Elegantly get list of children processes

Question

I would like to get a list of all the processes whose parent is $pid. This is the simplest way I've come up with:

pstree -p $pid | tr "\n" " " |sed "s/[^0-9]/ /g" |sed "s/\s\s*/ /g"

Is there any command, or any simpler way to get the list of children processes?

Thanks!

score 22 · Accepted Answer · answered Mar 12 '13 at 08:46

22

Yes, using the -P option of pgrep,

i.e pgrep -P 1234 will get you a list of child process ids.

answered Mar 12 '13 at 08:46

daisy

3

I'm afraid your answer is correct, but my question was incorrect. Therefore I accept your answer (which I didn't know, btw) and I opened another thread with the question I really meant to ask: http://unix.stackexchange.com/questions/67668/elegantly-get-list-of-descendant-processes – STenyaK Mar 12 '13 at 13:59

score 2 · Answer 2 · answered Aug 16 '20 at 03:42

2

pids of all child processes of a given parent process <pid> id is present in /proc/<pid>/task/<tid>/children entry.

This file contains the pids of first-level child processes. Do it recursively for whole process tree.

head over to https://lwn.net/Articles/475688/ for more information.

answered Aug 16 '20 at 03:42

y_159

1

Presence of the file is governed by `CONFIG_PROC_CHILDREN`. – Irfan Latif Mar 29 '21 at 07:24

2 Answers2