_LONGJMP(3P) POSIX Programmer's Manual _LONGJMP(3P)PROLOG
This manual page is part of the POSIX Programmer's Manual. The Linux
implementation of this interface may differ (consult the corresponding
Linux manual page for details of Linux behavior), or the interface may
not be implemented on Linux.
_longjmp, _setjmp — non-local goto
void _longjmp(jmp_buf env, int val);
int _setjmp(jmp_buf env);
The _longjmp() and _setjmp() functions shall be equivalent to longjmp()
and setjmp(), respectively, with the additional restriction that
_longjmp() and _setjmp() shall not manipulate the signal mask.
If _longjmp() is called even though env was never initialized by a call
to _setjmp(), or when the last such call was in a function that has
since returned, the results are undefined.
Refer to longjmp() and setjmp().
No errors are defined.
The following sections are informative.
If _longjmp() is executed and the environment in which _setjmp() was
executed no longer exists, errors can occur. The conditions under which
the environment of the _setjmp() no longer exists include exiting the
function that contains the _setjmp() call, and exiting an inner block
with temporary storage. This condition might not be detectable, in
which case the _longjmp() occurs and, if the environment no longer
exists, the contents of the temporary storage of an inner block are
unpredictable. This condition might also cause unexpected process ter‐
mination. If the function has returned, the results are undefined.
Passing longjmp() a pointer to a buffer not created by setjmp(), pass‐
ing _longjmp() a pointer to a buffer not created by _setjmp(), passing
siglongjmp() a pointer to a buffer not created by sigsetjmp(), or pass‐
ing any of these three functions a buffer that has been modified by the
user can cause all the problems listed above, and more.
The _longjmp() and _setjmp() functions are included to support programs
written to historical system interfaces. New applications should use
siglongjmp() and sigsetjmp() respectively.
The _longjmp() and _setjmp() functions may be removed in a future ver‐
SEE ALSOlongjmp(), setjmp(), siglongjmp(), sigsetjmp()
The Base Definitions volume of POSIX.1‐2008, <setjmp.h>
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
cal and Electronics Engineers, Inc and The Open Group. (This is
POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online
at http://www.unix.org/online.html .
Any typographical or formatting errors that appear in this page are
most likely to have been introduced during the conversion of the source
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IEEE/The Open Group 2013 _LONGJMP(3P)