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Diffstat (limited to 'release/src/router/busybox/coreutils/tail.c')
-rw-r--r--release/src/router/busybox/coreutils/tail.c311
1 files changed, 128 insertions, 183 deletions
diff --git a/release/src/router/busybox/coreutils/tail.c b/release/src/router/busybox/coreutils/tail.c
index 10b5cd7a..5dae2d35 100644
--- a/release/src/router/busybox/coreutils/tail.c
+++ b/release/src/router/busybox/coreutils/tail.c
@@ -4,20 +4,7 @@
*
* Copyright (C) 2001 by Matt Kraai <kraai@alumni.carnegiemellon.edu>
*
- * 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.
- *
- * 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.
- *
- * 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 GPLv2 or later, see file LICENSE in this tarball for details.
*/
/* BB_AUDIT SUSv3 compliant (need fancy for -c) */
@@ -37,303 +24,261 @@
* 7) lseek attempted when count==0 even if arg was +0 (from top)
*/
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <ctype.h>
-#include <unistd.h>
-#include <fcntl.h>
-#include <sys/stat.h>
-#include "busybox.h"
+#include "libbb.h"
static const struct suffix_mult tail_suffixes[] = {
{ "b", 512 },
{ "k", 1024 },
- { "m", 1048576 },
- { NULL, 0 }
+ { "m", 1024*1024 },
+ { }
};
-static int status
-#if EXIT_SUCCESS != 0
- = EXIT_SUCCESS /* If it is 0 (paranoid check), let bss initialize it. */
-#endif
- ;
+struct globals {
+ bool status;
+};
+#define G (*(struct globals*)&bb_common_bufsiz1)
static void tail_xprint_header(const char *fmt, const char *filename)
{
- /* If we get an output error, there is really no sense in continuing. */
- if (dprintf(STDOUT_FILENO, fmt, filename) < 0) {
- bb_perror_nomsg_and_die();
- }
-}
-
-/* len should probably be size_t */
-static void tail_xbb_full_write(const char *buf, size_t len)
-{
- /* If we get a write error, there is really no sense in continuing. */
- if (bb_full_write(STDOUT_FILENO, buf, len) < 0) {
+ if (fdprintf(STDOUT_FILENO, fmt, filename) < 0)
bb_perror_nomsg_and_die();
- }
}
static ssize_t tail_read(int fd, char *buf, size_t count)
{
ssize_t r;
-
- if ((r = safe_read(fd, buf, count)) < 0) {
- bb_perror_msg("read");
- status = EXIT_FAILURE;
+ off_t current;
+ struct stat sbuf;
+
+ /* (A good comment is missing here) */
+ current = lseek(fd, 0, SEEK_CUR);
+ /* /proc files report zero st_size, don't lseek them. */
+ if (fstat(fd, &sbuf) == 0 && sbuf.st_size)
+ if (sbuf.st_size < current)
+ lseek(fd, 0, SEEK_SET);
+
+ r = full_read(fd, buf, count);
+ if (r < 0) {
+ bb_perror_msg(bb_msg_read_error);
+ G.status = EXIT_FAILURE;
}
return r;
}
-static const char tail_opts[] =
- "fn:"
-#ifdef CONFIG_FEATURE_FANCY_TAIL
- "c:qs:v"
-#endif
- ;
+static const char header_fmt[] ALIGN1 = "\n==> %s <==\n";
-static const char header_fmt[] = "\n==> %s <==\n";
+static unsigned eat_num(const char *p)
+{
+ if (*p == '-')
+ p++;
+ else if (*p == '+') {
+ p++;
+ G.status = 1; /* mark that we saw "+" */
+ }
+ return xatou_sfx(p, tail_suffixes);
+}
+int tail_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int tail_main(int argc, char **argv)
{
- long count = 10;
- unsigned int sleep_period = 1;
- int from_top = 0;
- int follow = 0;
+ unsigned count = 10;
+ unsigned sleep_period = 1;
+ bool from_top;
int header_threshhold = 1;
-#ifdef CONFIG_FEATURE_FANCY_TAIL
- int count_bytes = 0;
-#endif
+ const char *str_c, *str_n;
char *tailbuf;
size_t tailbufsize;
int taillen = 0;
- int newline = 0;
+ int newlines_seen = 0;
+ int nfiles, nread, nwrite, i, opt;
+ unsigned seen;
- int *fds, nfiles, nread, nwrite, seen, i, opt;
