public static function get_file_version( $file ) {

		// Avoid notices if file does not exist.
		if ( ! file_exists( $file ) ) {
			return '';
		}

		// We don't need to write to the file, so just open for reading.
		$fp = fopen( $file, 'r' ); // @codingStandardsIgnoreLine.

		// Pull only the first 8kiB of the file in.
		$file_data = fread( $fp, 8192 ); // @codingStandardsIgnoreLine.

		// PHP will close file handle, but we are good citizens.
		fclose( $fp ); // @codingStandardsIgnoreLine.

		// Make sure we catch CR-only line endings.
		$file_data = str_replace( "\r", "\n", $file_data );
		$version   = '';

		if ( preg_match( '/^[ \t\/*#@]*' . preg_quote( '@version', '/' ) . '(.*)$/mi', $file_data, $match ) && $match[1] ) {
			$version = _cleanup_header_comment( $match[1] );
		}

		return $version;
	}