NAME

       longjmp, siglongjmp - non-local jump to a saved stack context

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 signal 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)

                                                  March 2, 1997                                       LONGJMP(3)