PHP dirname returns symlink path

Question

Say I have a symlink from '/one/directory/' to '/two/directory/'.

If I echo dirname(dirname(\__FILE__)), it returns '/one/directory/'.

What is the best method to return '/two/directory'?

Example usage:

Vhost 'example.com' pointing to `'/two/directory'

example.com/hello_world.php
<?php 
    echo dirname(dirname(__FILE__));
?>

Returns: '/one/directory'

Expected results: '/two/directory'

Your question is not quite clear, what is the symlink and what is the real directory? According the documentation, symlinks are automatically resolved with __FILE__ from old php 4.0.2, so it would be reasonable to think, that you complain that you consider symlink being the 'two' directory and you complain the __FILE__ returning the original = symlink resolved directory 'one'. Though almost all the answer here reply as if the original directory was two, the symlink one, and the PHP did not behave as they write in documentation, that the __FILE__ var would return not symlinked resolved 'one' — FantomX1, Aug 07 '20 at 14:08

score 10 · Accepted Answer · answered Sep 25 '12 at 09:47

10

Use the readlink function? http://php.net/manual/en/function.readlink.php

You can check if it is a symlink with is_link: http://php.net/manual/en/function.is-link.php

if (is_link($link)) {
    echo(readlink($link));
}

answered Sep 25 '12 at 09:47

manavo

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I went with this example since I wanted to check if it was a Symlink first as not all environments use them. – adamstrawson Sep 26 '12 at 07:55
Thanks for the comment @Erwinus, will be good for people to know! Unfortunately I don't have a Windows 7 machine to test this! – manavo Jan 20 '16 at 10:44
Update: now works on Windows, along with link(), symlink() and linkinfo() - since PHP 5.3.0 according to the manual. I confirm it does work on Windows 7. – Bigue Nique Nov 18 '17 at 08:27

score 7 · Answer 2 · edited Sep 25 '12 at 09:51

7

Use readlink($path) to read the target of symbolic link.

<?php 
    echo readlink(dirname(__FILE__));
?>

edited Sep 25 '12 at 09:51

Starx

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answered Sep 25 '12 at 09:46

Mihai Iorga

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This doesn't seem to work for me - it doesn't return any output. – adamstrawson Sep 25 '12 at 10:02
lorga - Weird, i'll have a play. I'm wondering it it's something with vhosts and how it's handling symlinks. Thanks! – adamstrawson Sep 25 '12 at 10:07
2

No matter what I pass to it, it returns `Warning: readlink(): Invalid argument` :( – adamstrawson Sep 25 '12 at 10:21
what are you trying to pass ? – Mihai Iorga Sep 25 '12 at 10:24
I've worked it out, but it seems to be backwards. I have to pass `'/two/directory'` for it to work, when I want to pass `'/one/directory'` to get `'/two/directory'` – adamstrawson Sep 25 '12 at 10:27

score 3 · Answer 3 · answered Sep 25 '12 at 09:49

3

<?php

function getRealFile($path) {
    return is_link($path) ? readlink($path) : $path;
}

$path = getRealFile(dirname(__FILE__));

Documentation:

http://php.net/manual/en/function.is-link.php
http://php.net/manual/en/function.readlink.php

answered Sep 25 '12 at 09:49

Eugene Naydenov

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According to php docs version 4.0.2 above, __FILE__ is always automatically symlink resolved, so I don't know why you suggest a function for something, what is implicitly done, and the asker asks for the opposite. Analogy to how it sounds : ` function getZero(number) { return number==0 ? number * 0 : number; } ` and then posting a link to math forum mentioning that the result of multiplication by 0 is zero Your answer might be an answer, but not for this question, when the supplied parameter is __FILE__ as in your example – FantomX1 Aug 07 '20 at 14:20

score 2 · Answer 4 · answered Nov 05 '16 at 08:49

2

What is the best method to return '/two/directory'?

Use the https://github.com/logical-and/symlink-detective and

<?php 

echo SymlinkDetective::detectPath(dirname(dirname(__FILE__)));

will return '/two/directory'

answered Nov 05 '16 at 08:49

And

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5

Seems like he wants to get a symlink path = symlink unresolved path, and you are suggesting him the opposite in other words - what he already has, as there is no way in php not to get non symlink resolved path with __FILE__ according to docs – FantomX1 Aug 07 '20 at 14:18

score 1 · Answer 5 · answered Sep 25 '12 at 09:47

1

Maybe with realpath() ? http://php.net/manual/en/function.realpath.php

Edit : readlink seems to be a better answer :)

answered Sep 25 '12 at 09:47

Fry_95

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PHP dirname returns symlink path

5 Answers5

Linked