct and append it to the linked list */ + redirp = &command->redirects; + while ((redir = *redirp) != NULL) { + redirp = &(redir->next); + } + *redirp = redir = xzalloc(sizeof(*redir)); + /* redir->next = NULL; */ + /* redir->rd_filename = NULL; */ + redir->rd_type = style; + redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd; + + debug_printf_parse("redirect type %d %s\n", redir->rd_fd, + redir_table[style].descrip); + + redir->rd_dup = dup_num; + if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) { + /* Erik had a check here that the file descriptor in question + * is legit; I postpone that to "run time" + * A "-" representation of "close me" shows up as a -3 here */ + debug_printf_parse("duplicating redirect '%d>&%d'\n", + redir->rd_fd, redir->rd_dup); + } else { + /* Set ctx->pending_redirect, so we know what to do at the + * end of the next parsed word. */ + ctx->pending_redirect = redir; + } + return 0; } /* If a redirect is immediately preceded by a number, that number is @@ -2245,731 +4742,2506 @@ static int redirect_dup_num(struct in_str *input) * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo - * A -1 output from this program means no valid number was found, so the - * caller should use the appropriate default for this redirection. + * + * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html + * "2.7 Redirection + * ... If n is quoted, the number shall not be recognized as part of + * the redirection expression. For example: + * echo \2>a + * writes the character 2 into file a" + * We are getting it right by setting ->o_quoted on any \<char> + * + * A -1 return means no valid number was found, + * the caller should use the appropriate default for this redirection. */ static int redirect_opt_num(o_string *o) { int num; - if (o->length==0) return -1; - for(num=0; num<o->length; num++) { - if (!isdigit(*(o->data+num))) { - return -1; + if (o->data == NULL) + return -1; + num = bb_strtou(o->data, NULL, 10); + if (errno || num < 0) + return -1; + o_reset_to_empty_unquoted(o); + return num; +} + +#if BB_MMU +#define fetch_till_str(as_string, input, word, skip_tabs) \ + fetch_till_str(input, word, skip_tabs) +#endif +static char *fetch_till_str(o_string *as_string, + struct in_str *input, + const char *word, + int skip_tabs) +{ + o_string heredoc = NULL_O_STRING; + int past_EOL = 0; + int ch; + + goto jump_in; + while (1) { + ch = i_getch(input); + nommu_addchr(as_string, ch); + if (ch == '\n') { + if (strcmp(heredoc.data + past_EOL, word) == 0) { + heredoc.data[past_EOL] = '\0'; + debug_printf_parse("parsed heredoc '%s'\n", heredoc.data); + return heredoc.data; + } + do { + o_addchr(&heredoc, ch); + past_EOL = heredoc.length; + jump_in: + do { + ch = i_getch(input); + nommu_addchr(as_string, ch); + } while (skip_tabs && ch == '\t'); + } while (ch == '\n'); + } + if (ch == EOF) { + o_free_unsafe(&heredoc); + return NULL; } + o_addchr(&heredoc, ch); + nommu_addchr(as_string, ch); } - /* reuse num (and save an int) */ - num=atoi(o->data); - b_reset(o); - return num; } -FILE *generate_stream_from_list(struct pipe *head) +/* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs + * and load them all. There should be exactly heredoc_cnt of them. + */ +static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input) +{ + struct pipe *pi = ctx->list_head; + + while (pi && heredoc_cnt) { + int i; + struct command *cmd = pi->cmds; + + debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n", + pi->num_cmds, + cmd->argv ? cmd->argv[0] : "NONE"); + for (i = 0; i < pi->num_cmds; i++) { + struct redir_struct *redir = cmd->redirects; + + debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n", + i, cmd->argv ? cmd->argv[0] : "NONE"); + while (redir) { + if (redir->rd_type == REDIRECT_HEREDOC) { + char *p; + + redir->rd_type = REDIRECT_HEREDOC2; + /* redir->dup is (ab)used to indicate <<- */ + p = fetch_till_str(&ctx->as_string, input, + redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS); + if (!p) { + syntax_error("unexpected EOF in here document"); + return 1; + } + free(redir->rd_filename); + redir->rd_filename = p; + heredoc_cnt--; + } + redir = redir->next; + } + cmd++; + } + pi = pi->next; + } +#if 0 + /* Should be 0. If it isn't, it's a parse error */ + if (heredoc_cnt) + bb_error_msg_and_die("heredoc BUG 2"); +#endif + return 0; +} + + +#if ENABLE_HUSH_TICK +static FILE *generate_stream_from_string(const char *s) { FILE *pf; -#if 1 int pid, channel[2]; - if (pipe(channel)<0) bb_perror_msg_and_die("pipe"); -#if !defined(__UCLIBC__) || defined(__UCLIBC_HAS_MMU__) - pid=fork(); -#else - pid=vfork(); +#if !BB_MMU + char **to_free; #endif - if (pid<0) { - bb_perror_msg_and_die("fork"); - } else if (pid==0) { - close(channel[0]); - if (channel[1] != 1) { - dup2(channel[1],1); - close(channel[1]); - } -#if 0 -#define SURROGATE "surrogate response" - write(1,SURROGATE,sizeof(SURROGATE)); - _exit(run_list(head)); + + xpipe(channel); + pid = BB_MMU ? fork() : vfork(); + if (pid < 0) + bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork"); + + if (pid == 0) { /* child */ + disable_restore_tty_pgrp_on_exit(); + /* Process substitution is not considered to be usual + * 'command execution'. + * SUSv3 says ctrl-Z should be ignored, ctrl-C should not. + */ + bb_signals(0 + + (1 << SIGTSTP) + + (1 << SIGTTIN) + + (1 << SIGTTOU) + , SIG_IGN); + close(channel[0]); /* NB: close _first_, then move fd! */ + xmove_fd(channel[1], 1); + /* Prevent it from trying to handle ctrl-z etc */ + USE_HUSH_JOB(G.run_list_level = 1;) +#if BB_MMU + reset_traps_to_defaults(); + parse_and_run_string(s); + _exit(G.last_exitcode); #else - _exit(run_list_real(head)); /* leaks memory */ + /* We re-execute after vfork on NOMMU. This makes this script safe: + * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG + * huge=`cat BIG` # was blocking here forever + * echo OK + */ + re_execute_shell(&to_free, + s, + G.global_argv[0], + G.global_argv + 1); #endif } - debug_printf("forked child %d\n",pid); - close(channel[1]); - pf = fdopen(channel[0],"r"); - debug_printf("pipe on FILE *%p\n",pf); -#else - free_pipe_list(head,0); - pf=popen("echo surrogate response","r"); - debug_printf("started fake pipe on FILE *%p\n",pf); + + /* parent */ +#if ENABLE_HUSH_FAST + G.count_SIGCHLD++; +//bb_error_msg("[%d] fork in generate_stream_from_string: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD); +#endif + enable_restore_tty_pgrp_on_exit(); +#if !BB_MMU + free(to_free); #endif + close(channel[1]); + pf = fdopen(channel[0], "r"); return pf; } -/* this version hacked for testing purposes */ -/* return code is exit status of the process that is run. */ -static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end) +/* Return code is exit status of the process that is run. */ +static int process_command_subs(o_string *dest, const char *s) { - int retcode; - o_string result=NULL_O_STRING; - struct p_context inner; - FILE *p; + FILE *pf; struct in_str pipe_str; - initialize_context(&inner); - - /* recursion to generate command */ - retcode = parse_stream(&result, &inner, input, subst_end); - if (retcode != 0) return retcode; /* syntax error or EOF */ - done_word(&result, &inner); - done_pipe(&inner, PIPE_SEQ); - b_free(&result); - - p=generate_stream_from_list(inner.list_head); - if (p==NULL) return 1; - mark_open(fileno(p)); - setup_file_in_str(&pipe_str, p); - - /* now send results of command back into original context */ - retcode = parse_stream(dest, ctx, &pipe_str, '\0'); - /* XXX In case of a syntax error, should we try to kill the child? - * That would be tough to do right, so just read until EOF. */ - if (retcode == 1) { - while (b_getch(&pipe_str)!=EOF) { /* discard */ }; + int ch, eol_cnt; + + pf = generate_stream_from_string(s); + if (pf == NULL) + return 1; + close_on_exec_on(fileno(pf)); + + /* Now send results of command back into original context */ + setup_file_in_str(&pipe_str, pf); + eol_cnt = 0; + while ((ch = i_getch(&pipe_str)) != EOF) { + if (ch == '\n') { + eol_cnt++; + continue; + } + while (eol_cnt) { + o_addchr(dest, '\n'); + eol_cnt--; + } + o_addQchr(dest, ch); } debug_printf("done reading from pipe, pclose()ing\n"); - /* This is the step that wait()s for the child. Should be pretty - * safe, since we just read an EOF from its stdout. We could try - * to better, by using wait(), and keeping track of background jobs - * at the same time. That would be a lot of work, and contrary - * to the KISS philosophy of this program. */ - mark_closed(fileno(p)); - retcode=pclose(p); - free_pipe_list(inner.list_head,0); - debug_printf("pclosed, retcode=%d\n",retcode); - /* XXX this process fails to trim a single trailing newline */ - return retcode; -} - -static int parse_group(o_string *dest, struct p_context *ctx, + /* Note: we got EOF, and we just close the read end of the pipe. + * We do not wait for the `cmd` child to terminate. bash and ash do. + * Try these: + * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec + * `false`; echo $? - bash outputs "1" + */ + fclose(pf); + debug_printf("closed FILE from child. return 0\n"); + return 0; +} +#endif + +static int parse_group(o_string *dest, struct parse_context *ctx, struct in_str *input, int ch) { - int rcode, endch=0; - struct p_context sub; - struct child_prog *child = ctx->child; - if (child->argv) { - syntax(); - return 1; /* syntax error, groups and arglists don't mix */ - } - initialize_context(&sub); - switch(ch) { - case '(': endch=')'; child->subshell=1; break; - case '{': endch='}'; break; - default: syntax(); /* really logic error */ - } - rcode=parse_stream(dest,&sub,input,endch); - done_word(dest,&sub); /* finish off the final word in the subcontext */ - done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */ - child->group = sub.list_head; - return rcode; - /* child remains "open", available for possible redirects */ + /* dest contains characters seen prior to ( or {. + * Typically it's empty, but for function defs, + * it contains function name (without '()'). */ + struct pipe *pipe_list; + int endch; + struct command *command = ctx->command; + + debug_printf_parse("parse_group entered\n"); +#if ENABLE_HUSH_FUNCTIONS + if (ch == '(' && !dest->o_quoted) { + if (dest->length) + if (done_word(dest, ctx)) + return 1; + if (!command->argv) + goto skip; /* (... */ + if (command->argv[1]) { /* word word ... (... */ + syntax_error_unexpected_ch('('); + return 1; + } + /* it is "word(..." or "word (..." */ + do + ch = i_getch(input); + while (ch == ' ' || ch == '\t'); + if (ch != ')') { + syntax_error_unexpected_ch(ch); + return 1; + } + nommu_addchr(&ctx->as_string, ch); + do + ch = i_getch(input); + while (ch == ' ' || ch == '\t' || ch == '\n'); + if (ch != '{') { + syntax_error_unexpected_ch(ch); + return 1; + } + nommu_addchr(&ctx->as_string, ch); + command->grp_type = GRP_FUNCTION; + goto skip; + } +#endif + if (command->argv /* word [word]{... */ + || dest->length /* word{... */ + || dest->o_quoted /* ""{... */ + ) { + syntax_error(NULL); + debug_printf_parse("parse_group return 1: " + "syntax error, groups and arglists don't mix\n"); + return 1; + } + +#if ENABLE_HUSH_FUNCTIONS + skip: +#endif + endch = '}'; + if (ch == '(') { + endch = ')'; + command->grp_type = GRP_SUBSHELL; + } else { + /* bash does not allow "{echo...", requires whitespace */ + ch = i_getch(input); + if (ch != ' ' && ch != '\t' && ch != '\n') { + syntax_error_unexpected_ch(ch); + return 1; + } + nommu_addchr(&ctx->as_string, ch); + } + + { +#if !BB_MMU + char *as_string = NULL; +#endif + pipe_list = parse_stream(&as_string, input, endch); +#if !BB_MMU + if (as_string) + o_addstr(&ctx->as_string, as_string); +#endif + /* empty ()/{} or parse error? */ + if (!pipe_list || pipe_list == ERR_PTR) { + /* parse_stream already emitted error msg */ +#if !BB_MMU + free(as_string); +#endif + debug_printf_parse("parse_group return 1: " + "parse_stream returned %p\n", pipe_list); + return 1; + } + command->group = pipe_list; +#if !BB_MMU + as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */ + command->group_as_string = as_string; + debug_printf_parse("end of group, remembering as:'%s'\n", + command->group_as_string); +#endif + } + debug_printf_parse("parse_group return 0\n"); + return 0; + /* command remains "open", available for possible redirects */ } -/* basically useful version until someone wants to get fancier, - * see the bash man page under "Parameter Expansion" */ -static char *lookup_param(char *src) +#if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT +/* Subroutines for copying $(...) and `...` things */ +static void add_till_backquote(o_string *dest, struct in_str *input); +/* '...' */ +static void add_till_single_quote(o_string *dest, struct in_str *input) { - char *p=NULL; - if (src) { - p = getenv(src); - if (!p) - p = get_local_var(src); + while (1) { + int ch = i_getch(input); + if (ch == EOF) { + syntax_error_unterm_ch('\''); + /*xfunc_die(); - redundant */ + } + if (ch == '\'') + return; + o_addchr(dest, ch); + } +} +/* "...\"...`..`...." - do we need to handle "...$(..)..." too? */ +static void add_till_double_quote(o_string *dest, struct in_str *input) +{ + while (1) { + int ch = i_getch(input); + if (ch == EOF) { + syntax_error_unterm_ch('"'); + /*xfunc_die(); - redundant */ + } + if (ch == '"') + return; + if (ch == '\\') { /* \x. Copy both chars. */ + o_addchr(dest, ch); + ch = i_getch(input); + } + o_addchr(dest, ch); + if (ch == '`') { + add_till_backquote(dest, input); + o_addchr(dest, ch); + continue; + } + //if (ch == '$') ... + } +} +/* Process `cmd` - copy contents until "`" is seen. Complicated by + * \` quoting. + * "Within the backquoted style of command substitution, backslash + * shall retain its literal meaning, except when followed by: '$', '`', or '\'. + * The search for the matching backquote shall be satisfied by the first + * backquote found without a preceding backslash; during this search, + * if a non-escaped backquote is encountered within a shell comment, + * a here-document, an embedded command substitution of the $(command) + * form, or a quoted string, undefined results occur. A single-quoted + * or double-quoted string that begins, but does not end, within the + * "`...`" sequence produces undefined results." + * Example Output + * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST + */ +static void add_till_backquote(o_string *dest, struct in_str *input) +{ + while (1) { + int ch = i_getch(input); + if (ch == EOF) { + syntax_error_unterm_ch('`'); + /*xfunc_die(); - redundant */ + } + if (ch == '`') + return; + if (ch == '\\') { + /* \x. Copy both chars unless it is \` */ + int ch2 = i_getch(input); + if (ch2 == EOF) { + syntax_error_unterm_ch('`'); + /*xfunc_die(); - redundant */ + } + if (ch2 != '`' && ch2 != '$' && ch2 != '\\') + o_addchr(dest, ch); + ch = ch2; + } + o_addchr(dest, ch); + } +} +/* Process $(cmd) - copy contents until ")" is seen. Complicated by + * quoting and nested ()s. + * "With the $(command) style of command substitution, all characters + * following the open parenthesis to the matching closing parenthesis + * constitute the command. Any valid shell script can be used for command, + * except a script consisting solely of redirections which produces + * unspecified results." + * Example Output + * echo $(echo '(TEST)' BEST) (TEST) BEST + * echo $(echo 'TEST)' BEST) TEST) BEST + * echo $(echo \(\(TEST\) BEST) ((TEST) BEST + */ +static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl) +{ + int count = 0; + while (1) { + int ch = i_getch(input); + if (ch == EOF) { + syntax_error_unterm_ch(')'); + /*xfunc_die(); - redundant */ + } + if (ch == '(') + count++; + if (ch == ')') { + if (--count < 0) { + if (!dbl) + break; + if (i_peek(input) == ')') { + i_getch(input); + break; + } + } + } + o_addchr(dest, ch); + if (ch == '\'') { + add_till_single_quote(dest, input); + o_addchr(dest, ch); + continue; + } + if (ch == '"') { + add_till_double_quote(dest, input); + o_addchr(dest, ch); + continue; + } + if (ch == '\\') { + /* \x. Copy verbatim. Important for \(, \) */ + ch = i_getch(input); + if (ch == EOF) { + syntax_error_unterm_ch(')'); + /*xfunc_die(); - redundant */ + } + o_addchr(dest, ch); + continue; + } } - return p; } +#endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */ -/* return code: 0 for OK, 1 for syntax error */ -static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input) +/* Return code: 0 for OK, 1 for syntax error */ +#if BB_MMU +#define handle_dollar(as_string, dest, input) \ + handle_dollar(dest, input) +#endif +static int handle_dollar(o_string *as_string, + o_string *dest, + struct in_str *input) { - int i, advance=0; - char sep[]=" "; - int ch = input->peek(input); /* first character after the $ */ - debug_printf("handle_dollar: ch=%c\n",ch); + int expansion; + int ch = i_peek(input); /* first character after the $ */ + unsigned char quote_mask = dest->o_escape ? 0x80 : 0; + + debug_printf_parse("handle_dollar entered: ch='%c'\n", ch); if (isalpha(ch)) { - b_addchr(dest, SPECIAL_VAR_SYMBOL); - ctx->child->sp++; - while(ch=b_peek(input),isalnum(ch) || ch=='_') { - b_getch(input); - b_addchr(dest,ch); + ch = i_getch(input); + nommu_addchr(as_string, ch); + make_var: + o_addchr(dest, SPECIAL_VAR_SYMBOL); + while (1) { + debug_printf_parse(": '%c'\n", ch); + o_addchr(dest, ch | quote_mask); + quote_mask = 0; + ch = i_peek(input); + if (!isalnum(ch) && ch != '_') + break; + ch = i_getch(input); + nommu_addchr(as_string, ch); } - b_addchr(dest, SPECIAL_VAR_SYMBOL); + o_addchr(dest, SPECIAL_VAR_SYMBOL); } else if (isdigit(ch)) { - i = ch-'0'; /* XXX is $0 special? */ - if (i<global_argc) { - parse_string(dest, ctx, global_argv[i]); /* recursion */ - } - advance = 1; + make_one_char_var: + ch = i_getch(input); + nommu_addchr(as_string, ch); + o_addchr(dest, SPECIAL_VAR_SYMBOL); + debug_printf_parse(": '%c'\n", ch); + o_addchr(dest, ch | quote_mask); + o_addchr(dest, SPECIAL_VAR_SYMBOL); } else switch (ch) { - case '$': - b_adduint(dest,getpid()); - advance = 1; - break; - case '!': - if (last_bg_pid > 0) b_adduint(dest, last_bg_pid); - advance = 1; - break; - case '?': - b_adduint(dest,last_return_code); - advance = 1; - break; - case '#': - b_adduint(dest,global_argc ? global_argc-1 : 0); - advance = 1; - break; - case '{': - b_addchr(dest, SPECIAL_VAR_SYMBOL); - ctx->child->sp++; - b_getch(input); - /* XXX maybe someone will try to escape the '}' */ - while(ch=b_getch(input),ch!=EOF && ch!='}') { - b_addchr(dest,ch); - } - if (ch != '}') { - syntax(); - return 1; + case '$': /* pid */ + case '!': /* last bg pid */ + case '?': /* last exit code */ + case '#': /* number of args */ + case '*': /* args */ + case '@': /* args */ + goto make_one_char_var; + case '{': { + bool first_char, all_digits; + + o_addchr(dest, SPECIAL_VAR_SYMBOL); + ch = i_getch(input); + nommu_addchr(as_string, ch); + /* TODO: maybe someone will try to escape the '}' */ + expansion = 0; + first_char = true; + all_digits = false; + while (1) { + ch = i_getch(input); + nommu_addchr(as_string, ch); + if (ch == '}') { + break; } - b_addchr(dest, SPECIAL_VAR_SYMBOL); - break; - case '(': - b_getch(input); - process_command_subs(dest, ctx, input, ')'); - break; - case '*': - sep[0]=ifs[0]; - for (i=1; i<global_argc; i++) { - parse_string(dest, ctx, global_argv[i]); - if (i+1 < global_argc) parse_string(dest, ctx, sep); + + if (first_char) { + if (ch == '#') { + /* ${#var}: length of var contents */ + goto char_ok; + } + if (isdigit(ch)) { + all_digits = true; + goto char_ok; + } + /* They're being verbose and doing ${?} */ + if (i_peek(input) == '}' && strchr("$!?