From c00dc78f30a1655c3c3e1576a909794f8df3135f Mon Sep 17 00:00:00 2001
From: Peter Packult <Peter.Packult@priveasy.de>
Date: Fri, 9 Sep 2011 20:15:42 +0200
Subject: [PATCH] Initial commit

---
 README.org                |  2 ++
 src/update_hacker_density | 17 +++++++++++++++++
 2 files changed, 19 insertions(+)
 create mode 100644 README.org
 create mode 100755 src/update_hacker_density

diff --git a/README.org b/README.org
new file mode 100644
index 0000000..fcfb030
--- /dev/null
+++ b/README.org
@@ -0,0 +1,2 @@
+Send MAC addrs of all current DHCP leases to <TODO>. Transmit only if
+the list changed since last transmission.
diff --git a/src/update_hacker_density b/src/update_hacker_density
new file mode 100755
index 0000000..6319f52
--- /dev/null
+++ b/src/update_hacker_density
@@ -0,0 +1,17 @@
+#!/bin/sh
+
+LeaseFile=/tmp/dhcp.leases
+TmpFile=/tmp/hackers
+StateFile=/tmp/hackers.md5
+Hash=md5sum
+
+awk '{ if ($1 > '$(date +%s)') print $2 }' < $LeaseFile > $TmpFile
+OldHash=$(cat $StateFile 2>/dev/null)
+NewHash=$($Hash $TmpFile | cut -f1 -d" ")
+if [ "$OldHash" != "$NewHash" ]; then
+	# send new state, update local state only if transmission was succesful
+	(	echo Es sind $(wc -l <$TmpFile) Hacker im Space:
+		cat $TmpFile) \
+	|  nc -c feinsterfug.de 666 \
+	&& echo "$NewHash" > $StateFile
+fi