Path: utzoo!attcan!uunet!clyde.concordia.ca!news-server.csri.toronto.edu!utgpu!watserv1!ria!uwovax!7103_2622
From: 7103_2622@uwovax.uwo.ca (Eric Smith)
Newsgroups: comp.sys.atari.st.tech
Subject: Re: The program's name and path - how can I get them?
Message-ID: <7319.27104c1c@uwovax.uwo.ca>
Date: 8 Oct 90 13:51:23 GMT
References: <1990Oct8.110346@heike.informatik.uni-dortmund.de>
Lines: 36

> Does someone have a general solution? It would be sufficient to get only
> the directory where the program is located - without knowing the program's
> name. Even better would be a possibility to retrieve the program's name
> also, and the best would be if this could be done without GEM functions.
> And yes, of course only legal solutions are useful.
> 

I don't think there is a legal solution that always works (and the illegal
ones involving looking for variables in the parent's basepage certainly
break under multitasking systems, and probably on the TT as well).
However, a combination of legal solutions may work most of the time:

What I usually do is look at argv[0] in main(); gcc, MWC, and many other
compilers will fill this in with the program name if run from a shell that
supports the Atari ARGV= extended argument passing scheme. Note: some
shells will put only the program name (e.g. "arcgsh") in argv[0]; if so,
then you'll have to search the directories given in the PATH variable
to find the complete program.

If argv[0] is invalid (see below), then the best bet may be to look for
a PATH environment variable and search along it for your configuration file,
and/or use shel_find or shel_read. Almost all shells will set PATH, so if
no PATH is found and an invalid argv[0] is present then the program was
probably run from the desktop, and so the shel_* functions ought to work.

The ANSI standard says that argv[0] should be an empty string if the program
name is not available; the new gcc library does this. The old (1.27) gcc
library used to put "a.prg" in argv[0] by default, and some compilers may
put "a.out" there.

--
Eric R. Smith                     email:
Dept. of Mathematics            ersmith@uwovax.uwo.ca
University of Western Ontario   ersmith@uwovax.bitnet
London, Ont. Canada N6A 5B7
ph: (519) 661-3638