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

       setjmp — set jump point for a non-local goto

SYNOPSIS

       #include <setjmp.h>

       int setjmp(jmp_buf env);

DESCRIPTION

       The functionality described on this reference page is aligned with the ISO C standard. Any
       conflict between the requirements described here and the ISO C standard is  unintentional.
       This volume of POSIX.1‐2008 defers to the ISO C standard.

       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 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  Electrical  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.kernel.org/doc/man-pages/reporting_bugs.html .