From: Paul Eggert <eggert@cs.ucla.edu>
Date: Fri, 14 Feb 2025 21:01:35 +0000 (-0800)
Subject: cat: omit unnecessary lseek
X-Git-Tag: v9.7~45
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=dff821d3e392d7ac39c44eb5ded43ea91ced92f2;p=thirdparty%2Fcoreutils.git

cat: omit unnecessary lseek

* src/cat.c (main): Don’t bother to try lseek on a fifo or socket,
as it will fail.
---

diff --git a/src/cat.c b/src/cat.c
index 92773d354f..274f844a16 100644
--- a/src/cat.c
+++ b/src/cat.c
@@ -712,7 +712,8 @@ main (int argc, char **argv)
          output device.  It's better to catch this error earlier
          rather than later.  */
 
-      if (! (S_TYPEISSHM (&stat_buf) || S_TYPEISTMO (&stat_buf))
+      if (! (S_ISFIFO (stat_buf.st_mode) || S_ISSOCK (stat_buf.st_mode)
+             || S_TYPEISSHM (&stat_buf) || S_TYPEISTMO (&stat_buf))
           && have_out_dev
           && stat_buf.st_dev == out_dev && stat_buf.st_ino == out_ino)
         {