Bash Using "trap" to react to signals and system events Catching SIGINT or Ctl+C
Example
The trap is reset for subshells, so the sleep will still act on the SIGINT signal sent by ^C (usually by quitting), but the parent process (i.e. the shell script) won't.
#!/bin/sh
# Run a command on signal 2 (SIGINT, which is what ^C sends)
sigint() {
echo "Killed subshell!"
}
trap sigint INT
# Or use the no-op command for no output
#trap : INT
# This will be killed on the first ^C
echo "Sleeping..."
sleep 500
echo "Sleeping..."
sleep 500
And a variant which still allows you to quit the main program by pressing ^C twice in a second:
last=0
allow_quit() {
[ $(date +%s) -lt $(( $last + 1 )) ] && exit
echo "Press ^C twice in a row to quit"
last=$(date +%s)
}
trap allow_quit INT
