NAME
longjmp, siglongjmp - non-local jump to a saved stack con-
text
SYNOPSIS
#include <setjmp.h>
void longjmp(jmp_buf env, int val));
void siglongjmp(sigjmp_buf env, int val));
DESCRIPTION
longjmp() and setjmp() are useful for dealing with errors
and interrupts encountered in a low-level subroutine of a
program. longjmp() restores the environment saved by the
last call of setjmp() with the corresponding env argument.
After longjmp() is completed, program execution continues as
if the corresponding call of setjmp() had just returned the
value val. longjmp() cannot cause 0 to be returned. If
longjmp is invoked with a second argument of 0, 1 will be
returned instead.
siglongjmp() is similar to longjmp() except for the type of
its env argument. If the sigsetjmp() call that set this env
used a nonzero savesigs flag, siglongjmp() also restores the
set of blocked signals.
RETURN VALUE
These functions never return.
CONFORMING TO
POSIX
NOTES
POSIX does not specify whether longjmp will restore the sig-
nal context. If you want to save and restore signal masks,
use siglongjmp.
longjmp() and siglongjmp() make programs hard to understand
and maintain. If possible an alternative should be used.
SEE ALSO
setjmp(3), sigsetjmp(3)