tail: code shrink

function                                             old     new   delta
tail_main                                           1548    1613     +65
tail_read                                            136      34    -102
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/1 up/down: 65/-102)           Total: -37 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 15 insertions, 16 deletions

diff --git a/coreutils/tail.c b/coreutils/tail.c
index fb07ca2..c9f9d00 100644
--- a/coreutils/tail.c
+++ b/coreutils/tail.c
@@ -66,23 +66,10 @@ 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);
@@ -255,7 +242,7 @@ 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) {
@@ -367,7 +354,19 @@ 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) {
+			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) {
 					tail_xprint_header(fmt, filename);
 					fmt = NULL;