*/
//kbuild:lib-$(CONFIG_TAIL) += tail.o
-//kbuild:lib-$(CONFIG_TAIL) += head_tail.o
//usage:#define tail_trivial_usage
//usage: "[OPTIONS] [FILE]..."
//usage: "Print last 10 lines of each FILE (or stdin) to stdout.\n"
//usage: "With more than one FILE, precede each with a filename header.\n"
//usage: "\n -f Print data as file grows"
-//usage: IF_FEATURE_FANCY_TAIL(
-//usage: "\n -s SECONDS Wait SECONDS between reads with -f"
-//usage: )
+//usage: "\n -c [+]N[kbm] Print last N bytes"
//usage: "\n -n N[kbm] Print last N lines"
//usage: "\n -n +N[kbm] Start on Nth line and print the rest"
//usage: IF_FEATURE_FANCY_TAIL(
-//usage: "\n -c [+]N[kbm] Print last N bytes"
//usage: "\n -q Never print headers"
+//usage: "\n -s SECONDS Wait SECONDS between reads with -f"
//usage: "\n -v Always print headers"
+//usage: "\n -F Same as -f, but keep retrying"
//usage: "\n"
//usage: "\nN may be suffixed by k (x1024), b (x512), or m (x1024^2)."
//usage: )
//usage: "nameserver 10.0.0.1\n"
#include "libbb.h"
-#include "head_tail.h"
struct globals {
bool from_top;
bb_perror_nomsg_and_die();
}
-static ssize_t tail_read(int fd, char *buf, size_t count, int follow)
+static ssize_t tail_read(int fd, char *buf, size_t count)
{
ssize_t r;
- if (follow) {
- /* tail -f keeps following files even if they are truncated */
- off_t current;
- struct stat sbuf;
-
- /* /proc files report zero st_size, don't lseek them */
- if (fstat(fd, &sbuf) == 0 && sbuf.st_size > 0) {
- current = lseek(fd, 0, SEEK_CUR);
- if (sbuf.st_size < current)
- xlseek(fd, 0, SEEK_SET);
- }
- }
-
r = full_read(fd, buf, count);
if (r < 0) {
bb_perror_msg(bb_msg_read_error);
p++;
G.from_top = 1;
}
- return xatou_sfx(p, head_tail_suffixes);
+ return xatou_sfx(p, bkm_suffixes);
}
int tail_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int *fds;
const char *fmt;
+ int prev_fd;
INIT_G();
* Used only by +N code ("start from Nth", 1-based): */
seen = 1;
newlines_seen = 0;
- while ((nread = tail_read(fd, buf, tailbufsize - taillen, /*follow:*/ 0)) > 0) {
+ while ((nread = tail_read(fd, buf, tailbufsize - taillen)) > 0) {
if (G.from_top) {
int nwrite = nread;
if (seen < count) {
xwrite(STDOUT_FILENO, tailbuf, taillen);
}
} while (++i < nfiles);
+ prev_fd = fds[i-1];
tailbuf = xrealloc(tailbuf, BUFSIZ);
if (nfiles > header_threshhold) {
fmt = header_fmt_str;
}
- while ((nread = tail_read(fd, tailbuf, BUFSIZ, /*follow:*/ 1)) > 0) {
- if (fmt) {
+ for (;;) {
+ /* tail -f keeps following files even if they are truncated */
+ struct stat sbuf;
+ /* /proc files report zero st_size, don't lseek them */
+ if (fstat(fd, &sbuf) == 0 && sbuf.st_size > 0) {
+ off_t current = lseek(fd, 0, SEEK_CUR);
+ if (sbuf.st_size < current)
+ xlseek(fd, 0, SEEK_SET);
+ }
+
+ nread = tail_read(fd, tailbuf, BUFSIZ);
+ if (nread <= 0)
+ break;
+ if (fmt && (fd != prev_fd)) {
tail_xprint_header(fmt, filename);
fmt = NULL;
+ prev_fd = fd;
}
xwrite(STDOUT_FILENO, tailbuf, nread);
}