From 87ec37621698d63cdfe3c98e8bd59c55e6abb443 Mon Sep 17 00:00:00 2001
From: David Xu <davidxu@FreeBSD.org>
Date: Tue, 22 Jan 2013 03:23:14 +0000
Subject: [PATCH] Make "-D skip" option work with FIFO by opening file in
 non-blocking mode.

Reviewed by:	jhb
Tested by:	delphij
---
 gnu/usr.bin/grep/grep.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/gnu/usr.bin/grep/grep.c b/gnu/usr.bin/grep/grep.c
index 1684a820b670..0cab4a18f28d 100644
--- a/gnu/usr.bin/grep/grep.c
+++ b/gnu/usr.bin/grep/grep.c
@@ -304,7 +304,7 @@ reset (int fd, char const *file, struct stats *stats)
   if (directories == SKIP_DIRECTORIES && S_ISDIR (stats->stat.st_mode))
     return 0;
 #ifndef DJGPP
-  if (devices == SKIP_DEVICES && (S_ISCHR(stats->stat.st_mode) || S_ISBLK(stats->stat.st_mode) || S_ISSOCK(stats->stat.st_mode)))
+  if (devices == SKIP_DEVICES && (S_ISCHR(stats->stat.st_mode) || S_ISBLK(stats->stat.st_mode) || S_ISSOCK(stats->stat.st_mode) || S_ISFIFO(stats->stat.st_mode)))
 #else
   if (devices == SKIP_DEVICES && (S_ISCHR(stats->stat.st_mode) || S_ISBLK(stats->stat.st_mode)))
 #endif
@@ -942,6 +942,7 @@ grepfile (char const *file, struct stats *stats)
   int desc;
   int count;
   int status;
+  int flags;
 
   if (! file)
     {
@@ -950,7 +951,7 @@ grepfile (char const *file, struct stats *stats)
     }
   else
     {
-      while ((desc = open (file, O_RDONLY)) < 0 && errno == EINTR)
+      while ((desc = open (file, O_RDONLY | O_NONBLOCK)) < 0 && errno == EINTR)
 	continue;
 
       if (desc < 0)
@@ -990,6 +991,9 @@ grepfile (char const *file, struct stats *stats)
 	  return 1;
 	}
 
+      flags = fcntl(desc, F_GETFL);
+      flags &= ~O_NONBLOCK;
+      fcntl(desc, F_SETFL, flags);
       filename = file;
     }