#*@_", ch)) + goto char_ok; } + + if (expansion < 2 + && ( (all_digits && !isdigit(ch)) + || (!all_digits && !isalnum(ch) && ch != '_') + ) + ) { + /* handle parameter expansions + * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02 + */ + if (first_char) + goto case_default; + switch (ch) { + case ':': /* null modifier */ + if (expansion == 0) { + debug_printf_parse(": null modifier\n"); + ++expansion; + break; + } + goto case_default; + case '#': /* remove prefix */ + case '%': /* remove suffix */ + if (expansion == 0) { + debug_printf_parse(": remove suffix/prefix\n"); + expansion = 2; + break; + } + goto case_default; + case '-': /* default value */ + case '=': /* assign default */ + case '+': /* alternative */ + case '?': /* error indicate */ + debug_printf_parse(": parameter expansion\n"); + expansion = 2; + break; + default: + case_default: + syntax_error_unterm_str("${name}"); + debug_printf_parse("handle_dollar return 1: unterminated ${name}\n"); + return 1; + } + } + char_ok: + debug_printf_parse(": '%c'\n", ch); + o_addchr(dest, ch | quote_mask); + quote_mask = 0; + first_char = false; + } /* while (1) */ + o_addchr(dest, SPECIAL_VAR_SYMBOL); + break; + } +#if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK) + case '(': { +# if !BB_MMU + int pos; +# endif + ch = i_getch(input); + nommu_addchr(as_string, ch); +# if ENABLE_SH_MATH_SUPPORT + if (i_peek(input) == '(') { + ch = i_getch(input); + nommu_addchr(as_string, ch); + o_addchr(dest, SPECIAL_VAR_SYMBOL); + o_addchr(dest, /*quote_mask |*/ '+'); +# if !BB_MMU + pos = dest->length; +# endif + add_till_closing_paren(dest, input, true); +# if !BB_MMU + if (as_string) { + o_addstr(as_string, dest->data + pos); + o_addchr(as_string, ')'); + o_addchr(as_string, ')'); + } +# endif + o_addchr(dest, SPECIAL_VAR_SYMBOL); break; - case '@': - case '-': - case '_': - /* still unhandled, but should be eventually */ - bb_error_msg("unhandled syntax: $%c",ch); - return 1; - break; - default: - b_addqchr(dest,'$',dest->quote); + } +# endif +# if ENABLE_HUSH_TICK + o_addchr(dest, SPECIAL_VAR_SYMBOL); + o_addchr(dest, quote_mask | '`'); +# if !BB_MMU + pos = dest->length; +# endif + add_till_closing_paren(dest, input, false); +# if !BB_MMU + if (as_string) { + o_addstr(as_string, dest->data + pos); + o_addchr(as_string, '`'); + } +# endif + o_addchr(dest, SPECIAL_VAR_SYMBOL); +# endif + break; } - /* Eat the character if the flag was set. If the compiler - * is smart enough, we could substitute "b_getch(input);" - * for all the "advance = 1;" above, and also end up with - * a nice size-optimized program. Hah! That'll be the day. - */ - if (advance) b_getch(input); +#endif + case '_': + ch = i_getch(input); + nommu_addchr(as_string, ch); + ch = i_peek(input); + if (isalnum(ch)) { /* it's $_name or $_123 */ + ch = '_'; + goto make_var; + } + /* else: it's $_ */ + /* TODO: */ + /* $_ Shell or shell script name; or last cmd name */ + /* $- Option flags set by set builtin or shell options (-i etc) */ + default: + o_addQchr(dest, '$'); + } + debug_printf_parse("handle_dollar return 0\n"); return 0; } -int parse_string(o_string *dest, struct p_context *ctx, const char *src) +#if BB_MMU +#define parse_stream_dquoted(as_string, dest, input, dquote_end) \ + parse_stream_dquoted(dest, input, dquote_end) +#endif +static int parse_stream_dquoted(o_string *as_string, + o_string *dest, + struct in_str *input, + int dquote_end) { - struct in_str foo; - setup_string_in_str(&foo, src); - return parse_stream(dest, ctx, &foo, '\0'); + int ch; + int next; + + again: + ch = i_getch(input); + if (ch != EOF) + nommu_addchr(as_string, ch); + if (ch == dquote_end) { /* may be only '"' or EOF */ + if (dest->o_assignment == NOT_ASSIGNMENT) + dest->o_escape ^= 1; + debug_printf_parse("parse_stream_dquoted return 0\n"); + return 0; + } + /* note: can't move it above ch == dquote_end check! */ + if (ch == EOF) { + syntax_error_unterm_ch('"'); + /*xfunc_die(); - redundant */ + } + next = '\0'; + if (ch != '\n') { + next = i_peek(input); + } + debug_printf_parse(": ch=%c (%d) escape=%d\n", + ch, ch, dest->o_escape); + if (ch == '\\') { + if (next == EOF) { + syntax_error("\\<eof>"); + xfunc_die(); + } + /* bash: + * "The backslash retains its special meaning [in "..."] + * only when followed by one of the following characters: + * $, `, ", \, or <newline>. A double quote may be quoted + * within double quotes by preceding it with a backslash." + */ + if (strchr("$`\"\\\n", next) != NULL) { + ch = i_getch(input); + if (ch != '\n') { + o_addqchr(dest, ch); + nommu_addchr(as_string, ch); + } + } else { + o_addqchr(dest, '\\'); + nommu_addchr(as_string, '\\'); + } + goto again; + } + if (ch == '$') { + if (handle_dollar(as_string, dest, input) != 0) { + debug_printf_parse("parse_stream_dquoted return 1: " + "handle_dollar returned non-0\n"); + return 1; + } + goto again; + } +#if ENABLE_HUSH_TICK + if (ch == '`') { + //int pos = dest->length; + o_addchr(dest, SPECIAL_VAR_SYMBOL); + o_addchr(dest, 0x80 | '`'); + add_till_backquote(dest, input); + o_addchr(dest, SPECIAL_VAR_SYMBOL); + //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos); + goto again; + } +#endif + o_addQchr(dest, ch); + if (ch == '=' + && (dest->o_assignment == MAYBE_ASSIGNMENT + || dest->o_assignment == WORD_IS_KEYWORD) + && is_well_formed_var_name(dest->data, '=') + ) { + dest->o_assignment = DEFINITELY_ASSIGNMENT; + } + goto again; } -/* return code is 0 for normal exit, 1 for syntax error */ -int parse_stream(o_string *dest, struct p_context *ctx, - struct in_str *input, int end_trigger) +/* + * Scan input until EOF or end_trigger char. + * Return a list of pipes to execute, or NULL on EOF + * or if end_trigger character is met. + * On syntax error, exit is shell is not interactive, + * reset parsing machinery and start parsing anew, + * or return ERR_PTR. + */ +static struct pipe *parse_stream(char **pstring, + struct in_str *input, + int end_trigger) { - unsigned int ch, m; - int redir_fd; - redir_type redir_style; - int next; + struct parse_context ctx; + o_string dest = NULL_O_STRING; + int is_in_dquote; + int heredoc_cnt; - /* Only double-quote state is handled in the state variable dest->quote. + /* Double-quote state is handled in the state variable is_in_dquote. * A single-quote triggers a bypass of the main loop until its mate is - * found. When recursing, quote state is passed in via dest->quote. */ - - debug_printf("parse_stream, end_trigger=%d\n",end_trigger); - while ((ch=b_getch(input))!=EOF) { - m = map[ch]; - next = (ch == '\n') ? 0 : b_peek(input); - debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d\n", - ch,ch,m,dest->quote); - if (m==0 || ((m==1 || m==2) && dest->quote)) { - b_addqchr(dest, ch, dest->quote); - } else { - if (m==2) { /* unquoted IFS */ - if (done_word(dest, ctx)) { - return 1; - } - /* If we aren't performing a substitution, treat a newline as a - * command separator. */ - if (end_trigger != '\0' && ch=='\n') - done_pipe(ctx,PIPE_SEQ); + * found. When recursing, quote state is passed in via dest->o_escape. + */ + debug_printf_parse("parse_stream entered, end_trigger='%c'\n", + end_trigger ? : 'X'); + debug_enter(); + + G.ifs = get_local_var_value("IFS"); + if (G.ifs == NULL) + G.ifs = " \t\n"; + + reset: +#if ENABLE_HUSH_INTERACTIVE + input->promptmode = 0; /* PS1 */ +#endif + /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */ + initialize_context(&ctx); + is_in_dquote = 0; + heredoc_cnt = 0; + while (1) { + const char *is_ifs; + const char *is_special; + int ch; + int next; + int redir_fd; + redir_type redir_style; + + if (is_in_dquote) { + /* dest.o_quoted = 1; - already is (see below) */ + if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) { + goto parse_error; + } + /* We reached closing '"' */ + is_in_dquote = 0; + } + ch = i_getch(input); + debug_printf_parse(": ch=%c (%d) escape=%d\n", + ch, ch, dest.o_escape); + if (ch == EOF) { + struct pipe *pi; + + if (heredoc_cnt) { + syntax_error_unterm_str("here document"); + goto parse_error; + } + /* end_trigger == '}' case errors out earlier, + * checking only ')' */ + if (end_trigger == ')') { + syntax_error_unterm_ch('('); /* exits */ + /* goto parse_error; */ + } + + if (done_word(&dest, &ctx)) { + goto parse_error; + } + o_free(&dest); + done_pipe(&ctx, PIPE_SEQ); + pi = ctx.list_head; + /* If we got nothing... */ + /* (this makes bare "&" cmd a no-op. + * bash says: "syntax error near unexpected token '&'") */ + if (pi->num_cmds == 0 + IF_HAS_KEYWORDS( && pi->res_word == RES_NONE) + ) { + free_pipe_list(pi); + pi = NULL; + } +#if !BB_MMU + debug_printf_parse("as_string '%s'\n", ctx.as_string.data); + if (pstring) + *pstring = ctx.as_string.data; + else + o_free_unsafe(&ctx.as_string); +#endif + debug_leave(); + debug_printf_parse("parse_stream return %p\n", pi); + return pi; + } + nommu_addchr(&ctx.as_string, ch); + is_ifs = strchr(G.ifs, ch); + is_special = strchr("<>;&|(){}#'" /* special outside of "str" */ + "\\$\"" USE_HUSH_TICK("`") /* always special */ + , ch); + + if (!is_special && !is_ifs) { /* ordinary char */ + ordinary_char: + o_addQchr(&dest, ch); + if ((dest.o_assignment == MAYBE_ASSIGNMENT + || dest.o_assignment == WORD_IS_KEYWORD) + && ch == '=' + && is_well_formed_var_name(dest.data, '=') + ) { + dest.o_assignment = DEFINITELY_ASSIGNMENT; } - if (ch == end_trigger && !dest->quote && ctx->w==RES_NONE) { - debug_printf("leaving parse_stream (triggered)\n"); - return 0; + continue; + } + + if (is_ifs) { + if (done_word(&dest, &ctx)) { + goto parse_error; + } + if (ch == '\n') { +#if ENABLE_HUSH_CASE + /* "case ... in <newline> word) ..." - + * newlines are ignored (but ';' wouldn't be) */ + if (ctx.command->argv == NULL + && ctx.ctx_res_w == RES_MATCH + ) { + continue; + } +#endif + /* Treat newline as a command separator. */ + done_pipe(&ctx, PIPE_SEQ); + debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt); + if (heredoc_cnt) { + if (fetch_heredocs(heredoc_cnt, &ctx, input)) { + goto parse_error; + } + heredoc_cnt = 0; + } + dest.o_assignment = MAYBE_ASSIGNMENT; + ch = ';'; + /* note: if (is_ifs) continue; + * will still trigger