diff options
Diffstat (limited to 'release/src/router/busybox/miscutils/dc.c')
| -rw-r--r-- | release/src/router/busybox/miscutils/dc.c | 187 |
1 files changed, 114 insertions, 73 deletions
diff --git a/release/src/router/busybox/miscutils/dc.c b/release/src/router/busybox/miscutils/dc.c index 5e367fe6..ff2bc3bc 100644 --- a/release/src/router/busybox/miscutils/dc.c +++ b/release/src/router/busybox/miscutils/dc.c @@ -1,21 +1,32 @@ /* vi: set sw=4 ts=4: */ -#include <ctype.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <unistd.h> +/* + * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. + */ + +#include "libbb.h" #include <math.h> -#include "busybox.h" /* Tiny RPN calculator, because "expr" didn't give me bitwise operations. */ -static double stack[100]; -static unsigned int pointer; -static unsigned char base; + +struct globals { + unsigned pointer; + unsigned base; + double stack[1]; +}; +enum { STACK_SIZE = (COMMON_BUFSIZE - offsetof(struct globals, stack)) / sizeof(double) }; +#define G (*(struct globals*)&bb_common_bufsiz1) +#define pointer (G.pointer ) +#define base (G.base ) +#define stack (G.stack ) +#define INIT_G() do { \ + base = 10; \ +} while (0) + static void push(double a) { - if (pointer >= (sizeof(stack) / sizeof(*stack))) + if (pointer >= STACK_SIZE) bb_error_msg_and_die("stack overflow"); stack[pointer++] = a; } @@ -44,6 +55,15 @@ static void mul(void) push(pop() * pop()); } +#if ENABLE_FEATURE_DC_LIBM +static void power(void) +{ + double topower = pop(); + + push(pow(pop(), topower)); +} +#endif + static void divide(void) { double divisor = pop(); @@ -51,46 +71,79 @@ static void divide(void) push(pop() / divisor); } +static void mod(void) +{ + unsigned d = pop(); + + push((unsigned) pop() % d); +} + static void and(void) { - push((unsigned int) pop() & (unsigned int) pop()); + push((unsigned) pop() & (unsigned) pop()); } static void or(void) { - push((unsigned int) pop() | (unsigned int) pop()); + push((unsigned) pop() | (unsigned) pop()); } static void eor(void) { - push((unsigned int) pop() ^ (unsigned int) pop()); + push((unsigned) pop() ^ (unsigned) pop()); } static void not(void) { - push(~(unsigned int) pop()); + push(~(unsigned) pop()); } static void set_output_base(void) { - base=(unsigned char)pop(); - if ((base != 10) && (base != 16)) { - fprintf(stderr, "Error: base = %d is not supported.\n", base); - base=10; + static const char bases[] ALIGN1 = { 2, 8, 10, 16, 0 }; + unsigned b = (unsigned)pop(); + + base = *strchrnul(bases, b); + if (base == 0) { + bb_error_msg("error, base %u is not supported", b); + base = 10; } } static void print_base(double print) { - if (base == 16) - printf("%x\n", (unsigned int)print); - else - printf("%g\n", print); + unsigned x, i; + + if (base == 10) { + printf("%g\n", print); + return; + } + + x = (unsigned)print; + switch (base) { + case 16: + printf("%x\n", x); + break; + case 8: + printf("%o\n", x); + break; + default: /* base 2 */ + i = (unsigned)INT_MAX + 1; + do { + if (x & i) break; + i >>= 1; + } while (i > 1); + do { + bb_putchar('1' - !(x & i)); + i >>= 1; + } while (i); + bb_putchar('\n'); + } } static void print_stack_no_pop(void) { - unsigned int i=pointer; + unsigned i = pointer; while (i) print_base(stack[--i]); } @@ -100,13 +153,8 @@ static void print_no_pop(void) print_base(stack[pointer-1]); } -static void print(void) -{ - print_base(pop()); -} - struct op { - const char *name; + const char name[4]; void (*function) (void); }; @@ -119,26 +167,32 @@ static const struct op operators[] = { {"mul", mul}, {"/", divide}, {"div", divide}, +#if ENABLE_FEATURE_DC_LIBM + {"**", power}, + {"exp", power}, + {"pow", power}, +#endif + {"%", mod}, + {"mod", mod}, {"and", and}, {"or", or}, {"not", not}, {"eor", eor}, + {"xor", eor}, {"p", print_no_pop}, {"f", print_stack_no_pop}, {"o", set_output_base}, - {0, 0} + { /* zero filled */ } }; static void stack_machine(const char *argument) { - char *endPointer = 0; + char *endPointer; double d; const struct op *o = operators; - if (argument == 0) { - print(); + if (argument == 0) return; - } d = strtod(argument, &endPointer); @@ -147,69 +201,56 @@ static void stack_machine(const char *argument) return; } - while (o->name != 0) { + while (o->name[0]) { if (strcmp(o->name, argument) == 0) { - (*(o->function)) (); + o->function(); return; } o++; } - bb_error_msg_and_die("%s: syntax error.", argument); + bb_error_msg_and_die("%s: syntax error", argument); } /* return pointer to next token in buffer and set *buffer to one char - * past the end of the above mentioned token + * past the end of the above mentioned token */ static char *get_token(char **buffer) { - char *start = NULL; - char *current = *buffer; - - while (isspace(*current)) { current++; } - if (*current != 0) { - start = current; - while (!isspace(*current) && current != 0) { current++; } - *buffer = current; + char *current = skip_whitespace(*buffer); + if (*current != '\0') { + *buffer = skip_non_whitespace(current); + return current; } - return start; + return NULL; } -/* In Perl one might say, scalar m|\s*(\S+)\s*|g */ -static int number_of_tokens(char *buffer) +int dc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +int dc_main(int argc UNUSED_PARAM, char **argv) { - int i = 0; - char *b = buffer; - while (get_token(&b)) { i++; } - return i; -} + INIT_G(); -int dc_main(int argc, char **argv) -{ - /* take stuff from stdin if no args are given */ - if (argc <= 1) { - int i, len; - char *line = NULL; - char *cursor = NULL; - char *token = NULL; - while ((line = bb_get_chomped_line_from_file(stdin))) { + argv++; + if (!argv[0]) { + /* take stuff from stdin if no args are given */ + char *line; + char *cursor; + char *token; + while ((line = xmalloc_fgetline(stdin)) != NULL) { cursor = line; - len = number_of_tokens(line); - for (i = 0; i < len; i++) { + while (1) { token = get_token(&cursor); - *cursor++ = 0; + if (!token) break; + *cursor++ = '\0'; stack_machine(token); } free(line); } } else { - if (*argv[1]=='-') + if (argv[0][0] == '-') bb_show_usage(); - while (argc >= 2) { - stack_machine(argv[1]); - argv++; - argc--; - } + do { + stack_machine(*argv); + } while (*++argv); } - stack_machine(0); return EXIT_SUCCESS; } |