Path: utzoo!attcan!uunet!samsung!sdd.hp.com!decwrl!ucbvax!mindcrf.UUCP!karish
From: karish@mindcrf.UUCP (Chuck Karish)
Newsgroups: comp.unix.questions
Subject: Re: Is there a way not to use global variables for signal,setjmp,lonjmp?
Summary: Huh?
Message-ID: <9009170633.AA23056@mindcrf.mindcraft.com>
Date: 17 Sep 90 06:33:02 GMT
References: <119@wookie.dbaccess.com>
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: Mindcraft, Inc.
Lines: 26

In article <119@wookie.dbaccess.com> ivan@dbaccess.com
(Ivan Covdy) writes:
>In:
>    signal( SignalValue, ActionFunction );
>the function ActionFunction can be defined only as:
>    void ActionFunction( int );   i.e., it can have only one argument.

>What should I do if I want to have such ActionFunction, which changes
>variables, and these variables should not be global/external/static?
>Are there any ways to pass more arguments to ActionFunction?

No.  The user process doesn't pass ANY arguments to the signal-catching
function.  The system passes the signal number.

>The same question is for setjmp(Env) and longjmp(Env, 0):
>    are there any ways to get rid of the global variable Env?

There's no requirement that `Env' be a global variable.  It's a
structure into which setjmp() saves the process state at the time
setjmp() is called.  A process is allowed to save any number of
non-global jmpbuf structures, and feed the structure of its choice to
longjmp() to jump to the desired state.
-- 

	Chuck Karish		karish@mindcraft.com
	Mindcraft, Inc.		(415) 323-9000