for us */ + } + } + + /* "cmd}" or "cmd }..." without semicolon or &: + * } is an ordinary char in this case, even inside { cmd; } + * Pathological example: { ""}; } should exec "}" cmd + */ + if (ch == '}') { + if (!IS_NULL_CMD(ctx.command) /* cmd } */ + || dest.length != 0 /* word} */ + || dest.o_quoted /* ""} */ + ) { + goto ordinary_char; + } + if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */ + goto skip_end_trigger; + /* else: } does terminate a group */ + } + + if (end_trigger && end_trigger == ch + && (ch != ';' || heredoc_cnt == 0) +#if ENABLE_HUSH_CASE + && (ch != ')' + || ctx.ctx_res_w != RES_MATCH + || (!dest.o_quoted && strcmp(dest.data, "esac") == 0) + ) +#endif + ) { + if (heredoc_cnt) { + /* This is technically valid: + * { cat <<HERE; }; echo Ok + * heredoc + * heredoc + * HERE + * but we don't support this. + * We require heredoc to be in enclosing {}/(), + * if any. + */ + syntax_error_unterm_str("here document"); + goto parse_error; + } + if (done_word(&dest, &ctx)) { + goto parse_error; + } + done_pipe(&ctx, PIPE_SEQ); + dest.o_assignment = MAYBE_ASSIGNMENT; + /* Do we sit outside of any if's, loops or case's? */ + if (!HAS_KEYWORDS + IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0)) + ) { + o_free(&dest); +#if !BB_MMU + debug_printf_parse("as_string '%s'\n", ctx.as_string.data); + if (pstring) + *pstring = ctx.as_string.data; + else + o_free_unsafe(&ctx.as_string); +#endif + debug_leave(); + debug_printf_parse("parse_stream return %p: " + "end_trigger char found\n", + ctx.list_head); + return ctx.list_head; + } + } + skip_end_trigger: + if (is_ifs) + continue; + + next = '\0'; + if (ch != '\n') { + next = i_peek(input); + } + + /* Catch <, > before deciding whether this word is + * an assignment. a=1 2>z b=2: b=2 is still assignment */ + switch (ch) { + case '>': + redir_fd = redirect_opt_num(&dest); + if (done_word(&dest, &ctx)) { + goto parse_error; + } + redir_style = REDIRECT_OVERWRITE; + if (next == '>') { + redir_style = REDIRECT_APPEND; + ch = i_getch(input); + nommu_addchr(&ctx.as_string, ch); } #if 0 - if (ch=='\n') { - /* Yahoo! Time to run with it! */ - done_pipe(ctx,PIPE_SEQ); - run_list(ctx->list_head); - initialize_context(ctx); + else if (next == '(') { + syntax_error(">(process) not supported"); + goto parse_error; } #endif - if (m!=2) switch (ch) { + if (parse_redirect(&ctx, redir_fd, redir_style, input)) + goto parse_error; + continue; /* back to top of while (1) */ + case '<': + redir_fd = redirect_opt_num(&dest); + if (done_word(&dest, &ctx)) { + goto parse_error; + } + redir_style = REDIRECT_INPUT; + if (next == '<') { + redir_style = REDIRECT_HEREDOC; + heredoc_cnt++; + debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt); + ch = i_getch(input); + nommu_addchr(&ctx.as_string, ch); + } else if (next == '>') { + redir_style = REDIRECT_IO; + ch = i_getch(input); + nommu_addchr(&ctx.as_string, ch); + } +#if 0 + else if (next == '(') { + syntax_error("<(process) not supported"); + goto parse_error; + } +#endif + if (parse_redirect(&ctx, redir_fd, redir_style, input)) + goto parse_error; + continue; /* back to top of while (1) */ + } + + if (dest.o_assignment == MAYBE_ASSIGNMENT + /* check that we are not in word in "a=1 2>word b=1": */ + && !ctx.pending_redirect + ) { + /* ch is a special char and thus this word + * cannot be an assignment */ + dest.o_assignment = NOT_ASSIGNMENT; + } + + switch (ch) { case '#': - if (dest->length == 0 && !dest->quote) { - while(ch=b_peek(input),ch!=EOF && ch!='\n') { b_getch(input); } + if (dest.length == 0) { + while (1) { + ch = i_peek(input); + if (ch == EOF || ch == '\n') + break; + i_getch(input); + /* note: we do not add it to &ctx.as_string */ + } + nommu_addchr(&ctx.as_string, '\n'); } else { - b_addqchr(dest, ch, dest->quote); + o_addQchr(&dest, ch); } break; case '\\': if (next == EOF) { - syntax(); - return 1; + syntax_error("\\<eof>"); + xfunc_die(); + } + ch = i_getch(input); + if (ch != '\n') { + o_addchr(&dest, '\\'); + nommu_addchr(&ctx.as_string, '\\'); + o_addchr(&dest, ch); + nommu_addchr(&ctx.as_string, ch); + /* Example: echo Hello \2>file + * we need to know that word 2 is quoted */ + dest.o_quoted = 1; } - b_addqchr(dest, '\\', dest->quote); - b_addqchr(dest, b_getch(input), dest->quote); break; case '$': - if (handle_dollar(dest, ctx, input)!=0) return 1; + if (handle_dollar(&ctx.as_string, &dest, input) != 0) { + debug_printf_parse("parse_stream parse error: " + "handle_dollar returned non-0\n"); + goto parse_error; + } break; case '\'': - dest->nonnull = 1; - while(ch=b_getch(input),ch!=EOF && ch!='\'') { - b_addchr(dest,ch); - } - if (ch==EOF) { - syntax(); - return 1; + dest.o_quoted = 1; + while (1) { + ch = i_getch(input); + if (ch == EOF) { + syntax_error_unterm_ch('\''); + /*xfunc_die(); - redundant */ + } + nommu_addchr(&ctx.as_string, ch); + if (ch == '\'') + break; + o_addqchr(&dest, ch); } break; case '"': - dest->nonnull = 1; - dest->quote = !dest->quote; + dest.o_quoted = 1; + is_in_dquote ^= 1; /* invert */ + if (dest.o_assignment == NOT_ASSIGNMENT) + dest.o_escape ^= 1; break; - case '`': - process_command_subs(dest, ctx, input, '`'); +#if ENABLE_HUSH_TICK + case '`': { +#if !BB_MMU + int pos; +#endif + o_addchr(&dest, SPECIAL_VAR_SYMBOL); + o_addchr(&dest, '`'); +#if !BB_MMU + pos = dest.length; +#endif + add_till_backquote(&dest, input); +#if !BB_MMU + o_addstr(&ctx.as_string, dest.data + pos); + o_addchr(&ctx.as_string, '`'); +#endif + o_addchr(&dest, SPECIAL_VAR_SYMBOL); + //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos); break; - case '>': - redir_fd = redirect_opt_num(dest); - done_word(dest, ctx); - redir_style=REDIRECT_OVERWRITE; - if (next == '>') { - redir_style=REDIRECT_APPEND; - b_getch(input); - } else if (next == '(') { - syntax(); /* until we support >(list) Process Substitution */ - return 1; + } +#endif + case ';': +#if ENABLE_HUSH_CASE + case_semi: +#endif + if (done_word(&dest, &ctx)) { + goto parse_error; } - setup_redirect(ctx, redir_fd, redir_style, input); - break; - case '<': - redir_fd = redirect_opt_num(dest); - done_word(dest, ctx); - redir_style=REDIRECT_INPUT; - if (next == '<') { - redir_style=REDIRECT_HEREIS; - b_getch(input); - } else if (next == '>') { - redir_style=REDIRECT_IO; - b_getch(input); - } else if (next == '(') { - syntax(); /* until we support <(list) Process Substitution */ - return 1; + done_pipe(&ctx, PIPE_SEQ); +#if ENABLE_HUSH_CASE + /* Eat multiple semicolons, detect + * whether it means something special */ + while (1) { + ch = i_peek(input); + if (ch != ';') + break; + ch = i_getch(input); + nommu_addchr(&ctx.as_string, ch); + if (ctx.ctx_res_w == RES_CASE_BODY) { + ctx.ctx_dsemicolon = 1; + ctx.ctx_res_w = RES_MATCH; + break; + } } - setup_redirect(ctx, redir_fd, redir_style, input); - break; - case ';': - done_word(dest, ctx); - done_pipe(ctx,PIPE_SEQ); +#endif + new_cmd: + /* We just finished a cmd. New one may start + * with an assignment */ + dest.o_assignment = MAYBE_ASSIGNMENT; break; case '&': - done_word(dest, ctx); - if (next=='&') { - b_getch(input); - done_pipe(ctx,PIPE_AND); + if (done_word(&dest, &ctx)) { + goto parse_error; + } + if (next == '&') { + ch = i_getch(input); + nommu_addchr(&ctx.as_string, ch); + done_pipe(&ctx, PIPE_AND); } else { - done_pipe(ctx,PIPE_BG); + done_pipe(&ctx, PIPE_BG); } - break; + goto new_cmd; case '|': - done_word(dest, ctx); - if (next=='|') { - b_getch(input); - done_pipe(ctx,PIPE_OR); + if (done_word(&dest, &ctx)) { + goto parse_error; + } +#if ENABLE_HUSH_CASE + if (ctx.ctx_res_w == RES_MATCH) + break; /* we are in case's "word | word)" */ +#endif + if (next == '|') { /* || */ + ch = i_getch(input); + nommu_addchr(&ctx.as_string, ch); + done_pipe(&ctx, PIPE_OR); } else { /* we could pick up a file descriptor choice here * with redirect_opt_num(), but bash doesn't do it. * "echo foo 2| cat" yields "foo 2". */ - done_command(ctx); + done_command(&ctx); } - break; + goto new_cmd; case '(': +#if ENABLE_HUSH_CASE + /* "case... in [(]word)..." - skip '(' */ + if (ctx.ctx_res_w == RES_MATCH + && ctx.command->argv == NULL /* not (word|(... */ + && dest.length == 0 /* not word(... */ + && dest.o_quoted == 0 /* not ""(... */ + ) { + continue; + } +#endif case '{': - if (parse_group(dest, ctx, input, ch)!=0) return 1; - break; + if (parse_group(&dest, &ctx, input, ch) != 0) { + goto parse_error; + } + goto new_cmd; case ')': +#if ENABLE_HUSH_CASE + if (ctx.ctx_res_w == RES_MATCH) + goto case_semi; +#endif case '}': - syntax(); /* Proper use of this character caught by end_trigger */ - return 1; - break; + /* proper use of this character is caught by end_trigger: + * if we see {, we call parse_group(..., end_trigger='}') + * and it will match } earlier (not here). */ + syntax_error_unexpected_ch(ch); + goto parse_error; default: - syntax(); /* this is really an internal logic error */ - return 1; + if (HUSH_DEBUG) + bb_error_msg_and_die("BUG: unexpected %c\n", ch); + } + } /* while (1) */ + + parse_error: + { + struct parse_context *pctx; + IF_HAS_KEYWORDS(struct parse_context *p2;) + + /* Clean up allocated tree. + * Samples for finding leaks on syntax error recovery path. + * Run them from interactive shell, watch pmap `pidof hush`. + * while if false; then false; fi do break; done + * (bash accepts it) + * while if false; then false; fi; do break; fi + * Samples to catch leaks at execution: + * while if (true | {true;}); then echo ok; fi; do break; done + * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done + */ + pctx = &ctx; + do { + /* Update pipe/command counts, + * otherwise freeing may miss some */ + done_pipe(pctx, PIPE_SEQ); + debug_printf_clean("freeing list %p from ctx %p\n", + pctx->list_head, pctx); + debug_print_tree(pctx->list_head, 0); + free_pipe_list(pctx->list_head); + debug_printf_clean("freed list %p\n", pctx->list_head); +#if !BB_MMU + o_free_unsafe(&pctx->as_string); +#endif + IF_HAS_KEYWORDS(p2 = pctx->stack;) + if (pctx != &ctx) { + free(pctx); } + IF_HAS_KEYWORDS(pctx = p2;) + } while (HAS_KEYWORDS && pctx); + /* Free text, clear all dest fields */ + o_free(&dest); + /* If we are not in top-level parse, we return, + * our caller will propagate error. + */ + if (end_trigger != ';') { +#if !BB_MMU + if (pstring) + *pstring = NULL; +#endif + debug_leave(); + return ERR_PTR; } + /* Discard cached input, force prompt */ + input->p = NULL; + USE_HUSH_INTERACTIVE(input->promptme = 1;) + goto reset; } - /* complain if quote? No, maybe we just finished a command substitution - * that was quoted. Example: - * $ echo "`cat foo` plus more" - * and we just got the EOF generated by the subshell that ran "cat foo" - * The only real complaint is if we got an EOF when end_trigger != '\0', - * that is, we were really supposed to get end_trigger, and never got - * one before the EOF. Can't use the standard "syntax error" return code, - * so that parse_stream_outer can distinguish the EOF and exit smoothly. */ - debug_printf("leaving parse_stream (EOF)\n"); - if (end_trigger != '\0') return -1; - return 0; -} - -void mapset(const unsigned char *set, int code) -{ - const unsigned char *s; - for (s=set; *s; s++) map[*s] = code; -} - -void update_ifs_map(void) -{ - /* char *ifs and char map[256] are both globals. */ - ifs = getenv("IFS"); - if (ifs == NULL) ifs=" \t\n"; - /* Precompute a list of 'flow through' behavior so it can be treated - * quickly up front. Computation is necessary because of IFS. - * Special case handling of IFS == " \t\n" is not implemented. - * The map[] array only really needs two bits each, and on most machines - * that would be faster because of the reduced L1 cache footprint. - */ - memset(map,0,sizeof(map)); /* most characters flow through always */ - mapset("\\$'\"`", 3); /* never flow through */ - mapset("<>;&|(){}#", 1); /* flow through if quoted */ - mapset(ifs, 2); /* also flow through if quoted */ } -/* most recursion does not come through here, the exeception is - * from builtin_source() */ -int parse_stream_outer(struct in_str *inp, int flag) +/* Executing from string: eval, sh -c '...' + * or from file: /etc/profile, . file, sh <script>, sh (intereactive) + * end_trigger controls how often we stop parsing + * NUL: parse all, execute, return + * ';': parse till ';' or newline, execute, repeat till EOF + */ +static void parse_and_run_stream(struct in_str *inp, int end_trigger) { + while (1) { + struct pipe *pipe_list; - struct p_context ctx; - o_string temp=NULL_O_STRING; - int rcode; - do { - ctx.type = flag; - initialize_context(&ctx); - update_ifs_map(); - if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) mapset(";$&|", 0); - inp->promptmode=1; - rcode = parse_stream(&temp, &ctx, inp, '\n'); - if (rcode != 1 && ctx.old_flag != 0) { - syntax(); - } - if (rcode != 1 && ctx.old_flag == 0) { - done_word(&temp, &ctx); - done_pipe(&ctx,PIPE_SEQ); - run_list(ctx.list_head); - } else { - if (ctx.old_flag != 0) { - free(ctx.stack); - b_reset(&temp); - } - temp.nonnull = 0; - temp.quote = 0; - inp->p = NULL; - free_pipe_list(ctx.list_head,0); - } - b_free(&temp); - } while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP)); /* loop on syntax errors, return on EOF */ - return 0; + pipe_list = parse_stream(NULL, inp, end_trigger); + if (!pipe_list) /* EOF */ + break; + debug_print_tree(pipe_list, 0); + debug_printf_exec("parse_and_run_stream: run_and_free_list\n"); + run_and_free_list(pipe_list); + } } -static int parse_string_outer(const char *s, int flag) +static void parse_and_run_string(const char *s) { struct in_str input; setup_string_in_str(&input, s); - return parse_stream_outer(&input, flag); + parse_and_run_stream(&input, '\0'); } -static int parse_file_outer(FILE *f) +static void parse_and_run_file(FILE *f) { - int rcode; struct in_str input; setup_file_in_str(&input, f); - rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON); - return rcode; + parse_and_run_stream(&input, ';'); } -/* Make sure we have a controlling tty. If we get started under a job - * aware app (like bash for example), make sure we are now in charge so - * we don't fight over who gets the foreground */ -static void setup_job_control(void) +/* Called a few times only (or even once if "sh -c") */ +static void block_signals(int second_time) { - static pid_t shell_pgrp; - /* Loop until we are in the foreground. */ - while (tcgetpgrp (shell_terminal) != (shell_pgrp = getpgrp ())) - kill (- shell_pgrp, SIGTTIN); - - /* Ignore interactive and job-control signals. */ - signal(SIGINT, SIG_IGN); - signal(SIGQUIT, SIG_IGN); - signal(SIGTERM, SIG_IGN); - signal(SIGTSTP, SIG_IGN); - signal(SIGTTIN, SIG_IGN); - signal(SIGTTOU, SIG_IGN); - signal(SIGCHLD, SIG_IGN); + unsigned sig; + unsigned mask; + + mask = (1 << SIGQUIT); + if (G_interactive_fd) { + mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS; + if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */ + mask |= SPECIAL_JOB_SIGS; + } + G.non_DFL_mask = mask; + + if (!second_time) + sigprocmask(SIG_SETMASK, NULL, &G.blocked_set); + sig = 0; + while (mask) { + if (mask & 1) + sigaddset(&G.blocked_set, sig); + mask >>= 1; + sig++; + } + sigdelset(&G.blocked_set, SIGCHLD); + + sigprocmask(SIG_SETMASK, &G.blocked_set, + second_time ? NULL : &G.inherited_set); + /* POSIX allows shell to re-enable SIGCHLD + * even if it was SIG_IGN on entry */ +#if ENABLE_HUSH_FAST + G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */ + if (!second_time) + signal(SIGCHLD, SIGCHLD_handler); +#else + if (!second_time) + signal(SIGCHLD, SIG_DFL); +#endif +} - /* Put ourselves in our own process group. */ - setsid(); - shell_pgrp = getpid (); - setpgid (shell_pgrp, shell_pgrp); +#if ENABLE_HUSH_JOB +/* helper */ +static void maybe_set_to_sigexit(int sig) +{ + void (*handler)(int); + /* non_DFL_mask'ed signals are, well, masked, + * no need to set handler for them. + */ + if (!((G.non_DFL_mask >> sig) & 1)) { + handler = signal(sig, sigexit); + if (handler == SIG_IGN) /* oops... restore back to IGN! */ + signal(sig, handler); + } +} +/* Set handlers to restore tty pgrp and exit */ +static void set_fatal_handlers(void) +{ + /* We _must_ restore tty pgrp on fatal signals */ + if (HUSH_DEBUG) { + maybe_set_to_sigexit(SIGILL ); + maybe_set_to_sigexit(SIGFPE ); + maybe_set_to_sigexit(SIGBUS ); + maybe_set_to_sigexit(SIGSEGV); + maybe_set_to_sigexit(SIGTRAP); + } /* else: hush is perfect. what SEGV? */ + maybe_set_to_sigexit(SIGABRT); + /* bash 3.2 seems to handle these just like 'fatal' ones */ + maybe_set_to_sigexit(SIGPIPE); + maybe_set_to_sigexit(SIGALRM); + /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked. + * if we aren't interactive... but in this case + * we never want to restore pgrp on exit, and this fn is not called */ + /*maybe_set_to_sigexit(SIGHUP );*/ + /*maybe_set_to_sigexit(SIGTERM);*/ + /*maybe_set_to_sigexit(SIGINT );*/ +} +#endif - /* Grab control of the terminal. */ - tcsetpgrp(shell_terminal, shell_pgrp); +static int set_mode(const char cstate, const char mode) +{ + int state = (cstate == '-' ? 1 : 0); + switch (mode) { + case 'n': G.fake_mode = state; break; + case 'x': /*G.debug_mode = state;*/ break; + default: return EXIT_FAILURE; + } + return EXIT_SUCCESS; } +int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int hush_main(int argc, char **argv) { + static const struct variable const_shell_ver = { + .next = NULL, + .varstr = (char*)hush_version_str, + .max_len = 1, /* 0 can provoke free(name) */ + .flg_export = 1, + .flg_read_only = 1, + }; + int signal_mask_is_inited = 0; int opt; - FILE *input; - char **e = environ; - - /* XXX what should these be while sourcing /etc/profile? */ - global_argc = argc; - global_argv = argv; - - /* (re?) initialize globals. Sometimes hush_main() ends up calling - * hush_main(), therefore we cannot rely on the BSS to zero out this - * stuff. Reset these to 0 every time. */ - ifs = NULL; - /* map[] is taken care of with call to update_ifs_map() */ - fake_mode = 0; - interactive = 0; - close_me_head = NULL; - last_bg_pid = 0; - job_list = NULL; - last_jobid = 0; - - /* Initialize some more globals to non-zero values */ - set_cwd(); -#ifdef CONFIG_FEATURE_COMMAND_EDITING - cmdedit_set_initial_prompt(); -#else - PS1 = NULL; + char **e; + struct variable *cur_var; + + INIT_G(); + if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */ + G.last_exitcode = EXIT_SUCCESS; +#if !BB_MMU + G.argv0_for_re_execing = argv[0]; #endif - PS2 = "> "; - - /* initialize our shell local variables with the values + /* Deal with HUSH_VERSION */ + G.shell_ver = const_shell_ver; /* copying struct here */ + G.top_var = &G.shell_ver; + debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION"); + unsetenv("HUSH_VERSION"); /* in case it exists in initial env */ + /* Initialize our shell local variables with the values * currently living in the environment */ - if (e) { - for (; *e; e++) - set_local_var(*e, 2); /* without call putenv() */ + cur_var = G.top_var; + e = environ; + if (e) while (*e) { + char *value = strchr(*e, '='); + if (value) { /* paranoia */ + cur_var->next = xzalloc(sizeof(*cur_var)); + cur_var = cur_var->next; + cur_var->varstr = *e; + cur_var->max_len = strlen(*e); + cur_var->flg_export = 1; + } + e++; } + debug_printf_env("putenv '%s'\n", hush_version_str); + putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */ +#if ENABLE_FEATURE_EDITING + G.line_input_state = new_line_input_t(FOR_SHELL); +#endif + G.global_argc = argc; + G.global_argv = argv; + /* Initialize some more globals to non-zero values */ + set_cwd(); + cmdedit_update_prompt(); - last_return_code=EXIT_SUCCESS; + if (setjmp(die_jmp)) { + /* xfunc has failed! die die die */ + /* no EXIT traps, this is an escape hatch! */ + G.exiting = 1; + hush_exit(xfunc_error_retval); + } + /* Shell is non-interactive at first. We need to call + * block_signals(0) if we are