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.