tail -c 1 /dev/mtd3 hangs (v1.1.3)

[Steven Scholz]

Bernhard,

> How about using lseek() only for real files, i.e. (st_size > 0) and (st_rdev
> == 0) ?
> 
> What do you think of
> 
> static ssize_t tail_read(int fd, char *buf, size_t count)
> ...

Just in case you like it, attached a patch.

--
Steven
-------------- next part --------------
--- /home/stscholz/Temp/BUSYBOX/busybox-1.1.3/coreutils/tail.c	2006-03-22 22:16:21.000000000 +0100
+++ busybox-1.1.3/coreutils/tail.c	2006-06-22 09:42:52.000000000 +0200
@@ -65,10 +65,18 @@ static ssize_t tail_read(int fd, char *b
 	off_t current,end;
 	struct stat sbuf;
 
-	end = current = lseek(fd, 0, SEEK_CUR);
-	if (!fstat(fd, &sbuf))
+	if (fstat(fd, &sbuf) < 0) {
+		bb_perror_msg("fstat");
+		status = EXIT_FAILURE;
+		return 0;
+	}
+
+	if ( (sbuf.st_size > 0) && (sbuf.st_rdev == 0) ) {
 		end = sbuf.st_size;
-	lseek(fd, end < current ? 0 : current, SEEK_SET);
+		current = lseek(fd, 0, SEEK_CUR);
+		lseek(fd, end < current ? 0 : current, SEEK_SET);
+	}
+
 	if ((r = safe_read(fd, buf, count)) < 0) {
 		bb_perror_msg("read");
 		status = EXIT_FAILURE;