Child process

This technique pertains to multitasking operating systems, and is sometimes called a subprocess or traditionally a subtask.

Child processes date to the late 1960s, with an early form in later revisions of the Multiprogramming with a Fixed number of Tasks Version II (MFT-II) form of the IBM OS/360 operating system, which introduced sub-tasking (see task).

In Unix, a child process is typically created as a copy of the parent, using the fork system call.

Linux 2.6 kernels adhere to this behavior, and FreeBSD supports both of these methods since version 5.0.

[5] However, because of historical differences between System V and BSD behaviors with regard to ignoring SIGCHLD, calling wait remains the most portable paradigm for cleaning up after forked child processes.