— terminate the calling
functions terminate a process with the following consequences:
- 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 catches the
SIGCHLDsignal, 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 these processes.
- 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
SIGCONTsignals are sent to all members of the newly orphaned process group.
- If the process is a controlling process (see
SIGHUPsignal 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., and then calls
_Exit() can never return.
fork(2), intro(2), sigaction(2), wait(2), exit(3), sysexits(3)
_exit() function conform to
IEEE Std 1003.1-2008 (“POSIX.1”). The
_Exit() function conforms to
exit() system call first appeared in
Version 1 AT&T UNIX. It accepts the
status argument since
Version 2 AT&T UNIX. An
_exit() variant first appeared in
Version 7 AT&T UNIX. The
_Exit() function appeared in