From 32b5bb9661864905fdb1f99a0dc4cf553034157a Mon Sep 17 00:00:00 2001
From: paul <paul@plutz.net>
Date: Mon, 5 Oct 2015 23:40:50 +0000
Subject: [PATCH 1/1] added invalidate function

svn path=/trunk/; revision=17
---
 misc.sh | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/misc.sh b/misc.sh
index 05a3af5..9d92805 100755
--- a/misc.sh
+++ b/misc.sh
@@ -38,3 +38,15 @@ validate(){
   printf %s\\n "${value}" \
   | sed -rn "2q; /^(${regex})\$/{p;q}; a${default}"
 }
+
+invalidate(){
+  # print default if value matches regex; otherwise print value
+  value="$1"
+  regex="$(printf %s\\n "$2" \
+           | sed -r 's;(^|[^\\]+)((\\\\)+)/;\1\2\\/;g; s;(^|[^\\])/;\1\\/;g; s;(^|[^\\]+)((\\\\)+)/;\1\2\\/;g; s;(^|[^\\])/;\1\\/;g;'
+          )" # ^^ escape only unescaped slash characters for later insertion
+  default="$3"
+
+  printf %s\\n "${value}" \
+  | sed -rn "2q; /^(${regex})\$/{bd}; p;q; :d;a${default}"
+}
-- 
2.39.2