Add ptr bash command

README.md

@@ -44,6 +44,7 @@ Here's a list of the most interesting ones, along with what they do and where th
  - senddir - A small script I wrote to send whole directories over the network as a temporary thing. Uses netcat + gzip + tar.
  - recvdir - The counterpart to the above that receives the directory sent.
  - brightness.sh - Another small script I've written that controls the brightness of my screen. It works for me, but it may not work for you.
+ - ptr - A small script I wrote that uses `dig` to do PTR (reverse DNS) lookups, since I have to keep looking the command up every time :P
 
 ## Disclaimer
 I don't own many of the tools in this repository. If you are an owner of one of these tools and I haven't linked to you, please let me know as I probably forgot.

ptr

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+
+if [[ $# -ne 1 ]]; then
+	echo PTR lookup tool, by Starbeamrainbowlabs
+	echo Usage:
+	echo "    ptr x.y.z.w"
+	exit
+fi
+
+dig ptr $1.in-addr.arpa +short
+