From: Paul Eggert <eggert@cs.ucla.edu>
Date: Thu, 22 Jul 2004 20:54:04 +0000 (+0000)
Subject: (main): Ignore -f if no file operand is specified
X-Git-Tag: v5.3.0~1113
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=255eb9cf44100e5fbd269e7ccf04faafb0c38f73;p=thirdparty%2Fcoreutils.git

(main): Ignore -f if no file operand is specified
and standard input is a pipe.
---

diff --git a/src/tail.c b/src/tail.c
index b6bd04ae16..5e7d9b3698 100644
--- a/src/tail.c
+++ b/src/tail.c
@@ -1687,6 +1687,15 @@ main (int argc, char **argv)
       static char *dummy_stdin = "-";
       n_files = 1;
       file = &dummy_stdin;
+
+      /* POSIX says that -f is ignored if no file operand is specified
+	 and standard input is a pipe.  */
+      if (forever)
+	{
+	  struct stat stats;
+	  if (fstat (STDIN_FILENO, &stats) == 0 && S_ISFIFO (stats.st_mode))
+	    forever = false;
+	}
     }
 
   {