_exit(2) - NetBSD Manual Pages

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EXIT(2)                   NetBSD System Calls Manual                   EXIT(2)


NAME

     _Exit, _exit -- terminate the calling process


LIBRARY

     Standard C Library (libc, -lc)


SYNOPSIS

     #include <stdlib.h>

     void
     _Exit(int status);

     #include <unistd.h>

     void
     _exit(int status);


DESCRIPTION

     The _Exit() and _exit() functions are equivalent.  They each terminate 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).  (Note that only the least significant 8 bits of status are
         preserved and returned to the parent via wait(2).)

     ·   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.

     ·   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

     _Exit() and _exit() can never return.


SEE ALSO

     fork(2), sigaction(2), wait(2), exit(3)


STANDARDS

     The _exit() function conforms to ISO/IEC 9945-1:1990 (``POSIX.1'').  The
     _Exit() function conforms to ISO/IEC 9899:1999 (``ISO C99'').

NetBSD 10.1                    October 17, 2022                    NetBSD 10.1