PHP Transform Linux subsystem path to windows path

Question

I have a PHP application running in the Linux subsystem for Windows.

The application talks to an external .exe file that requires a filename as an input.

In my PHP application, I need to determine if the file exists before trying to send it to the external .exe file.

To summarise, when in my PHP application I need the Linux file path, but when passing it as an argument to the .exe I need the windows file path.

So it would look something like this:

<?php

$fn = '/mnt/c/myapp/myfile.png';

$exists = file_exists($fn);

if ($exists) {
    shell_exec('external.exe -f ' . transformToWindowsPath($fn));
}

function transformToWindowsPath($fn)
{
    // What should go here?
    // Is something like this reliable?
    return str_replace(
        '/',
        DIRECTORY_SEPARATOR,
        preg_replace_callback(
            '/\/mnt\/([a-zA-Z])\//',
            function($matches) {
                return strtoupper($matches[1]) . ":" . DIRECTORY_SEPARATOR;
            },
            $fn
        )
    );
}

Answer 1

Try with this function that converts the directory separator:

$fn = '/mnt/c/myapp/myfile.png';

function fnSystem($fn, $system='linux')
{
    if($system == 'windows')
    {
        $fn = str_replace('/mnt/c/', '', $fn); // remove /mnt/c/ from front
        $fn = str_replace('/', '\\', $fn); // convert the directory separator
        $fn = "C://$fn"; // place C:// in front
    }
    elseif($system == 'linux')
    {
        $fn = str_replace('C://', '', $fn); // remove C:// from front
        $fn = str_replace('\\', '/', $fn); // convert the directory separator
        $fn = "/mnt/c/$fn"; // place /mnt/c/ in front
    }

    return $fn;
}

$fnWindows = fnSystem('/mnt/c/myapp/myfile.png', 'windows');

echo $fnWindows;

Result:

C://myapp\myfile.png