From 016f3eef983cfe509272ce4b1a85864434ed308d Mon Sep 17 00:00:00 2001
From: millert <millert@openbsd.org>
Date: Thu, 30 Apr 2015 13:49:04 +0000
Subject: [PATCH] Add warning when user specifies -R but no files, like GNU
 grep. OK schwarze@ ian@

---
 usr.bin/grep/grep.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/usr.bin/grep/grep.c b/usr.bin/grep/grep.c
index f9fd3911ede..041d81ec9f8 100644
--- a/usr.bin/grep/grep.c
+++ b/usr.bin/grep/grep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: grep.c,v 1.50 2015/03/16 13:27:59 millert Exp $	*/
+/*	$OpenBSD: grep.c,v 1.51 2015/04/30 13:49:04 millert Exp $	*/
 
 /*-
  * Copyright (c) 1999 James Howard and Dag-Erling Coïdan Smørgrav
@@ -444,6 +444,8 @@ main(int argc, char *argv[])
 		++argv;
 	}
 
+	if (Rflag && argc == 0)
+		warnx("warning: recursive search of stdin");
 	if (Eflag)
 		cflags |= REG_EXTENDED;
 	if (Fflag)
-- 
2.20.1