Get class name from file

get_class_name.php

<?php

/**
 * Get class name from file
 *
 * This is a working example, that works for PHP 7.4 and 8.x.
 *
 * @see https://stackoverflow.com/questions/7153000/get-class-name-from-file
 */
function get_class_name(string $file): string
{
    $tokens = token_get_all(file_get_contents($file));
    $tokensCount = count($tokens);

    $className = '';
    $namespaceName = '';

    for ($i = 0; $i < $tokensCount; $i++) {
        // namespace token
        if (is_array($tokens[$i]) && (token_name($tokens[$i][0]) === 'T_NAMESPACE')) {
            for ($j = $i + 1; $j < $tokensCount; $j++) {
                if ($tokens[$j][0] === ';') {
                    break;
                }
                $tokenName = token_name($tokens[$j][0]);
                if ($tokenName === 'T_WHITESPACE') {
                    continue;
                }
                if (in_array($tokenName, ['T_NAME_QUALIFIED', 'T_NS_SEPARATOR', 'T_STRING'])) {
                    $namespaceName .= $tokens[$j][1];
                }
            }
        }
        // class token
        if (is_array($tokens[$i]) && (token_name($tokens[$i][0]) === 'T_CLASS')) {
            for ($j = $i + 1; $j < count($tokens); $j++) {
                $tokenName = token_name($tokens[$j][0]);
                if ($tokenName === 'T_WHITESPACE') {
                    continue;
                }
                if ($tokenName === 'T_STRING') {
                    $className = $tokens[$j][1];
                    break;
                }
            }
        }
    }

    if (strlen($namespaceName) === 0) {
        return $className;
    }

    return $namespaceName . '\\' . $className;
}