Are there any recommended PHP libraries or functions for working with GUIDs in a C# program?

When working with GUIDs in a C# program, you may need to generate or manipulate GUIDs in PHP. One way to achieve this is by using the `com_create_guid()` function in PHP, which generates a globally unique identifier (GUID) in the same format as C#. This function can be called within a PHP script to generate GUIDs that can be used in a C# program.

// Generate a GUID using com_create_guid() function in PHP
function generateGUID() {
    if (function_exists('com_create_guid')) {
        return trim(com_create_guid(), '{}');
    } else {
        mt_srand((double)microtime()*10000);
        $charid = strtoupper(md5(uniqid(rand(), true)));
        $hyphen = chr(45); // "-"
        $uuid = chr(123) // "{"
            .substr($charid, 0, 8).$hyphen
            .substr($charid, 8, 4).$hyphen
            .substr($charid,12, 4).$hyphen
            .substr($charid,16, 4).$hyphen
            .substr($charid,20,12)
            .chr(125); // "}"
        return $uuid;
    }
}

// Example of generating a GUID
$guid = generateGUID();
echo $guid;