v7 man page for setjmp

SETJMP(3)						     Library Functions Manual							 SETJMP(3)

NAME
       setjmp, longjmp - non-local goto

SYNOPSIS
       #include <setjmp.h>

       setjmp(env)
       jmp_buf env;

       longjmp(env, val)
       jmp_buf env;

DESCRIPTION
       These routines are useful for dealing with errors and interrupts encountered in a low-level subroutine of a program.

       Setjmp saves its stack environment in env for later use by longjmp.  It returns value 0.

       Longjmp	restores  the environment saved by the last call of setjmp.  It then returns in such a way that execution continues as if the call
       of setjmp had just returned the value val to the function that invoked setjmp, which must not itself have returned  in  the  interim.   All
       accessible data have values as of the time longjmp was called.

SEE ALSO
       signal(2)

																	 SETJMP(3)