From c21685c13ec40e6060ab7252e1bf458de67676a6 Mon Sep 17 00:00:00 2001
From: "Eric D. Kjeldergaard" <kjelderg@iteris.com>
Date: Thu, 17 Apr 2014 17:50:39 -0500
Subject: [PATCH] Grep version check for exclude argument format

Make some updates inspired by ncancelll's comments.
---
 lib/grep.zsh | 34 ++++++++++++++++++++++++++++++----
 1 file changed, 30 insertions(+), 4 deletions(-)

diff --git a/lib/grep.zsh b/lib/grep.zsh
index 977435ee4..391490489 100644
--- a/lib/grep.zsh
+++ b/lib/grep.zsh
@@ -3,11 +3,37 @@
 # Examples: http://rubyurl.com/ZXv
 #
 
-# avoid VCS folders
 GREP_OPTIONS=
-for PATTERN in .cvs .git .hg .svn; do
-    GREP_OPTIONS+="--exclude-dir=$PATTERN "
-done
+
+# returns 0 if the first version number is greater than or equal to the second.
+# returns 1 if the first version number is greater than or equal to the second.
+function versionCompare() {
+	local LEAST_VERSION=$(echo -e "$1\n$2" | sort -t '.' -g | head -n 1)
+	if [[ $LEAST_VERSION = $1 ]]; then
+		return 0
+	fi
+	return 1
+}
+
+# avoid VCS folders.  This chooses a different argument based on grep version.
+# grep version 2.5+ is required for any support of this feature.
+function ignoreVCS() {
+	local GREP_VERSION=$(grep --version | head -n 1 | sed -e 's/^.* \([0-9]\{1,\}\(\.[0-9a-z]\{1,\}\)\{1,\}\)-.*/\1/')
+
+	for PATTERN in .cvs .git .hg .svn; do
+		# logically, if(GREP_VERSION >= 2.5.3)
+		if versionCompare "2.5.3" $GREP_VERSION; then
+			GREP_OPTIONS+="--exclude-dir=$PATTERN "
+		# logically, if(GREP_VERSION >= 2.5)
+		elif versionCompare "2.5" $GREP_VERSION; then
+			GREP_OPTIONS+="--exclude=$PATTERN "
+		fi
+	done
+}
+ignoreVCS;
+unfunction versionCompare
+unfunction ignoreVCS
+
 GREP_OPTIONS+="--color=auto"
 export GREP_OPTIONS="$GREP_OPTIONS"
 export GREP_COLOR='1;32'