going to execute "sh <script>", + * "sh -c <cmds>" or login shell's /etc/profile and friends. + * If we later decide that we are interactive, we run block_signals(0) + * (or re-run block_signals(1) if we ran block_signals(0) before) + * in order to intercept (more) signals. + */ - if (argv[0] && argv[0][0] == '-') { - debug_printf("\nsourcing /etc/profile\n"); - if ((input = fopen("/etc/profile", "r")) != NULL) { - mark_open(fileno(input)); - parse_file_outer(input); - mark_closed(fileno(input)); - fclose(input); - } - } - input=stdin; - - while ((opt = getopt(argc, argv, "c:xif")) > 0) { + /* Parse options */ + /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */ + while (1) { + opt = getopt(argc, argv, "c:xins" +#if !BB_MMU + "<:$:R:V:" +# if ENABLE_HUSH_FUNCTIONS + "F:" +# endif +#endif + ); + if (opt <= 0) + break; switch (opt) { - case 'c': - { - global_argv = argv+optind; - global_argc = argc-optind; - opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON); - goto final_return; - } - break; - case 'i': - interactive++; - break; - case 'f': - fake_mode++; + case 'c': + if (!G.root_pid) + G.root_pid = getpid(); + G.global_argv = argv + optind; + if (!argv[optind]) { + /* -c 'script' (no params): prevent empty $0 */ + *--G.global_argv = argv[0]; + optind--; + } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */ + G.global_argc = argc - optind; + block_signals(0); /* 0: called 1st time */ + parse_and_run_string(optarg); + goto final_return; + case 'i': + /* Well, we cannot just declare interactiveness, + * we have to have some stuff (ctty, etc) */ + /* G_interactive_fd++; */ + break; + case 's': + /* "-s" means "read from stdin", but this is how we always + * operate, so simply do nothing here. */ + break; +#if !BB_MMU + case '<': /* "big heredoc" support */ + full_write(STDOUT_FILENO, optarg, strlen(optarg)); + _exit(0); + case '$': + G.root_pid = bb_strtou(optarg, &optarg, 16); + optarg++; + G.last_bg_pid = bb_strtou(optarg, &optarg, 16); + optarg++; + G.last_exitcode = bb_strtou(optarg, &optarg, 16); +# if ENABLE_HUSH_LOOPS + optarg++; + G.depth_of_loop = bb_strtou(optarg, &optarg, 16); +# endif + break; + case 'R': + case 'V': + set_local_var(xstrdup(optarg), 0, opt == 'R'); + break; +# if ENABLE_HUSH_FUNCTIONS + case 'F': { + struct function *funcp = new_function(optarg); + /* funcp->name is already set to optarg */ + /* funcp->body is set to NULL. It's a special case. */ + funcp->body_as_string = argv[optind]; + optind++; + break; + } +# endif +#endif + case 'n': + case 'x': + if (!set_mode('-', opt)) break; - default: + default: #ifndef BB_VER - fprintf(stderr, "Usage: sh [FILE]...\n" - " or: sh -c command [args]...\n\n"); - exit(EXIT_FAILURE); + fprintf(stderr, "Usage: sh [FILE]...\n" + " or: sh -c command [args]...\n\n"); + exit(EXIT_FAILURE); #else - bb_show_usage(); + bb_show_usage(); #endif } + } /* option parsing loop */ + + if (!G.root_pid) + G.root_pid = getpid(); + + /* If we are login shell... */ + if (argv[0] && argv[0][0] == '-') { + FILE *input; + debug_printf("sourcing /etc/profile\n"); + input = fopen_for_read("/etc/profile"); + if (input != NULL) { + close_on_exec_on(fileno(input)); + block_signals(0); /* 0: called 1st time */ + signal_mask_is_inited = 1; + parse_and_run_file(input); + fclose(input); + } + /* bash: after sourcing /etc/profile, + * tries to source (in the given order): + * ~/.bash_profile, ~/.bash_login, ~/.profile, + * stopping of first found. --noprofile turns this off. + * bash also sources ~/.bash_logout on exit. + * If called as sh, skips .bash_XXX files. + */ } - /* A shell is interactive if the `-i' flag was given, or if all of + + if (argv[optind]) { + FILE *input; + /* + * "bash <script>" (which is never interactive (unless -i?)) + * sources $BASH_ENV here (without scanning $PATH). + * If called as sh, does the same but with $ENV. + */ + debug_printf("running script '%s'\n", argv[optind]); + G.global_argv = argv + optind; + G.global_argc = argc - optind; + input = xfopen_for_read(argv[optind]); + close_on_exec_on(fileno(input)); + if (!signal_mask_is_inited) + block_signals(0); /* 0: called 1st time */ + parse_and_run_file(input); +#if ENABLE_FEATURE_CLEAN_UP + fclose(input); +#endif + goto final_return; + } + + /* Up to here, shell was non-interactive. Now it may become one. + * NB: don't forget to (re)run block_signals(0/1) as needed. + */ + + /* A shell is interactive if the '-i' flag was given, or if all of * the following conditions are met: - * no -c command + * no -c command * no arguments remaining or the -s flag given * standard input is a terminal * standard output is a terminal - * Refer to Posix.2, the description of the `sh' utility. */ - if (argv[optind]==NULL && input==stdin && - isatty(fileno(stdin)) && isatty(fileno(stdout))) { - interactive++; + * Refer to Posix.2, the description of the 'sh' utility. + */ +#if ENABLE_HUSH_JOB + if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) { + G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO); + debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp); + if (G_saved_tty_pgrp < 0) + G_saved_tty_pgrp = 0; + + /* try to dup stdin to high fd#, >= 255 */ + G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255); + if (G_interactive_fd < 0) { + /* try to dup to any fd */ + G_interactive_fd = dup(STDIN_FILENO); + if (G_interactive_fd < 0) { + /* give up */ + G_interactive_fd = 0; + G_saved_tty_pgrp = 0; + } + } +// TODO: track & disallow any attempts of user +// to (inadvertently) close/redirect G_interactive_fd } + debug_printf("interactive_fd:%d\n", G_interactive_fd); + if (G_interactive_fd) { + close_on_exec_on(G_interactive_fd); + + if (G_saved_tty_pgrp) { + /* If we were run as 'hush &', sleep until we are + * in the foreground (tty pgrp == our pgrp). + * If we get started under a job aware app (like bash), + * make sure we are now in charge so we don't fight over + * who gets the foreground */ + while (1) { + pid_t shell_pgrp = getpgrp(); + G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd); + if (G_saved_tty_pgrp == shell_pgrp) + break; + /* send TTIN to ourself (should stop us) */ + kill(- shell_pgrp, SIGTTIN); + } + } - debug_printf("\ninteractive=%d\n", interactive); - if (interactive) { - /* Looks like they want an interactive shell */ -#ifndef CONFIG_FEATURE_SH_EXTRA_QUIET - printf( "\n\n" BB_BANNER " hush - the humble shell v0.01 (testing)\n"); - printf( "Enter 'help' for a list of built-in commands.\n\n"); + /* Block some signals */ + block_signals(signal_mask_is_inited); + + if (G_saved_tty_pgrp) { + /* Set other signals to restore saved_tty_pgrp */ + set_fatal_handlers(); + /* Put ourselves in our own process group + * (bash, too, does this only if ctty is available) */ + bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */ + /* Grab control of the terminal */ + tcsetpgrp(G_interactive_fd, getpid()); + } + /* -1 is special - makes xfuncs longjmp, not exit + * (we reset die_sleep = 0 whereever we [v]fork) */ + enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */ + } else if (!signal_mask_is_inited) { + block_signals(0); /* 0: called 1st time */ + } /* else: block_signals(0) was done before */ +#elif ENABLE_HUSH_INTERACTIVE + /* No job control compiled in, only prompt/line editing */ + if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) { + G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255); + if (G_interactive_fd < 0) { + /* try to dup to any fd */ + G_interactive_fd = dup(STDIN_FILENO); + if (G_interactive_fd < 0) + /* give up */ + G_interactive_fd = 0; + } + } + if (G_interactive_fd) { + close_on_exec_on(G_interactive_fd); + block_signals(signal_mask_is_inited); + } else if (!signal_mask_is_inited) { + block_signals(0); + } +#else + /* We have interactiveness code disabled */ + if (!signal_mask_is_inited) { + block_signals(0); + } #endif - setup_job_control(); + /* bash: + * if interactive but not a login shell, sources ~/.bashrc + * (--norc turns this off, --rcfile <file> overrides) + */ + + if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) { + printf("\n\n%s hush - the humble shell\n", bb_banner); + if (ENABLE_HUSH_HELP) + puts("Enter 'help' for a list of built-in commands."); + puts(""); } - - if (argv[optind]==NULL) { - opt=parse_file_outer(stdin); - goto final_return; + + parse_and_run_file(stdin); + + final_return: +#if ENABLE_FEATURE_CLEAN_UP + if (G.cwd != bb_msg_unknown) + free((char*)G.cwd); + cur_var = G.top_var->next; + while (cur_var) { + struct variable *tmp = cur_var; + if (!cur_var->max_len) + free(cur_var->varstr); + cur_var = cur_var->next; + free(tmp); } +#endif + hush_exit(G.last_exitcode); +} - debug_printf("\nrunning script '%s'\n", argv[optind]); - global_argv = argv+optind; - global_argc = argc-optind; - input = bb_xfopen(argv[optind], "r"); - opt = parse_file_outer(input); -#ifdef CONFIG_FEATURE_CLEAN_UP - fclose(input); - if (cwd && cwd != bb_msg_unknown) - free((char*)cwd); +#if ENABLE_LASH +int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +int lash_main(int argc, char **argv) +{ + //bb_error_msg("lash is deprecated, please use hush instead"); + return hush_main(argc, argv); +} +#endif + + +/* + * Built-ins + */ +static int builtin_true(char **argv UNUSED_PARAM) +{ + return 0; +} + +static int builtin_test(char **argv) +{ + int argc = 0; + while (*argv) { + argc++; + argv++; + } + return test_main(argc, argv - argc); +} + +static int builtin_echo(char **argv) +{ + int argc = 0; + while (*argv) { + argc++; + argv++; + } + return echo_main(argc, argv - argc); +} + +static int builtin_eval(char **argv) +{ + int rcode = EXIT_SUCCESS; + + if (*++argv) { + char *str = expand_strvec_to_string(argv); + /* bash: + * eval "echo Hi; done" ("done" is syntax error): + * "echo Hi" will not execute too. + */ + parse_and_run_string(str); + free(str); + rcode = G.last_exitcode; + } + return rcode; +} + +static int builtin_cd(char **argv) +{ + const