initial

tmux/powerline/lib/arg_processing.sh

@@ -0,0 +1,9 @@
+#! Check script arguments.
+
+check_arg_side() {
+	local side="$1"		
+	if ! [ "$side" ==  "left" -o "$side" == "right" ]; then
+		echo "Argument must be the side to handle {left, right} and not \"${side}\"."
+    	exit 1
+	fi
+}