NAME

       setjmp - set jump point for a non-local goto

SYNOPSIS

       #include <setjmp.h>

       int setjmp(jmp_buf env);

DESCRIPTION

       A call to setjmp() shall save the calling environment in its env argument for later use by
       longjmp().

       It is unspecified whether setjmp() is a macro or a function.  If  a  macro  definition  is
       suppressed  in  order  to  access  an  actual  function,  or a program defines an external
       identifier with the name setjmp, the behavior is undefined.

       An application shall ensure that an invocation of setjmp() appears in one of the following
       contexts only:

        * The entire controlling expression of a selection or iteration statement

        * One  operand  of  a  relational or equality operator with the other operand an integral
          constant expression,  with  the  resulting  expression  being  the  entire  controlling
          expression of a selection or iteration statement

        * The  operand  of  a  unary  '!' operator with the resulting expression being the entire
          controlling expression of a selection or iteration

        * The entire expression of an expression statement (possibly cast to void)

       If the invocation appears in any other context, the behavior is undefined.

RETURN VALUE

       If the return is from a direct invocation, setjmp() shall return 0. If the return is  from
       a call to longjmp(), setjmp() shall return a non-zero value.

ERRORS

       No errors are defined.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       In  general,  sigsetjmp() is more useful in dealing with errors and interrupts encountered
       in a low-level subroutine of a program.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       longjmp() , sigsetjmp() , the Base Definitions 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 .