Subject:	Re: m4 port: return program name as 'm4' not '/some/path/m4.exe'
	[PATCH]
From:	Tim Van Holder <tim DOT van DOT holder AT pandora DOT be>
To:	djgpp-workers AT delorie DOT com
In-Reply-To:	<3E1B35F9.DC4EA825@phekda.freeserve.co.uk>
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	<3E19BEAE DOT 7CC5B46C AT phekda DOT freeserve DOT co DOT uk>
	<200301061840 DOT h06IebI26175 AT envy DOT delorie DOT com>
	<3E1B35F9 DOT DC4EA825 AT phekda DOT freeserve DOT co DOT uk>
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Date:	08 Jan 2003 11:47:36 +0100
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On Tue, 2003-01-07 at 21:18, Richard Dawe wrote:
> Hello.
> 
> DJ Delorie wrote:
> > Note that for maximum unix compatibility, we should probably do this:
> > 
> > In the crt0 code, compare the path to our executable to the $PATH.  If
> > we were found in some directory already on the $PATH, omit the
> > directory and leave the basename.  If we were not found on the $PATH,
> > leave the full path alone.
> 
> With or without the '.exe'?
>  
> > Another thing we might consider is to remove the drive specifier if it
> > happens to be the current drive.  For many cases, this will make it
> > look unix-like enough to work with dos-unaware programs.
> 
> Why not just munge it from say c:/ to /dev/c/? That makes it Unixy enough and
> doesn't involve information loss.
> 
> I suppose there could be two styles of munging:
> 
> * just return the stem without extension - Unix-style;

Yes and no; on Unix, argv0 is exactly what was typed (e.g. if you run
/bin/rm, argv0 is '/bin/rm', not 'rm').  Many, but not all, GNU tools
use basename(argv0) for --version for exactly this reason.
Canonicalizing argv0 seems like a better idea then; programs can always
use basename() or some such to strip the path.  Might be nice to expand
LFNs in it as well; currently argv0 is always SFN even on LFN platforms
(or so I seem to recall).

Not sure what our bash does now; if it uses exec*(), it can pass image
name and argv0 separately to provide exact Unix-like behaviour.  Maybe
system() could be changed accordingly as well, leaving only invocations
from command.com to get the 'full' path as argv0.

> * return a path converted to /dev-style - Unix-friendly.
> 
> Should either of these argv[0] mungings be on by default?

I'd say yes, possibly with a crt0 flag to disable it.

-- 
Tim Van Holder <tim DOT van DOT holder AT pandora DOT be>

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