How to set process group of a shell script

Question

How to set process group of a shell script ? Also I want all the child process to be in the same process group

I expect something similar to setpgid() in C.

Answer 1

I don't think Bourne, bash, or zsh will let you do that, but you could do it in perl using the built-in setpgrp (note the slight name difference from POSIX). Pass zero as the PID to modify the group of the perl process itself:

setpgrp(0, 12345) || die "$!"

You might think you could use perl from, say, bash to set the bash process's group (by passing $$ to a perl script, for example), but I don't think the perl process would be able to modify the group of a process that it didn't fork.

Depending on what you're trying to do, the job control features in various shells may give you what you need, in a different way, like if you just want to detach from the terminal.

UPDATE: I think it's strange that this answer has received a couple of down-votes without clear explanation why. My guess is that the downvoters are misunderstanding the question, which is asking how to change the process group of the current shell. Or perhaps they know how to do a setpgrp from the shell but are keeping the secret to themselves.