X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=coreutils%2Ftail.c;h=e352ab627b2e86b9e45c6ae59b1b17e4b0dd6ff1;hb=17f8418ea75410c3fbf9c9558f50f22cb8808e3e;hp=fb07ca27b840515b6af11a0722f6220c0149b461;hpb=6651e4260955d159e6a4f794d0a69c1b3f8e670c;p=oweals%2Fbusybox.git

diff --git a/coreutils/tail.c b/coreutils/tail.c
index fb07ca27b..e352ab627 100644
--- a/coreutils/tail.c
+++ b/coreutils/tail.c
@@ -25,7 +25,6 @@
  */
 
 //kbuild:lib-$(CONFIG_TAIL) += tail.o
-//kbuild:lib-$(CONFIG_TAIL) += head_tail.o
 
 //usage:#define tail_trivial_usage
 //usage:       "[OPTIONS] [FILE]..."
@@ -33,15 +32,14 @@
 //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:	)
@@ -51,7 +49,6 @@
 //usage:       "nameserver 10.0.0.1\n"
 
 #include "libbb.h"
-#include "head_tail.h"
 
 struct globals {
 	bool from_top;
@@ -66,23 +63,10 @@ static void tail_xprint_header(const char *fmt, const char *filename)
 		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);
@@ -102,7 +86,7 @@ static unsigned eat_num(const char *p)
 		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;
@@ -120,6 +104,7 @@ int tail_main(int argc, char **argv)
 
 	int *fds;
 	const char *fmt;
+	int prev_fd;
 
 	INIT_G();
 
@@ -255,7 +240,7 @@ int tail_main(int argc, char **argv)
 		 * 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) {
@@ -324,6 +309,7 @@ int tail_main(int argc, char **argv)
 			xwrite(STDOUT_FILENO, tailbuf, taillen);
 		}
 	} while (++i < nfiles);
+	prev_fd = fds[i-1];
 
 	tailbuf = xrealloc(tailbuf, BUFSIZ);
 
@@ -367,10 +353,23 @@ int tail_main(int argc, char **argv)
 			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);
 			}