php mcrypt_decrypt，base64_decode和换行符

Question

如何换行？例如：
一号线
2号线
3号线
解码后，看起来像 - ＆gt; line1 line2 line3

$key =  $_POST['key']; $input = $_POST['text'];

$algo = MCRYPT_RIJNDAEL_256;
$mode = MCRYPT_MODE_CBC;

$iv_size = mcrypt_get_iv_size($algo, $mode);
$iv = mcrypt_create_iv($iv_size, MCRYPT_DEV_URANDOM);

switch($_POST['do']){
    default: die;

    case 'encode':
    $ciphertext = mcrypt_encrypt($algo, $key, $input, $mode, $iv);
    $ciphertext = $iv . $ciphertext;
    echo base64_encode($ciphertext);
    break;

    case 'decode':
    $ciphertext_dec = base64_decode($input);
    $iv_dec = substr($ciphertext_dec, 0, $iv_size);
    $ciphertext_dec = substr($ciphertext_dec, $iv_size);
    echo htmlspecialchars(mcrypt_decrypt($algo, $key, $ciphertext_dec, $mode, $iv_dec));
    break;
}

Answer 1

解决。我用nl2br

echo nl2br(htmlspecialchars(mcrypt_decrypt($algo, $key, $ciphertext_dec, $mode, $iv_dec)));