Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!utah-gr!uplherc!sp7040!obie!wes
From: wes@obie.UUCP (Barnacle Wes)
Newsgroups: comp.sys.atari.st
Subject: Re: Fsfirst/Fsnext question
Summary: Sure, just save/restore the DTA
Message-ID: <174@obie.UUCP>
Date: 28 Aug 88 04:54:08 GMT
References: <566@laura.UUCP>
Organization: the Well of Souls
Lines: 44

In article <566@laura.UUCP>, klute%trillian.irb@unido.uucp
(Rainer Klute) writes:

> does anyone know about a 'legal' way to do something like this:

Sure, make your code look like:

Routine_A:			Routine_B:
==========			==========
DTA *save, my_dta;
save = Fgetdta();
Fsetdta(my_dta);
 .
Fsfirst (...);
Fsnext ();
 .
Call_Routine_B ();
 .				DTA *save, local_dta; 
 .				save = Fgetdta();
 .				Fsetdta(local_dta);
 .				 .
 .				Fsfirst (...);
 .				Fsnext ();
 .				 .
 .				Fsetdta(save);
 .				return;
 .
Fsnext();
Fsetdta(save);
return;

In general, it is a good idea to always work with your own DTA.  You can
even use this to advantage in different routines, as long as you are
careful to restore the previous DTA before returning.

CAVEAT: I wrote this off the top of my head, without consulting ANY
manuals at all.  The intent is correct, but I am sure the code wouldn't
compile and run at all.  Look up the calling sequence for Fsetdta and
Fgetdta CAREFULLY before trying this.
-- 
                     {hpda, uwmcsd1}!sp7040!obie!wes
           "Happiness lies in being priviledged to work hard for
           long hours in doing whatever you think is worth doing."
                         -- Robert A. Heinlein --