Trap Computer Shutdown Signal

[trent.josephsen]

And kill -TERM works as you expect? Does it behave the same way when you log out without shutting down, or does it continue running while you're logged out?

[dwhitney67]

Shell scripts are too high level to catch SIGTERM or SIGKILL. Maybe theres a way to do it, but I don't think trapping a signal will do it, seeing as the signal is sent to BASH/shell rather than your script. Unless BASH will relay this information to a shell script, which I don't think it does.

Wrong!

Here's an example script where SIGTERM is caught:

#!/bin/bash


trap dothis SIGTERM


function dothis()
{
   echo "Revert to original wallpaper here."
   exit 0
}

while [ true ]
do
   sleep 2
done

Run this script, then after referencing the PID of the script, issue a SIGTERM signal to it with something like:

kill -15 <pid>

# or

kill -s SIGTERM <pid>

To get a list of all of the signals that are recognized by Bash, run

trap -l

Obviously, as mentioned earlier, SIGKILL cannot be intercepted.

[Penguin Guy]

On a suspicion I googled traps and loops and found this page: http://tldp.org/LDP/Bash-Beginners-G...ect_12_02.html
It seems you need to add a wait statement if you want traps to work with loops, now I know what exactly the problem is it should be easy to fix it, so I'll mark this thread [SOLVED].

Thanks for all the help!