NAME

       setjmp, sigsetjmp - save stack context for non-local goto

SYNOPSIS

       #include <setjmp.h>

       int setjmp(jmp_buf env);
       int sigsetjmp(sigjmp_buf env, int savesigs);

DESCRIPTION

       setjmp()  and  longjmp()  are  useful  for  dealing with errors and interrupts encountered in a low-level
       subroutine of a program.  setjmp() saves the stack context/environment in env for later use by longjmp().
       The stack context will be invalidated if the function which called setjmp() returns.

       sigsetjmp() is similar to setjmp().  If savesigs is nonzero, the set of blocked signals is saved  in  env
       and will be restored if a siglongjmp() is later performed with this env.

RETURN VALUE

       setjmp() and sigsetjmp() return 0 if returning directly, and non-zero when returning from longjmp() using
       the saved context.

CONFORMING TO

       POSIX, ISO 9899

NOTES

       POSIX  does  not  specify whether setjmp will save the signal context. (In SYSV it will not. In BSD4.3 it
       will, and there is a function _setjmp that will not.)  If you want to save signal masks, use sigsetjmp.

       setjmp() and sigsetjmp make programs hard to understand and maintain.  If possible an alternative  should
       be used.

SEE ALSO

       longjmp(3), siglongjmp(3)

                                                  March 2, 1997                                        SETJMP(3)