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'

Orndorff

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' – Sabah

Answer 1

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));
}

Taboo

I went with this example since I wanted to check if it was a Symlink first as not all environments use them. – Orndorff

Thanks for the comment @Erwinus, will be good for people to know! Unfortunately I don't have a Windows 7 machine to test this! – Taboo

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. – Glaswegian

Answer 2

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

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

Chas

This doesn't seem to work for me - it doesn't return any output. – Orndorff

lorga - Weird, i'll have a play. I'm wondering it it's something with vhosts and how it's handling symlinks. Thanks! – Orndorff

No matter what I pass to it, it returns Warning: readlink(): Invalid argument :( – Orndorff

what are you trying to pass ? – Chas

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' – Orndorff

Answer 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

Qualitative

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 – Sabah

Answer 4

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

I wrote a package to do this: https://github.com/logical-and/symlink-detective

It allows you to do this:

<?php 

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

will return '/two/directory'

Augsburg

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 – Sabah

Answer 5

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

Edit : readlink seems to be a better answer :)

Kissiah