Restore the read_yesno_with_timeout() function

Signed-off-by: Tom Eastep <teastep@shorewall.net>

Shorewall/lib.cli-std

@@ -1063,6 +1063,41 @@ restart_command() {
     return $rc
 }
 
+read_yesno_with_timeout() {
+    local timeout
+    timeout=${1:-60}
+
+    case $timeout in
+	*s)
+	    ;;
+	*m)
+	    timeout=$((${timeout%m} * 60))
+	    ;;
+	*h)
+	    timeout=$((${timeout%h} * 3600))
+	    ;;
+    esac
+
+    read -t $timeout yn 2> /dev/null
+    if [ $? -eq 2 ]
+    then
+	# read doesn't support timeout
+	test -x /bin/bash || return 2 # bash is not installed so the feature is not available
+	/bin/bash -c "read -t $timeout yn ; if [ \"\$yn\" == \"y\" ] ; then exit 0 ; else exit 1 ; fi" # invoke bash and use its version of read
+	return $?
+    else
+	# read supports timeout
+	case "$yn" in
+	    y|Y)
+		return 0
+		;;
+	    *)
+		return 1
+		;;
+	esac
+    fi
+}
+
 #
 # Safe-start/safe-reload/safe-restart Command Executor
 #