terminate the calling process
() functions terminate a process with the
- All threads in the process are terminated.
- All open file descriptors 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
SIGCHLD signal, it is
notified of the calling process's termination and
status is set as defined by
wait(2). (Note that typically
only the lower 8 bits of status are
passed on to the parent, thus negative values have less meaning.)
- The parent process ID of all of the calling process's
existing child processes are set to 1; the initialization process (see the
DEFINITIONS section of
intro(2)) inherits each of
- 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
SIGCONT signals are sent to all members
of the newly orphaned process group.
- If the process is a controlling process (see
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
, which flushes buffers,
closes streams, unlinks temporary files, etc., and then calls
() and _Exit
can never return.
() function conform to
IEEE Std 1003.1-2008
. The _Exit
function conforms to ISO/IEC 9899:1999
() system call first appeared in
Version 1 AT&T UNIX
. It accepts the
Version 2 AT&T UNIX
() variant first appeared in
Version 7 AT&T UNIX
() function appeared in