keyfunc.sh: Protect arguments to expr(1).

Make sure they don't look like operators or functions.

diff --git a/keyfunc.sh.in b/keyfunc.sh.in
index 38ca243fe7ff31a6e7de1d920e27f8aa2a217876..2a10f267a46fdc3d69d434b181543fd7f6fbdd8b 100644 (file)
--- a/keyfunc.sh.in
+++ b/keyfunc.sh.in
@@ -144,7 +144,7 @@ check () {
   validp=t
   case "$thing" in
     *"$nl"*) validp=nil ;;
-    *) if ! expr >/dev/null "$thing" : "$ckpat\$"; then validp=nil; fi ;;
+    *) if ! expr >/dev/null "Q$thing" : "Q$ckpat\$"; then validp=nil; fi ;;
   esac
   case $validp in
     nil) echo >&2 "$quis: bad $ckwhat \`$thing'"; exit 1 ;;