_LONGJMP(P) POSIX Programmer's Manual _LONGJMP(P)
_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 unde-
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 termination. If the function has returned, the results are undefined.
Passing longjmp() a pointer to a buffer not created by setjmp(), passing _longjmp() a
pointer to a buffer not created by _setjmp(), passing siglongjmp() a pointer to a buffer
not created by sigsetjmp(), or passing 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 histor-
ical system interfaces. New applications should use siglongjmp() and sigsetjmp() respec-
The _longjmp() and _setjmp() functions may be marked LEGACY in a future version.
longjmp() , setjmp() , siglongjmp() , sigsetjmp() , the Base Definitions volume of
IEEE Std 1003.1-2001, <setjmp.h>
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 orig-
inal Standard can be obtained online at http://www.opengroup.org/unix/online.html .
IEEE/The Open Group 2003 _LONGJMP(P)