function Path::getLongestCommonBasePath

Returns the longest common base path in canonical form of a set of paths or `null` if the paths are on different Windows partitions.

Dot segments ("." and "..") are removed/collapsed and all slashes turned into forward slashes.

```php $basePath = Path::getLongestCommonBasePath( '/symfony/css/style.css', '/symfony/css/..' ); // => /symfony ```

The root is returned if no common base path can be found:

```php $basePath = Path::getLongestCommonBasePath( '/symfony/css/style.css', '/puli/css/..' ); // => / ```

If the paths are located on different Windows partitions, `null` is returned.

```php $basePath = Path::getLongestCommonBasePath( 'C:/symfony/css/style.css', 'D:/symfony/css/..' ); // => null ```

File

vendor/symfony/filesystem/Path.php, line 613

Class

Path

Contains utility methods for handling path strings.

Namespace

Symfony\Component\Filesystem

Code

public static function getLongestCommonBasePath(string ...$paths) : ?string {
    [
        $bpRoot,
        $basePath,
    ] = self::split(self::canonicalize(reset($paths)));
    for (next($paths); null !== key($paths) && '' !== $basePath; next($paths)) {
        [
            $root,
            $path,
        ] = self::split(self::canonicalize(current($paths)));
        // If we deal with different roots (e.g. C:/ vs. D:/), it's time
        // to quit
        if ($root !== $bpRoot) {
            return null;
        }
        // Make the base path shorter until it fits into path
        while (true) {
            if ('.' === $basePath) {
                // No more base paths
                $basePath = '';
                // next path
                continue 2;
            }
            // Prevent false positives for common prefixes
            // see isBasePath()
            if (str_starts_with($path . '/', $basePath . '/')) {
                // next path
                continue 2;
            }
            $basePath = \dirname($basePath);
        }
    }
    return $bpRoot . $basePath;
}