From dff821d3e392d7ac39c44eb5ded43ea91ced92f2 Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Fri, 14 Feb 2025 13:01:35 -0800
Subject: [PATCH] cat: omit unnecessary lseek
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* src/cat.c (main): Don’t bother to try lseek on a fifo or socket,
as it will fail.
---
 src/cat.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

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)
         {
-- 
2.47.3