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EXIT(3) FreeBSD Library Functions Manual EXIT(3)
NAME
exit, _Exit - perform normal program termination
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <stdlib.h>
void
exit(int status);
void
_Exit(int status);
DESCRIPTION
The exit() and _Exit() functions terminate a process.
Before termination, exit() performs the following functions in the order
listed:
1. Call all functions registered with the __cxa_atexit(3)
function (which are typically destructors from the loaded
dynamic objects), and the functions registered with the
atexit(3) function, in the reverse order of their
registration.
2. Flush all open output streams.
3. Close all open streams.
The _Exit() function terminates without calling the functions registered
with the atexit(3) function, and may or may not perform the other actions
listed. The FreeBSD implementation of the _Exit() function does not call
destructors registered with __cxa_atexit(3,) does not flush buffers, and
does not close streams.
Both functions make the low-order eight bits of the status argument
available to a parent process which has called a wait(2)-family function.
The C Standard (ISO/IEC 9899:1999 ("ISO C99")) defines the values 0,
EXIT_SUCCESS, and EXIT_FAILURE as possible values of status. Cooperating
processes may use other values; in a program which might be called by a
mail transfer agent, the values described in sysexits(3) may be used to
provide more information to the parent process.
Note that exit() does nothing to prevent bottomless recursion should a
function registered using atexit(3) itself call exit(). Such functions
must call _Exit() instead (although this has other effects as well which
may not be desired).
RETURN VALUES
The exit() and _Exit() functions never return.
SEE ALSO
_exit(2), abort2(2), wait(2), at_quick_exit(3), atexit(3), intro(3),
quick_exit(3), sysexits(3), tmpfile(3)
FreeBSD 14.0-RELEASE-p6 August 5, 2021 FreeBSD 14.0-RELEASE-p6