char *newdir = argv[1]; + if (newdir == NULL) { + /* bash does nothing (exitcode 0) if HOME is ""; if it's unset, + * bash says "bash: cd: HOME not set" and does nothing + * (exitcode 1) + */ + newdir = get_local_var_value("HOME") ? : "/"; + } + if (chdir(newdir)) { + /* Mimic bash message exactly */ + bb_perror_msg("cd: %s", newdir); + return EXIT_FAILURE; + } + set_cwd(); + return EXIT_SUCCESS; +} + +static int builtin_exec(char **argv) +{ + if (*++argv == NULL) + return EXIT_SUCCESS; /* bash does this */ { - struct variables *cur, *tmp; - for(cur = top_vars; cur; cur = tmp) { - tmp = cur->next; - if (!cur->flg_read_only) { - free(cur->name); - free(cur->value); - free(cur); +#if !BB_MMU + nommu_save_t dummy; +#endif + /* TODO: if exec fails, bash does NOT exit! We do... */ + pseudo_exec_argv(&dummy, argv, 0, NULL); + /* never returns */ + } +} + +static int builtin_exit(char **argv) +{ + debug_printf_exec("%s()\n", __func__); + + /* interactive bash: + * # trap "echo EEE" EXIT + * # exit + * exit + * There are stopped jobs. + * (if there are _stopped_ jobs, running ones don't count) + * # exit + * exit + # EEE (then bash exits) + * + * we can use G.exiting = -1 as indicator "last cmd was exit" + */ + + /* note: EXIT trap is run by hush_exit */ + if (*++argv == NULL) + hush_exit(G.last_exitcode); + /* mimic bash: exit 123abc == exit 255 + error msg */ + xfunc_error_retval = 255; + /* bash: exit -2 == exit 254, no error msg */ + hush_exit(xatoi(*argv) & 0xff); +} + +static void print_escaped(const char *s) +{ + do { + if (*s != '\'') { + const char *p; + + p = strchrnul(s, '\''); + /* print 'xxxx', possibly just '' */ + printf("'%.*s'", (int)(p - s), s); + if (*p == '\0') + break; + s = p; + } + /* s points to '; print "'''...'''" */ + putchar('"'); + do putchar('\''); while (*++s == '\''); + putchar('"'); + } while (*s); +} + +static int builtin_export(char **argv) +{ + unsigned opt_unexport; + + if (argv[1] == NULL) { + char **e = environ; + if (e) { + while (*e) { +#if 0 + puts(*e++); +#else + /* ash emits: export VAR='VAL' + * bash: declare -x VAR="VAL" + * we follow ash example */ + const char *s = *e++; + const char *p = strchr(s, '='); + + if (!p) /* wtf? take next variable */ + continue; + /* export var= */ + printf("export %.*s", (int)(p - s) + 1, s); + print_escaped(p + 1); + putchar('\n'); +#endif } + /*fflush(stdout); - done after each builtin anyway */ } + return EXIT_SUCCESS; } + +#if ENABLE_HUSH_EXPORT_N + /* "!": do not abort on errors */ + /* "+": stop at 1st non-option */ + opt_unexport = getopt32(argv, "!+n"); + if (opt_unexport == (unsigned)-1) + return EXIT_FAILURE; + argv += optind; +#else + opt_unexport = 0; + argv++; #endif -final_return: - return(opt?opt:last_return_code); + do { + char *name = *argv; + + /* So far we do not check that name is valid (TODO?) */ + + if (strchr(name, '=') == NULL) { + struct variable *var; + + var = get_local_var(name); + if (opt_unexport) { + /* export -n NAME (without =VALUE) */ + if (var) { + var->flg_export = 0; + debug_printf_env("%s: unsetenv '%s'\n", __func__, name); + unsetenv(name); + } /* else: export -n NOT_EXISTING_VAR: no-op */ + continue; + } + /* export NAME (without =VALUE) */ + if (var) { + var->flg_export = 1; + debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr); + putenv(var->varstr); + continue; + } + /* Exporting non-existing variable. + * bash does not put it in environment, + * but remembers that it is exported, + * and does put it in env when it is set later. + * We just set it to "" and export. */ + name = xasprintf("%s=", name); + } else { + /* (Un)exporting NAME=VALUE */ + name = xstrdup(name); + } + set_local_var(name, + /*export:*/ (opt_unexport ? -1 : 1), + /*readonly:*/ 0 + ); + } while (*++argv); + + return EXIT_SUCCESS; } -static char *insert_var_value(char *inp) +static int builtin_trap(char **argv) { - int res_str_len = 0; - int len; - int done = 0; - char *p, *p1, *res_str = NULL; - - while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) { - if (p != inp) { - len = p - inp; - res_str = xrealloc(res_str, (res_str_len + len)); - strncpy((res_str + res_str_len), inp, len); - res_str_len += len; - } - inp = ++p; - p = strchr(inp, SPECIAL_VAR_SYMBOL); - *p = '\0'; - if ((p1 = lookup_param(inp))) { - len = res_str_len + strlen(p1); - res_str = xrealloc(res_str, (1 + len)); - strcpy((res_str + res_str_len), p1); - res_str_len = len; - } - *p = SPECIAL_VAR_SYMBOL; - inp = ++p; - done = 1; - } - if (done) { - res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp))); - strcpy((res_str + res_str_len), inp); - while ((p = strchr(res_str, '\n'))) { - *p = ' '; - } - } - return (res_str == NULL) ? inp : res_str; -} - -static char **make_list_in(char **inp, char *name) -{ - int len, i; - int name_len = strlen(name); - int n = 0; - char **list; - char *p1, *p2, *p3; - - /* create list of variable values */ - list = xmalloc(sizeof(*list)); - for (i = 0; inp[i]; i++) { - p3 = insert_var_value(inp[i]); - p1 = p3; - while (*p1) { - if ((*p1 == ' ')) { - p1++; + int sig; + char *new_cmd; + + if (!G.traps) + G.traps = xzalloc(sizeof(G.traps[0]) * NSIG); + + argv++; + if (!*argv) { + int i; + /* No args: print all trapped */ + for (i = 0; i < NSIG; ++i) { + if (G.traps[i]) { + printf("trap -- "); + print_escaped(G.traps[i]); + printf(" %s\n", get_signame(i)); + } + } + /*fflush(stdout); - done after each builtin anyway */ + return EXIT_SUCCESS; + } + + new_cmd = NULL; + /* If first arg is a number: reset all specified signals */ + sig = bb_strtou(*argv, NULL, 10); + if (errno == 0) { + int ret; + process_sig_list: + ret = EXIT_SUCCESS; + while (*argv) { + sig = get_signum(*argv++); + if (sig < 0 || sig >= NSIG) { + ret = EXIT_FAILURE; + /* Mimic bash message exactly */ + bb_perror_msg("trap: %s: invalid signal specification", argv[-1]); continue; } - if ((p2 = strchr(p1, ' '))) { - len = p2 - p1; - } else { - len = strlen(p1); - p2 = p1 + len; - } - /* we use n + 2 in realloc for list,because we add - * new element and then we will add NULL element */ - list = xrealloc(list, sizeof(*list) * (n + 2)); - list[n] = xmalloc(2 + name_len + len); - strcpy(list[n], name); - strcat(list[n], "="); - strncat(list[n], p1, len); - list[n++][name_len + len + 1] = '\0'; - p1 = p2; - } - if (p3 != inp[i]) free(p3); - } - list[n] = NULL; - return list; -} -/* Make new string for parser */ -static char * make_string(char ** inp) + free(G.traps[sig]); + G.traps[sig] = xstrdup(new_cmd); + + debug_printf("trap: setting SIG%s (%i) to '%s'", + get_signame(sig), sig, G.traps[sig]); + + /* There is no signal for 0 (EXIT) */ + if (sig == 0) + continue; + + if (new_cmd) { + sigaddset(&G.blocked_set, sig); + } else { + /* There was a trap handler, we are removing it + * (if sig has non-DFL handling, + * we don't need to do anything) */ + if (sig < 32 && (G.non_DFL_mask & (1 << sig))) + continue; + sigdelset(&G.blocked_set, sig); + } + } + sigprocmask(SIG_SETMASK, &G.blocked_set, NULL); + return ret; + } + + if (!argv[1]) { /* no second arg */ + bb_error_msg("trap: invalid arguments"); + return EXIT_FAILURE; + } + + /* First arg is "-": reset all specified to default */ + /* First arg is "--": skip it, the rest is "handler SIGs..." */ + /* Everything else: set arg as signal handler + * (includes "" case, which ignores signal) */ + if (argv[0][0] == '-') { + if (argv[0][1] == '\0') { /* "-" */ + /* new_cmd remains NULL: "reset these sigs" */ + goto reset_traps; + } + if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */ + argv++; + } + /* else: "-something", no special meaning */ + } + new_cmd = *argv; + reset_traps: + argv++; + goto process_sig_list; +} + +#if ENABLE_HUSH_JOB +/* built-in 'fg' and 'bg' handler */ +static int builtin_fg_bg(char **argv) +{ + int i, jobnum; + struct pipe *pi; + + if (!G_interactive_fd) + return EXIT_FAILURE; + + /* If they gave us no args, assume they want the last backgrounded task */ + if (!argv[1]) { + for (pi = G.job_list; pi; pi = pi->next) { + if (pi->jobid == G.last_jobid) { + goto found; + } + } + bb_error_msg("%s: no current job", argv[0]); + return EXIT_FAILURE; + } + if (sscanf(argv[1], "%%%d", &jobnum) != 1) { + bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]); + return EXIT_FAILURE; + } + for (pi = G.job_list; pi; pi = pi->next) { + if (pi->jobid == jobnum) { + goto found; + } + } + bb_error_msg("%s: %d: no such job", argv[0], jobnum); + return EXIT_FAILURE; + found: + /* TODO: bash prints a string representation + * of job being foregrounded (like "sleep 1 | cat") */ + if (argv[0][0] == 'f' && G_saved_tty_pgrp) { + /* Put the job into the foreground. */ + tcsetpgrp(G_interactive_fd, pi->pgrp); + } + + /* Restart the processes in the job */ + debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp); + for (i = 0; i < pi->num_cmds; i++) { + debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid); + pi->cmds[i].is_stopped = 0; + } + pi->stopped_cmds = 0; + + i = kill(- pi->pgrp, SIGCONT); + if (i < 0) { + if (errno == ESRCH) { + delete_finished_bg_job(pi); + return EXIT_SUCCESS; + } + bb_perror_msg("kill (SIGCONT)"); + } + + if (argv[0][0] == 'f') { + remove_bg_job(pi); + return checkjobs_and_fg_shell(pi); + } + return EXIT_SUCCESS; +} +#endif + +#if ENABLE_HUSH_HELP +static int builtin_help(char **argv UNUSED_PARAM) +{ + const struct built_in_command *x; + + printf("\n" + "Built-in commands:\n" + "------------------\n"); + for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) { + printf("%s\t%s\n", x->cmd, x->descr); + } + printf("\n\n"); + return EXIT_SUCCESS; +} +#endif + +#if ENABLE_HUSH_JOB +static int builtin_jobs(char **argv UNUSED_PARAM) +{ + struct pipe *job; + const char *status_string; + + for (job = G.job_list; job; job = job->next) { + if (job->alive_cmds == job->stopped_cmds) + status_string = "Stopped"; + else + status_string = "Running"; + + printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext); + } + return