NAME
_exit - terminate the calling process
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <unistd.h>
void
_exit(int status);
DESCRIPTION
The _exit() system call terminates a process with the following
consequences:
· 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.
· If the parent process of the calling process has an outstanding
wait(2) 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).
· The parent process-ID of all of the calling process’s existing child
processes are set to 1; the initialization process inherits each of
these processes (see init(8) and the DEFINITIONS section of
intro(2)).
· 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
process group.
· 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
revoked.
Most C programs call the library routine exit(3), which flushes buffers,
closes streams, unlinks temporary files, etc., before calling _exit().
RETURN VALUES
The _exit() system call can never return.
SEE ALSO
fork(2), sigaction(2), wait(2), exit(3), init(8)
STANDARDS
The _exit() system call is expected to conform to ISO/IEC 9945-1:1990
(“POSIX.1”).
HISTORY
The _exit() function appeared in Version 7 AT&T UNIX.