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Message-ID: <b204959d-8d5b-6094-2ca1-65398cee4e20@gmail.com>
Date: Sun, 2 Apr 2017 19:28:48 +0100
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Subject: Re: [PHP-DEV] Directory separators on Windows
From: rowan.collins@gmail.com (Rowan Collins)

On 02/04/2017 09:09, Fleshgrinder wrote:
> Your strategy works in these examples, but the example I gave was
> different. Imagine that we have `/a/b/../c` which we would normalize to
> `/a/c`. However, the `b` component is actually a symbolic link to `x/y`.
> Hence, the real version of the path is `/a/x/c` and not `/a/c` as we
> would have normalized it to.

Both strategies are equally valid, as long as you know which is in use. 
There are many common tools outside PHP which use both approaches, and 
situations where you might actually want the string-based approach, even 
if filesystem access is available.

See for instance this discussion of pwd: 
http://unix.stackexchange.com/q/331208/70530 In summary, POSIX specifies 
"-L" (logical) which uses $PWD as set by the shell as you navigate, and 
"-P" (physical) which resolves backwards through the ".." links in the 
file system.

The same is true for other operations - for instance, the below demo in 
bash shows one interpretation in "ls" and the other in "cd".


/tmp/demo$ ls -lR
.:
drwxr-xr-x 2 vagrant vagrant 4096 Apr  2 18:21 foo
drwxr-xr-x 3 vagrant vagrant 4096 Apr  2 18:05 other

./foo:
lrwxrwxrwx 1 vagrant vagrant 21 Apr  2 18:21 bar -> /tmp/demo/other/thing

./other:
drwxr-xr-x 2 vagrant vagrant 4096 Apr  2 18:06 thing

/tmp/demo$ ls foo/bar/..
thing

/tmp/demo$ cd foo/bar/..
/tmp/demo/foo$ ls
bar

Regards,

-- 
Rowan Collins
[IMSoP]