run script for X mins

mitchell2345 · 06-16-2009, 04:31 PM

hi,

I am recording off my firewire port. Long story but i cant get Mythtv to work yet. I can use test-mpeg2 -r 1 > file.ts. this just dumps the video to disk

How can i create a crontab/script that will run that cmd for a specified time period

ie, start cmd and 22:00 stop at 22:30

Thanks,
Mitchell

Trumpen · 06-16-2009, 05:08 PM

You can create a script like this:

Code:

#!/bin/bash

command &

sleep 1800 # 30*60 seconds

kill $! # $! contains PID of the last background executed process

If you need more precision you can use a while loop instead of sleep:

Code:

#!/bin/bash

end=$(date -d "+30 minutes" '+%s')

command &

while [ "$(date '+%s')" -lt "$end" ]; do
       sleep 1;
done

kill $!