_LONGJMP(P) POSIX Programmer's Manual _LONGJMP(P)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.
NAME
_longjmp, _setjmp - non-local goto
SYNOPSIS
#include <setjmp.h>
void _longjmp(jmp_buf env, int val);
int _setjmp(jmp_buf env);
DESCRIPTION
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.
RETURN VALUE
Refer to longjmp() and setjmp() .
ERRORS
No errors are defined.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
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.
RATIONALE
None.
FUTURE DIRECTIONS
The _longjmp() and _setjmp() functions may be marked LEGACY in a future
version.
SEE ALSOlongjmp() , setjmp() , siglongjmp() , sigsetjmp() , the Base Defini‐
tions volume of IEEE Std 1003.1-2001, <setjmp.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. 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.opengroup.org/unix/online.html .
IEEE/The Open Group 2003 _LONGJMP(P)
