trusty (3) _setjmp.3posix.gz

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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 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 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 ALSO
       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
       original Standard can be obtained online at http://www.opengroup.org/unix/online.html .