+ int *fds;
char *s, *buf;
const char *fmt;
+#if ENABLE_INCLUDE_SUSv2 || ENABLE_FEATURE_FANCY_TAIL
/* Allow legacy syntax of an initial numeric option without -n. */
- if (argc >=2 && ((argv[1][0] == '+') || ((argv[1][0] == '-')
- /* && (isdigit)(argv[1][1]) */
- && (((unsigned int)(argv[1][1] - '0')) <= 9))))
- {
- optind = 2;
- optarg = argv[1];
- goto GET_COUNT;
+ if (argv[1] && (argv[1][0] == '+' || argv[1][0] == '-')
+ && isdigit(argv[1][1])
+ ) {
+ count = eat_num(argv[1]);
+ argv++;
+ argc--;
}
-
- while ((opt = getopt(argc, argv, tail_opts)) > 0) {
- switch (opt) {
- case 'f':
- follow = 1;
- break;
-#ifdef CONFIG_FEATURE_FANCY_TAIL
- case 'c':
- count_bytes = 1;
- /* FALLS THROUGH */
-#endif
- case 'n':
- GET_COUNT:
- count = bb_xgetlarg10_sfx(optarg, tail_suffixes);
- /* Note: Leading whitespace is an error trapped above. */
- if (*optarg == '+') {
- from_top = 1;
- } else {
- from_top = 0;
- }
- if (count < 0) {
- count = -count;
- }
- break;
-#ifdef CONFIG_FEATURE_FANCY_TAIL
- case 'q':
- header_threshhold = INT_MAX;
- break;
- case 's':
- sleep_period =bb_xgetularg10_bnd(optarg, 0, UINT_MAX);
- break;
- case 'v':
- header_threshhold = 0;
- break;
#endif
- default:
- bb_show_usage();
- }
- }
-
- /* open all the files */
- fds = (int *)xmalloc(sizeof(int) * (argc - optind + 1));
+ USE_FEATURE_FANCY_TAIL(opt_complementary = "s+";) /* -s N */
+ opt = getopt32(argv, "fc:n:" USE_FEATURE_FANCY_TAIL("qs:v"),
+ &str_c, &str_n USE_FEATURE_FANCY_TAIL(,&sleep_period));
+#define FOLLOW (opt & 0x1)
+#define COUNT_BYTES (opt & 0x2)
+ //if (opt & 0x1) // -f
+ if (opt & 0x2) count = eat_num(str_c); // -c
+ if (opt & 0x4) count = eat_num(str_n); // -n
+#if ENABLE_FEATURE_FANCY_TAIL
+ if (opt & 0x8) header_threshhold = INT_MAX; // -q
+ if (opt & 0x20) header_threshhold = 0; // -v
+#endif
+ argc -= optind;
argv += optind;
- nfiles = i = 0;
+ from_top = G.status; /* 1 if there was "-c +N" or "-n +N" */
+ G.status = EXIT_SUCCESS;
- if ((argc -= optind) == 0) {
+ /* open all the files */
+ fds = xmalloc(sizeof(int) * (argc + 1));
+ if (!argv[0]) {
struct stat statbuf;
if (!fstat(STDIN_FILENO, &statbuf) && S_ISFIFO(statbuf.st_mode)) {
- follow = 0;
+ opt &= ~1; /* clear FOLLOW */
}
- /* --argv; */
*argv = (char *) bb_msg_standard_input;
- goto DO_STDIN;
}
-
+ nfiles = i = 0;
do {
- if ((argv[i][0] == '-') && !argv[i][1]) {
- DO_STDIN:
- fds[nfiles] = STDIN_FILENO;
- } else if ((fds[nfiles] = open(argv[i], O_RDONLY)) < 0) {
- bb_perror_msg("%s", argv[i]);
- status = EXIT_FAILURE;
+ int fd = open_or_warn_stdin(argv[i]);
+ if (fd < 0) {
+ G.status = EXIT_FAILURE;
continue;
}
- argv[nfiles] = argv[i];
- ++nfiles;
+ fds[nfiles] = fd;
+ argv[nfiles++] = argv[i];
} while (++i < argc);
- if (!nfiles) {
+ if (!nfiles)
bb_error_msg_and_die("no files");
- }
+ /* prepare the buffer */
tailbufsize = BUFSIZ;
-#ifdef CONFIG_FEATURE_FANCY_TAIL
- /* tail the files */
- if (from_top < count_bytes) { /* Each is 0 or 1, so true iff 0 < 1. */
- /* Hence, !from_top && count_bytes */
- if (tailbufsize < count) {
+ if (!from_top && COUNT_BYTES) {
+ if (tailbufsize < count + BUFSIZ) {
tailbufsize = count + BUFSIZ;
}
}
-#endif
- buf = tailbuf = xmalloc(tailbufsize);
+ tailbuf = xmalloc(tailbufsize);
+ /* tail the files */
fmt = header_fmt + 1; /* Skip header leading newline on first output. */
i = 0;
do {
- /* Be careful. It would be possible to optimize the count-bytes
- * case if the file is seekable. If you do though, remember that
- * starting file position may not be the beginning of the file.
