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-rw-r--r--coreutils/tail.c136
1 files changed, 48 insertions, 88 deletions
diff --git a/coreutils/tail.c b/coreutils/tail.c
index b690b370e..a753a10b7 100644
--- a/coreutils/tail.c
+++ b/coreutils/tail.c
@@ -29,44 +29,30 @@
static const struct suffix_mult tail_suffixes[] = {
{ "b", 512 },
{ "k", 1024 },
- { "m", 1048576 },
+ { "m", 1024*1024 },
{ NULL, 0 }
};
static int status;
-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 (full_write(STDOUT_FILENO, buf, len) < 0)
- bb_perror_nomsg_and_die();
-}
-
static void tail_xprint_header(const char *fmt, const char *filename)
{
-#if defined __GLIBC__
- if (dprintf(STDOUT_FILENO, fmt, filename) < 0) {
+ if (fdprintf(STDOUT_FILENO, fmt, filename) < 0)
bb_perror_nomsg_and_die();
- }
-#else
- int hdr_len = strlen(fmt) + strlen(filename);
- char *hdr = xzalloc(hdr_len);
- sprintf(hdr, filename, filename);
- tail_xbb_full_write(hdr, hdr_len);
-#endif
}
static ssize_t tail_read(int fd, char *buf, size_t count)
{
ssize_t r;
- off_t current,end;
+ off_t current, end;
struct stat sbuf;
end = current = lseek(fd, 0, SEEK_CUR);
if (!fstat(fd, &sbuf))
end = sbuf.st_size;
lseek(fd, end < current ? 0 : current, SEEK_SET);
- if ((r = safe_read(fd, buf, count)) < 0) {
+ r = safe_read(fd, buf, count);
+ if (r < 0) {
bb_perror_msg(bb_msg_read_error);
status = EXIT_FAILURE;
}
@@ -74,82 +60,55 @@ static ssize_t tail_read(int fd, char *buf, size_t count)
return r;
}
-static const char tail_opts[] =
- "fn:c:"
-#if ENABLE_FEATURE_FANCY_TAIL
- "qs:v"
-#endif
- ;
-
static const char header_fmt[] = "\n==> %s <==\n";
int tail_main(int argc, char **argv)
{
- long count = 10;
+ unsigned count = 10;
unsigned sleep_period = 1;
int from_top = 0;
- int follow = 0;
int header_threshhold = 1;
- int count_bytes = 0;
+ const char *str_c, *str_n, *str_s;
char *tailbuf;
size_t tailbufsize;
int taillen = 0;
int newline = 0;
+ int nfiles, nread, nwrite, seen, i, opt;
- int *fds, nfiles, nread, nwrite, seen, i, opt;
+ int *fds;
char *s, *buf;
const char *fmt;
+ void eat_num(const char *p) {
+ if (*p == '-') p++;
+ else if (*p == '+') { p++; from_top = 1; }
+ count = xatou_sfx(p, tail_suffixes);
+ }
+
+
#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])
) {
- optind = 2;
- optarg = argv[1];
- goto GET_COUNT;
+ argv[0] = "-n";
+ argv--;
+ argc++;
}
#endif
- while ((opt = getopt(argc, argv, tail_opts)) > 0) {
- switch (opt) {
- case 'f':
- follow = 1;
- break;
- case 'c':
- count_bytes = 1;
- /* FALLS THROUGH */
- case 'n':
-#if ENABLE_INCLUDE_SUSv2 || ENABLE_FEATURE_FANCY_TAIL
- GET_COUNT:
-#endif
- from_top = 0;
- if (*optarg == '+') {
- ++optarg;
- from_top = 1;
- }
- count = xatol_sfx(optarg, tail_suffixes);
- /* Note: Leading whitespace is an error trapped above. */
- if (count < 0) {
- count = -count;
- }
- break;
+ opt = getopt32(argc, argv, "fc:n:" USE_FEATURE_FANCY_TAIL("qs:v"), &str_c, &str_n, &str_s);
+#define FOLLOW (opt & 0x1)
+#define COUNT_BYTES (opt & 0x2)
+ //if (opt & 0x1) // -f
+ if (opt & 0x2) eat_num(str_c); // -c
+ if (opt & 0x4) eat_num(str_n); // -n
#if ENABLE_FEATURE_FANCY_TAIL
- case 'q':
- header_threshhold = INT_MAX;
- break;
- case 's':
- sleep_period = xatou(optarg);
- break;
- case 'v':
- header_threshhold = 0;
- break;
+ if (opt & 0x8) header_threshhold = INT_MAX; // -q
+ if (opt & 0x10) sleep_period = xatou(str_s); // -s
+ if (opt & 0x20) header_threshhold = 0; // -v
#endif
- default:
- bb_show_usage();
- }
- }
argc -= optind;
argv += optind;
@@ -160,34 +119,35 @@ int tail_main(int argc, char **argv)
struct stat statbuf;
if (!fstat(STDIN_FILENO, &statbuf) && S_ISFIFO(statbuf.st_mode)) {
- follow = 0;
+ opt &= ~1; /* clear FOLLOW */
}
*argv = (char *) bb_msg_standard_input;
goto DO_STDIN;
}
do {
- if (LONE_DASH(argv[i])) {
- DO_STDIN:
+ if (NOT_LONE_DASH(argv[i])) {
+ fds[nfiles] = open(argv[i], O_RDONLY);
+ if (fds[nfiles] < 0) {
+ bb_perror_msg("%s", argv[i]);
+ status = EXIT_FAILURE;
+ continue;
+ }
+ } else {
+ 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;
- continue;
}
argv[nfiles] = argv[i];
++nfiles;
} while (++i < argc);
- if (!nfiles) {
+ if (!nfiles)
bb_error_msg_and_die("no files");
- }
tailbufsize = BUFSIZ;
/* tail the files */
- if (from_top < count_bytes) { /* Each is 0 or 1, so true iff 0 < 1. */
- /* Hence, !from_top && count_bytes */
+ if (!from_top && COUNT_BYTES) {
if (tailbufsize < count) {
tailbufsize = count + BUFSIZ;
}
@@ -203,7 +163,7 @@ int tail_main(int argc, char **argv)
* 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)) {
+ if (!(count|from_top) && lseek(fds[i], 0, SEEK_END) >= 0) {
continue;
}
@@ -221,22 +181,22 @@ int tail_main(int argc, char **argv)
if (from_top) {
nwrite = nread;
if (seen < count) {
- if (count_bytes) {
+ if (COUNT_BYTES) {
nwrite -= (count - seen);
seen = count;
} 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) {
- if (count_bytes) {
+ if (COUNT_BYTES) {
taillen += nread;
if (taillen > count) {
memmove(tailbuf, tailbuf + taillen - count, count);
@@ -286,7 +246,7 @@ int tail_main(int argc, char **argv)
}
if (!from_top) {
- tail_xbb_full_write(tailbuf, taillen);
+ xwrite(STDOUT_FILENO, tailbuf, taillen);
}
taillen = 0;
@@ -296,7 +256,7 @@ int tail_main(int argc, char **argv)
fmt = NULL;
- while (follow) {
+ if (FOLLOW) while (1) {
sleep(sleep_period);
i = 0;
do {
@@ -308,7 +268,7 @@ int tail_main(int argc, char **argv)
tail_xprint_header(fmt, argv[i]);
fmt = NULL;
}
- tail_xbb_full_write(buf, nread);
+ xwrite(STDOUT_FILENO, buf, nread);
}
} while (++i < nfiles);
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-30 07:52:03 +0000