Re: Mercurial 0.4b vs git patchbomb benchmark

From: Linus Torvalds <torvalds@osdl.org>
Date: May 2, 2005, 16:31 UTC
Message-ID: <Pine.LNX.4.58.0505020921080.3594@ppc970.osdl.org>
In-Reply-To: <42764C0C.8030604@tmr.com>

On Mon, 2 May 2005, Bill Davidsen wrote:

> > -#!/usr/bin/python
> > +#!/usr/bin/env python

> Could you explain why this is necessary or desirable? I looked at what 
> env does, and I am missing the point of duplicating bash normal 
> behaviour regarding definition of per-process environment entries.

It's not about environment.

It's about the fact that many people have things like python in /usr/local/bin/python, because they compiled it themselves or similar.

Pretty much the only path you can _really_ depend on for #! stuff is /bin/sh.

Any system that doesn't have /bin/sh is so fucked up that it's not worth worrying about. Anything else can be in /bin, /usr/bin or /usr/local/bin (and sometimes other strange places).

That said, I think the /usr/bin/env trick is stupid too. It may be more portable for various Linux distributions, but if you want _true_ portability, you use /bin/sh, and you do something like

	#!/bin/sh
	exec perl perlscript.pl "$@"

instead.
		Linus