- * Beware of backing up too far. See example in wc.c.
- */
- if ((!(count|from_top)) && (lseek(fds[i], 0, SEEK_END) >= 0)) {
- continue;
- }
-
if (nfiles > header_threshhold) {
tail_xprint_header(fmt, argv[i]);
fmt = header_fmt;
}
+ /* Optimizing count-bytes case if the file is seekable.
+ * Beware of backing up too far.
+ * Also we exclude files with size 0 (because of /proc/xxx) */
+ if (COUNT_BYTES && !from_top) {
+ off_t current = lseek(fds[i], 0, SEEK_END);
+ if (current > 0) {
+ if (count == 0)
+ continue; /* showing zero lines is easy :) */
+ current -= count;
+ if (current < 0)
+ current = 0;
+ xlseek(fds[i], current, SEEK_SET);
+ bb_copyfd_size(fds[i], STDOUT_FILENO, count);
+ continue;
+ }
+ }
+
buf = tailbuf;
taillen = 0;
seen = 1;
-
+ newlines_seen = 0;
while ((nread = tail_read(fds[i], buf, tailbufsize-taillen)) > 0) {
if (from_top) {
nwrite = nread;
if (seen < count) {
-#ifdef CONFIG_FEATURE_FANCY_TAIL
- if (count_bytes) {
+ if (COUNT_BYTES) {
nwrite -= (count - seen);
seen = count;
- } else
-#endif
- {
+ } else {
s = buf;
do {
--nwrite;
- if ((*s++ == '\n') && (++seen == count)) {
+ if (*s++ == '\n' && ++seen == count) {
break;
}
} while (nwrite);
}
}
- tail_xbb_full_write(buf + nread - nwrite, nwrite);
+ xwrite(STDOUT_FILENO, buf + nread - nwrite, nwrite);
} else if (count) {
-#ifdef CONFIG_FEATURE_FANCY_TAIL
- if (count_bytes) {
+ if (COUNT_BYTES) {
taillen += nread;
- if (taillen > count) {
+ if (taillen > (int)count) {
memmove(tailbuf, tailbuf + taillen - count, count);
taillen = count;
}
- } else
-#endif
- {
+ } else {
int k = nread;
- int nbuf = 0;
+ int newlines_in_buf = 0;
- while (k) {
- --k;
+ do { /* count '\n' in last read */
+ k--;
if (buf[k] == '\n') {
- ++nbuf;
+ newlines_in_buf++;
}
- }
+ } while (k);
- if (newline + nbuf < count) {
- newline += nbuf;
+ if (newlines_seen + newlines_in_buf < (int)count) {
+ newlines_seen += newlines_in_buf;
taillen += nread;
-
} else {
- int extra = 0;
- if (buf[nread-1] != '\n') {
- extra = 1;
- }
+ int extra = (buf[nread-1] != '\n');
- k = newline + nbuf + extra - count;
+ k = newlines_seen + newlines_in_buf + extra - count;
s = tailbuf;
while (k) {
if (*s == '\n') {
- --k;
+ k--;
}
- ++s;
+ s++;
}
-
taillen += nread - (s - tailbuf);
memmove(tailbuf, s, taillen);
- newline = count - extra;
+ newlines_seen = count - extra;
}
- if (tailbufsize < taillen + BUFSIZ) {
+ if (tailbufsize < (size_t)taillen + BUFSIZ) {
tailbufsize = taillen + BUFSIZ;
tailbuf = xrealloc(tailbuf, tailbufsize);
}
}
buf = tailbuf + taillen;
}
- }
-
+ } /* while (tail_read() > 0) */
if (!from_top) {
- tail_xbb_full_write(tailbuf, taillen);
+ xwrite(STDOUT_FILENO, tailbuf, taillen);
}
-
- taillen = 0;
} while (++i < nfiles);
buf = xrealloc(tailbuf, BUFSIZ);
fmt = NULL;
- while (follow) {
+ if (FOLLOW) while (1) {
sleep(sleep_period);
i = 0;
do {
if (nfiles > header_threshhold) {
fmt = header_fmt;
}
- while ((nread = tail_read(fds[i], buf, sizeof(buf))) > 0) {
+ while ((nread = tail_read(fds[i], buf, BUFSIZ)) > 0) {
if (fmt) {
tail_xprint_header(fmt, argv[i]);
fmt = NULL;
}
- tail_xbb_full_write(buf, nread);
+ xwrite(STDOUT_FILENO, buf, nread);
}
} while (++i < nfiles);
}
-
- return status;
+ if (ENABLE_FEATURE_CLEAN_UP) {
+ free(fds);
+ }
+ return G.status;
}
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