Re: [PATCH 2/2] t/README: hint about using $(pwd) rather than $PWD in tests

From: Jonathan Nieder <jrnieder@gmail.com>
Date: Jan 11, 2011, 08:37 UTC
Message-ID: <20110111083729.GD9445@burratino>
In-Reply-To: <4D2C11A5.4050709@viscovery.net>

Johannes Sixt wrote:

> Am 1/11/2011 8:54, schrieb Jonathan Nieder:

Show 9 quoted lines

>> Perhaps it is also worth explaining the cases where $PWD is needed?
>>
>> 	By contrast, when a passing a path to git or constructing a URL,
>> 	use $PWD.
>
> The first part of the "or" is not true: you can pass the result of $(pwd)
> to a command, and it means the same as $PWD; I would even recommend
> against $PWD so that a reader does not have to wonder "why pass $PWD, but
> check for $(pwd)?"

I _think_ that passing $PWD always gives the right result. By contrast, constructions like

	PATH=$(pwd)/bin:$PATH

break iirc.

I suspect that the reader will end up wondering "why does this have to be so complicated" no matter what.

> The second part I don't know whether it is true: I haven't noticed a
> pattern where people did it the wrong way, therefore, I'don't even know
> whether $PWD is really *always* required. Do *you* know?

24f1136 is one example.  I don't know of any utility that treats

	file://c:/foo/bar/baz

as a URL representing a resource on localhost (and msys bash has no rewriting rule for it), so in that particular case (file://$directory), $PWD really does seem to be always required.

Show 7 quoted lines

>>       It makes a difference on Windows, where
>>
>> 	 - $(pwd) is a Windows-style path such as git might output, and
>> 	 - $PWD is a Unix-style path that the shell (MSYS bash) will
>> 	   mangle before passing to native apps like git.
>
> This information is already included by reference to 4114156ae9.

... but if we can summarize it nicely, we can save the reader a step, no?

Anyway, what you have already written is useful; clearing up these details would just be icing on the top.