You can setup a loop that runs in the background to periodically execute "sudo -v", the trick of course is getting the loop to cleanly terminate when your script terminates. So there has to be some type of communication between the two processes; tmp files are fine for this, and they can easily be cleaned up after the script runs, too. (An install script usually does this, anyway.)
For example (remove the 'echo' statements to use this; these just show it "working"):
#!/bin/bash
log=running_setup.txt
sudo_stat=sudo_status.txt
echo "========= running script $$ ========"
echo $$ >> $sudo_stat
trap 'rm -f $sudo_stat >/dev/null 2>&1' 0
trap "exit 2" 1 2 3 15
sudo_me() {
while [ -f $sudo_stat ]; do
echo "checking $$ ...$(date)"
sudo -v
sleep 5
done &
}
echo "=setting up sudo heartbeat="
sudo -v
sudo_me
echo "=running setup=" | tee $log
while [ -f $log ]
do
echo "running setup $$ ...$(date) ===" | tee -a $log
sleep 2
done
# finish sudo loop
rm $sudo_stat
Then you'll see... (note: the pid is put into the tmp file, just so you can easily kill it. It's not necessary, though):
$ ./do_it.sh
========= running script 6776 ========
=setting up sudo heartbeat=
[sudo] password for user:
=running setup=
checking 6776 ...Wed May 4 16:31:47 PDT 2011
running setup 6776 ...Wed May 4 16:31:48 PDT 2011 ===
running setup 6776 ...Wed May 4 16:31:50 PDT 2011 ===
running setup 6776 ...Wed May 4 16:31:52 PDT 2011 ===
checking 6776 ...Wed May 4 16:31:53 PDT 2011
running setup 6776 ...Wed May 4 16:31:54 PDT 2011 ===
<ctrl-c> (cleans up files, then exits)