dirname() produces invalid root path

[mabar]

Description

The following code:

<?php
echo dirname('file://file.txt');

Resulted in this output:

file:

But I expected this output instead:

file://

https://3v4l.org/6FlUN

While it may not be problem with real filesystem where writing to root directory is a no-go, it's quite useful in tests for writing via custom stream wrapper into a php variable which exists just for that test. Following code used to create directories hierarchy before writing into file due to the problem creates directory vfs.var: in current working directory instead of (not) creating root directory.

$file = 'vfs.var://file.txt';
$dir = dirname($file);
if (!@mkdir($dir, $mode, true) && !is_dir($dir)) {
	// exception
}
file_put_contents($file, '');

PHP Version

All

Operating System

No response

[bwoebi]

This is not a bug. dirname() is explicitely for paths, not uniform resource locators or identifiers.

A double slash in a path is simply simplified to a single slash. And, under Linux at least, a colon is a valid part of a path (though it is used as a path separator in some contexts, you can have a directory named file:).

PHP has no direct facilities for URI parsing (URL parsing is provided by parse_url()).