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)