_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.

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 removed in a future  ver‐
       sion.

SEE ALSO
       longjmp(), setjmp(), siglongjmp(), sigsetjmp()

       The Base Definitions volume of POSIX.1‐2008, <setjmp.h>

COPYRIGHT
       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
       files to man page format. To report such errors,	 see  https://www.ker‐
       nel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group		     2013			  _LONGJMP(3P)

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