StackOverflow: PHP read data from several text files, output

<?php
    //Answer to: http://stackoverflow.com/questions/7180128/php-read-data-from-several-text-files-outputting-a-certain-line-from-all-files/

    function readAfterColon($string) {
        /**
         * @param string $string The string you'd like to split on.
         *
         * @return string The data after the colon.  Multiple colons work just fine.
         */
        $array = explode(":",$string, 2);
        return isset($array[1]) ? $array[1] : '';
    }

    function readLine($lineNumber, $fileName) {
        /**
         * @param int $lineNumber The line number you want to read from the file.
         * @param string $fileName The string representing the file you wish to open.
         *
         * @return string The contents of the line in the file.
         */
        $file = file($fileName);
        return $file[$lineNumber-1];
    }

    function readLineFrom($lineNumber, $fileNames) {
        /**
         * @param int $lineNumber The line number you want to read from the file.
         * @param string|array $files Either a string for the file you want to open, or an array of filenames.
         *
         * @return array An associative array of the filename to the contents of the line.
         */
        $lines = array();
        if(is_array($fileNames)) {
            foreach($fileNames as $fileName) {
                $lines[$fileName] = readLine($lineNumber, $fileName);
            }
        } else {
            $lines[$fileNames] = readLine($lineNumber, $fileNames);
        }

        return $lines;
    }

    function getFileNamesFromDirectory($directory = '.') {
        /**
         * @param string $directory The path to directory you'd like to get filenames from. Defaults to current directory.
         *
         * @return array An array of filenames.  Empty if there are no files.
         */
        $fileNames = array();
        if ($handle = opendir($directory)) {
            while (false !== ($file = readdir($handle))) {
                if ($file != "." && $file != "..") {
                    $fileNames[] = $directory . $file;
                }
            }
            closedir($handle);
        }
        return $fileNames;
    }


    //get the line from every file
    $descriptions = readLineFrom(5, getFileNamesFromDirectory('/var/www/test/'));

    //get the contents after the colon
    foreach($descriptions as $fileName=>$description) {
        $descriptions[$fileName] = readAfterColon($description);
    }

    //display it
    echo "<pre>\n";
    print_r($descriptions);
    echo "</pre>";
?>