This script gives you the ability to query your IRLP node's uptime from your DTMF keypad.  It can be downloaded here:

http://rob.pectol.com/irlp/scripts/uptime  

It uses a text to speech engine (Festival) to report back, in voice, how long your node has been up since the last reboot.  To make this work on your node, simply install Festival (do, "yum install festival" as root, without quotes) and then place my system uptime script (uptime) in your /home/irlp/custom directory.  It supports AUX line PTT for those nodes that are configured for it.  Simply open uptime in a text editor and modify the, "user configurable settings" near the top of it.  Then, make sure it is owned by user repeater and in group repeater.  Also make sure it is set executable (chmod 750 uptime).  At this point, you should be able to run it from the command line and have it announce your node's uptime!  If you want to be able to call this script from your DTMF keypad, simply add the following to your /home/irlp/custom/custom_decode file:

 # report the system uptime
if [ "$1" = "AA" ]; then
    $CUSTOM/uptime & >&/dev/null 2>&1
    exit 1
fi

This would cause the DTMF sequence, "AA" to call the uptime script.  Enjoy!