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For example, while I am running the script below, if I send an INT signal with Ctrl + C, the script file gets interrupted immediately. But when I try the same process with the kill command as kill -2 pid, the sleep command is expected to finish for the interrupt signal to be valid. What exactly is the reason for this situation?

#!/bin/bash

trap 'echo signal received!!' SIGINT

echo "The script pid is $$"
sleep 30
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  • @ctrl-alt-delor You are right, i fixed now.
    – testter
    Oct 23, 2020 at 16:59
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    What happens if you send sigint to the script and to sleep? (My guess is that this is what ctrl-c is doing).
    – ctrl-alt-delor
    Oct 23, 2020 at 17:05
  • @ctrl-alt-delor I would like to thank you for taking your precious time and returning to the questions I asked.
    – testter
    Oct 23, 2020 at 17:48

1 Answer 1

Reset to default
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The difference is that when you press Ctrl-C the kernel will send a SIGINT signal to both your script and the sleep command (i.e. it will send the signal to the whole process group), but with kill -INT $pid you're only signaling $pid (supposedly your script).

Assuming that your script is started from a typical interactive shell (i.e. the script is the process group leader), just negating the pid should work: kill -INT -$pid.

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