Re: Interfacing with telnet using curl

[HM 2K <nfhm2k@xxxxxxxxx>]

Before I report this as a bug, can anyone provide an example of how to
interface with a telnet server using curl?

Here's what I've tried, with various results:

<pre>
<?php

error_reporting(E_ALL);
ini_set('display_errors','On');

function curl_telnet($query,$server,$proxy=false,$timeout=10) {
  if (!function_exists('curl_init')) {
      user_error('"curl_init()" function does not exist.', E_USER_WARNING);
      return false;
  }
    $ch = curl_init($server);
  if ($proxy) {
    curl_setopt($ch, CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5);
    curl_setopt($ch, CURLOPT_PROXY, $proxy);
  }
    curl_setopt($ch, CURLOPT_TIMEOUT, $timeout);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
  curl_setopt($ch, CURLOPT_CUSTOMREQUEST, $query);
    $output=curl_exec($ch);
    curl_close($ch);
    return $output;
}

$tests=array();
$tests['rainmaker.wunderground.com:23']="\r\n\r\nx\r\n";
$tests['telnet://rainmaker.wunderground.com:23']="\r\n\r\nx\r\n";
$tests['towel.blinkenlights.nl:666']='';
$tests['telnet://towel.blinkenlights.nl:666']='';
$tests['whois.iana.org:43']="com\r\n";
$tests['telnet://whois.iana.org:43']="com\r\n";

foreach ($tests as $server => $query) {
  $result=curl_telnet($query,$server)?'good':'fail';
  echo "$server=$result\n";
}

?>

This results as following:

rainmaker.wunderground.com:23=good
telnet://rainmaker.wunderground.com:23=fail
towel.blinkenlights.nl:666=good
telnet://towel.blinkenlights.nl:666=good
whois.iana.org:43=good
telnet://whois.iana.org:43=fail

The obvious issue is that when you're not using the telnet:// protocol the
HTTP request is always sent. However, in some cases, when a query is sent,
using telnet:// will fail.

Is this a bug or is anyone else able to get telnet with curl to work as
expected?

Thanks.