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 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.
sigintto the script and tosleep? (My guess is that this is what ctrl-c is doing).