Improved hddtemp agent module

I had some issues with the netcat / daemon implementation of the module.
netcat was stallingor sometimes netcat did not return the full output of hddtemp.
Running hddtemp directly without running it as a daemon is much more stable for me.

This new version also does not give any stdout output when hddtemp is not installed or when no disks can be found.
Running the script manually on a server does give stderr output for easy debugging.

agent-local/hddtemp

@@ -1,10 +1,35 @@
 #!/bin/bash
 
-# hddtemp sensor readings
-# needs hddtemp daemon listening on (at least) localhost
-# requires netcat to be installed and in the path
-# (c) 2012, Tom Laermans for Observium
+# LibreNMS agent to read HDD/SDD temperature using hddtemp
+#
+# Copyright (c) 2016 Exa-Omicron <http://exa.nl>
+#
+# This program is free software: you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation, either version 3 of the License, or (at your
+# option) any later version.  Please see LICENSE.txt at the top level of
+# the source code distribution for details.
+#
+# requires which, awk and sed
 
-echo '<<<hddtemp>>>'
-nc localhost 7634
-echo
+# If disks are missing, they can be added here:
+disks="/dev/hd? /dev/sd?"
+
+hddtemp=`which hddtemp 2>/dev/null`
+
+if [ "${hddtemp}" != "" ]; then
+	if [ -x "${hddtemp}" ]; then
+		content=`${hddtemp} -q ${disks} 2>/dev/null | awk -F": " 'BEGIN{ ORS="" }{ print "|"$1"|"$2"|"$3"|";} ' | sed 's/°/\|/g';`
+		if [ "${content}" != "" ]; then
+			echo '<<<hddtemp>>>'
+			echo ${content}
+			echo
+		else
+			echo "no hddtemp compatible disks found" >&2
+		fi
+	else
+		echo "hddtemp not executable" >&2
+	fi
+else
+	echo "hddtemp not installed" >&2
+fi