PHP - Get relative path from one directory to another

Solution:

The Amir MB's solution seems flawed in a few ways.

Say we have repetitions in folder names throughout the path.

/var/www/src/vendor/package/public
/var/www/vendor/src/index.php
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Your solution returns:

../../src/index.php/
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i.e., where it stumbles upon a repetitive (existing in both paths) folder name, the ascension breaks off.

The correct answer must be:

../../../../vendor/src/index.php
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And in

/var/www/src/vendor_1/Package_1/public
/var/www/vendor/src/index.php

Flawed: ../../../index.php/
Correct: ../../../../vendor/src/index.php
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When both paths are relative, a similar thing occurs:

src/vendor_1/Package_1/public
vendor/src/index.php

Flawed: ../../../index.php/
Correct: ../../../../vendor/src/index.php
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I came across other cases where the solution failed. The algorithm has to be changed.

Here is a simple function given the source and destination EXIST:

function getRelativePath($source, $destination)
{
    $paths =
        array_map(fn ($arg) => explode('/', realpath($arg)), func_get_args());
    return
        str_repeat('../', count(array_diff_assoc(...$paths))) .
        implode('/', array_diff_assoc(...array_reverse($paths)));
}
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Nothing fancy. No check is implemented on the source being a folder and not a file (note the destination can be a file while the source is supposed to be a directory from where the relative path is calculated.

I will probably come back shortly with a universal solution for any path, existing or not, as relative as absolute.