EXIT(2) BSD System Calls Manual EXIT(2)
_exit -- terminate the calling process
The _exit() function terminates a process with the following conse-
o All of the descriptors open in the calling process are closed. This
may entail delays, for example, waiting for output to drain; a
process in this state may not be killed, as it is already dying.
o If the parent process of the calling process has an outstanding wait
call or catches the SIGCHLD signal, it is notified of the calling
process's termination and the status is set as defined by wait(2).
o The parent process-ID of all of the calling process's existing child
processes are set to 1; the initialization process (see the DEFINI-
TIONS section of intro(2)) inherits each of these processes.
o If the termination of the process causes any process group to become
orphaned (usually because the parents of all members of the group
have now exited; see ``orphaned process group'' in intro(2)), and if
any member of the orphaned group is stopped, the SIGHUP signal and
the SIGCONT signal are sent to all members of the newly-orphaned
o If the process is a controlling process (see intro(2)), the SIGHUP
signal is sent to the foreground process group of the controlling
terminal, and all current access to the controlling terminal is
Most C programs call the library routine exit(3), which flushes buffers,
closes streams, unlinks temporary files, etc., before calling _exit().
_exit() can never return.
fork(2), sigaction(2), wait(2), exit(3)
The _exit function is defined by IEEE Std 1003.1-1988 (``POSIX.1'').
4th Berkeley Distribution June 4, 1993 4th Berkeley Distribution