Editing Child process (section)

==Children created by fork==
A child process inherits most of its [[Attribute (computing)|attribute]]s, such as [[file descriptor]]s, from its parent. In [[Unix]], a child process is typically created as a copy of the parent, using the [[fork (system call)|fork]] system call. The child process can then overlay itself with a different program (using {{mono|[[Exec (system call)|exec]]}}) as required.<ref>{{FOLDOC|Child+process}}</ref>

Each process may create many child processes but will have at most one parent process; if a process does not have a parent this usually indicates that it was created directly by the [[kernel (operating system)|kernel]].  In some systems, including [[Linux kernel|Linux]]-based<!-- was an illiterate idiocy: Linux is not “Unix-based”--> systems, the very first process (called [[init]]) is started by the kernel at [[booting]] time and never terminates (see [[Linux startup process]]); other parentless processes may be launched to carry out various [[daemon (computing)|daemon]] tasks in [[userspace]].  Another way for a process to end up without a parent is if its parent dies, leaving an [[orphan process]]; but in this case it will shortly be adopted by ''init''.

The SIGCHLD [[Unix signal|signal]] is sent to the parent of a child process when it [[exit (system call)|exit]]s, is interrupted, or resumes after being interrupted. By default the signal is simply ignored.<ref>{{man|bd|signal.h|SUS}}</ref>