You can get the pids of all child processes of a given parent process by reading the /proc//task//children entry. This file contain the pids of first level child processes.

Where is child processes of parent process in Linux?

if you want to see just the first-level children of a given parent process <pid> id look in /proc/<pid>/task/<tid>/children entry. Note that this file contains the pids of first-level child processes. for the whole process tree, do it recursively.

What is a child process in Linux?

A child process is a process created by a parent process in operating system using a fork() system call. A child process is created as its parent process’s copy and inherits most of its attributes. … If a child process has no parent process, it was created directly by the kernel.