EXIT_SUCCESS; +} +#endif + +#if HUSH_DEBUG +static int builtin_memleak(char **argv UNUSED_PARAM) +{ + void *p; + unsigned long l; + + /* Crude attempt to find where "free memory" starts, + * sans fragmentation. */ + p = malloc(240); + l = (unsigned long)p; + free(p); + p = malloc(3400); + if (l < (unsigned long)p) l = (unsigned long)p; + free(p); + + if (!G.memleak_value) + G.memleak_value = l; + + l -= G.memleak_value; + if ((long)l < 0) + l = 0; + l /= 1024; + if (l > 127) + l = 127; + + /* Exitcode is "how many kilobytes we leaked since 1st call" */ + return l; +} +#endif + +static int builtin_pwd(char **argv UNUSED_PARAM) +{ + puts(set_cwd()); + return EXIT_SUCCESS; +} + +static int builtin_read(char **argv) +{ + char *string; + const char *name = "REPLY"; + + if (argv[1]) { + name = argv[1]; + /* bash (3.2.33(1)) bug: "read 0abcd" will execute, + * and _after_ that_ it will complain */ + if (!is_well_formed_var_name(name, '\0')) { + /* Mimic bash message */ + bb_error_msg("read: '%s': not a valid identifier", name); + return 1; + } + } + +//TODO: bash unbackslashes input, splits words and puts them in argv[i] + + string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL); + return set_local_var(string, 0, 0); +} + +/* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set + * built-in 'set' handler + * SUSv3 says: + * set [-abCefhmnuvx] [-o option] [argument...] + * set [+abCefhmnuvx] [+o option] [argument...] + * set -- [argument...] + * set -o + * set +o + * Implementations shall support the options in both their hyphen and + * plus-sign forms. These options can also be specified as options to sh. + * Examples: + * Write out all variables and their values: set + * Set $1, $2, and $3 and set "$#" to 3: set c a b + * Turn on the -x and -v options: set -xv + * Unset all positional parameters: set -- + * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x" + * Set the positional parameters to the expansion of x, even if x expands + * with a leading '-' or '+': set -- $x + * + * So far, we only support "set -- [argument...]" and some of the short names. + */ +static int builtin_set(char **argv) { - char *p; - char *str = NULL; int n; - int len = 2; + char **pp, **g_argv; + char *arg = *++argv; + + if (arg == NULL) { + struct variable *e; + for (e = G.top_var; e; e = e->next) + puts(e->varstr); + return EXIT_SUCCESS; + } + + do { + if (!strcmp(arg, "--")) { + ++argv; + goto set_argv; + } + if (arg[0] != '+' && arg[0] != '-') + break; + for (n = 1; arg[n]; ++n) + if (set_mode(arg[0], arg[n])) + goto error; + } while ((arg = *++argv) != NULL); + /* Now argv[0] is 1st argument */ + + if (arg == NULL) + return EXIT_SUCCESS; + set_argv: + + /* NB: G.global_argv[0] ($0) is never freed/changed */ + g_argv = G.global_argv; + if (G.global_args_malloced) { + pp = g_argv; + while (*++pp) + free(*pp); + g_argv[1] = NULL; + } else { + G.global_args_malloced = 1; + pp = xzalloc(sizeof(pp[0]) * 2); + pp[0] = g_argv[0]; /* retain $0 */ + g_argv = pp; + } + /* This realloc's G.global_argv */ + G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1); + + n = 1; + while (*++pp) + n++; + G.global_argc = n; + + return EXIT_SUCCESS; + + /* Nothing known, so abort */ + error: + bb_error_msg("set: %s: invalid option", arg); + return EXIT_FAILURE; +} + +static int builtin_shift(char **argv) +{ + int n = 1; + if (argv[1]) { + n = atoi(argv[1]); + } + if (n >= 0 && n < G.global_argc) { + if (G.global_args_malloced) { + int m = 1; + while (m <= n) + free(G.global_argv[m++]); + } + G.global_argc -= n; + memmove(&G.global_argv[1], &G.global_argv[n+1], + G.global_argc * sizeof(G.global_argv[0])); + return EXIT_SUCCESS; + } + return EXIT_FAILURE; +} + +static int builtin_source(char **argv) +{ + const char *PATH; + FILE *input; + save_arg_t sv; +#if ENABLE_HUSH_FUNCTIONS + smallint sv_flg; +#endif + + if (*++argv == NULL) + return EXIT_FAILURE; + + if (strchr(*argv, '/') == NULL + && (PATH = get_local_var_value("PATH")) != NULL + ) { + /* Search through $PATH */ + while (1) { + const char *end = strchrnul(PATH, ':'); + int sz = end - PATH; /* must be int! */ + + if (sz != 0) { + char *tmp = xasprintf("%.*s/%s", sz, PATH, *argv); + input = fopen_for_read(tmp); + free(tmp); + } else { + /* We have xxx::yyyy in $PATH, + * it means "use current dir" */ + input = fopen_for_read(*argv); + } + if (input) + goto opened_ok; + if (*end == '\0') + break; + PATH = end + 1; + } + } + input = fopen_or_warn(*argv, "r"); + if (!input) { + /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */ + return EXIT_FAILURE; + } + opened_ok: + close_on_exec_on(fileno(input)); + +#if ENABLE_HUSH_FUNCTIONS + sv_flg = G.flag_return_in_progress; + /* "we are inside sourced file, ok to use return" */ + G.flag_return_in_progress = -1; +#endif + save_and_replace_G_args(&sv, argv); + + parse_and_run_file(input); + fclose(input); + + restore_G_args(&sv, argv); +#if ENABLE_HUSH_FUNCTIONS + G.flag_return_in_progress = sv_flg; +#endif - for (n = 0; inp[n]; n++) { - p = insert_var_value(inp[n]); - str = xrealloc(str, (len + strlen(p))); - if (n) { - strcat(str, " "); + return G.last_exitcode; +} + +static int builtin_umask(char **argv) +{ + int rc; + mode_t mask; + + mask = umask(0); + if (argv[1]) { + mode_t old_mask = mask; + + mask ^= 0777; + rc = bb_parse_mode(argv[1], &mask); + mask ^= 0777; + if (rc == 0) { + mask = old_mask; + /* bash messages: + * bash: umask: 'q': invalid symbolic mode operator + * bash: umask: 999: octal number out of range + */ + bb_error_msg("%s: '%s' invalid mode", argv[0], argv[1]); + } + } else { + rc = 1; + /* Mimic bash */ + printf("%04o\n", (unsigned) mask); + /* fall through and restore mask which we set to 0 */ + } + umask(mask); + + return !rc; /* rc != 0 - success */ +} + +/* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */ +static int builtin_unset(char **argv) +{ + int ret; + unsigned opts; + + /* "!": do not abort on errors */ + /* "+": stop at 1st non-option */ + opts = getopt32(argv, "!+vf"); + if (opts == (unsigned)-1) + return EXIT_FAILURE; + if (opts == 3) { + bb_error_msg("unset: -v and -f are exclusive"); + return EXIT_FAILURE; + } + argv += optind; + + ret = EXIT_SUCCESS; + while (*argv) { + if (!(opts & 2)) { /* not -f */ + if (unset_local_var(*argv)) { + /* unset <nonexistent_var> doesn't fail. + * Error is when one tries to unset RO var. + * Message was printed by unset_local_var. */ + ret = EXIT_FAILURE; + } + } +#if ENABLE_HUSH_FUNCTIONS + else { + unset_func(*argv); + } +#endif + argv++; + } + return ret; +} + +/* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */ +static int builtin_wait(char **argv) +{ + int ret = EXIT_SUCCESS; + int status, sig; + + if (*++argv == NULL) { + /* Don't care about wait results */ + /* Note 1: must wait until there are no more children */ + /* Note 2: must be interruptible */ + /* Examples: + * $ sleep 3 & sleep 6 & wait + * [1] 30934 sleep 3 + * [2] 30935 sleep 6 + * [1] Done sleep 3 + * [2] Done sleep 6 + * $ sleep 3 & sleep 6 & wait + * [1] 30936 sleep 3 + * [2] 30937 sleep 6 + * [1] Done sleep 3 + * ^C <-- after ~4 sec from keyboard + * $ + */ + sigaddset(&G.blocked_set, SIGCHLD); + sigprocmask(SIG_SETMASK, &G.blocked_set, NULL); + while (1) { + checkjobs(NULL); + if (errno == ECHILD) + break; + /* Wait for SIGCHLD or any other signal of interest */ + /* sigtimedwait with infinite timeout: */ + sig = sigwaitinfo(&G.blocked_set, NULL); + if (sig > 0) { + sig = check_and_run_traps(sig); + if (sig && sig != SIGCHLD) { /* see note 2 */ + ret = 128 + sig; + break; + } + } + } + sigdelset(&G.blocked_set, SIGCHLD); + sigprocmask(SIG_SETMASK, &G.blocked_set, NULL); + return ret; + } + + /* This is probably buggy wrt interruptible-ness */ + while (*argv) { + pid_t pid = bb_strtou(*argv, NULL, 10); + if (errno) { + /* mimic bash message */ + bb_error_msg("wait: '%s': not a pid or valid job spec", *argv); + return EXIT_FAILURE; + } + if (waitpid(pid, &status, 0) == pid) { + if (WIFSIGNALED(status)) + ret = 128 + WTERMSIG(status); + else if (WIFEXITED(status)) + ret = WEXITSTATUS(status); + else /* wtf? */ + ret = EXIT_FAILURE; } else { - *str = '\0'; + bb_perror_msg("wait %s", *argv); + ret = 127; + } + argv++; + } + + return ret; +} + +#if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS +static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min) +{ + if (argv[1]) { + def = bb_strtou(argv[1], NULL, 10); + if (errno || def < def_min || argv[2]) { + bb_error_msg("%s: bad arguments", argv[0]); + def = UINT_MAX; } - strcat(str, p); - len = strlen(str) + 3; - if (p != inp[n]) free(p); } - len = strlen(str); - *(str + len) = '\n'; - *(str + len + 1) = '\0'; - return str; + return def; } +#endif + +#if ENABLE_HUSH_LOOPS +static int builtin_break(char **argv) +{ + unsigned depth; + if (G.depth_of_loop == 0) { + bb_error_msg("%s: only meaningful in a loop", argv[0]); + return EXIT_SUCCESS; /* bash compat */ + } + G.flag_break_continue++; /* BC_BREAK = 1 */ + + G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1); + if (depth == UINT_MAX) + G.flag_break_continue = BC_BREAK; + if (G.depth_of_loop < depth) + G.depth_break_continue = G.depth_of_loop; + + return EXIT_SUCCESS; +} + +static int builtin_continue(char **argv) +{ + G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */ + return builtin_break(argv); +} +#endif + +#if ENABLE_HUSH_FUNCTIONS +static int builtin_return(char **argv) +{ + int rc; + + if (G.flag_return_in_progress != -1) { + bb_error_msg("%s: not in a function or sourced script", argv[0]); + return EXIT_FAILURE; /* bash compat */ + } + + G.flag_return_in_progress = 1; + + /* bash: + * out of range: wraps around at 256, does not error out + * non-numeric param: + * f() { false; return qwe; }; f; echo $? + * bash: return: qwe: numeric argument required <== we do this + * 255 <== we also do this + */ + rc = parse_numeric_argv1(argv, G.last_exitcode, 0); + return rc; +} +#endif |