setjmp(3p)
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 state
ment
- * One operand of a relational or equality operator with the other op
erand 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 nonzero 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 .