<?

Class FTP {
	var $port;
	var $host;
	
	var $sock;
	var $data_sock;
	
	var $errno;
	var $errstr;
	var $message;
	
	
	
	
	function FTP($host,$port=21)
	{
		$this->host = $host;
		$this->port = $port;
	}
	
	function connect()
	{
		
		$this->sock = fsockopen($this->host,$this->port,&$this->errno,&$this->errstr,30);
		set_socket_blocking($this->sock,false);
		return $this->sock;
	}

	/**
	 * will read data from the socket. Since we are using non blocking 
	 * mode, if we attempt to read the data even a millisecond before 
	 * it becomes available, the method just returns null.
	 *
	 * So what's the cure? we will loop for a while and try to read it
	 * in multiple times. Note that if we used blocking mode there may
	 * be instances when this function NEVER returns.
	 */
	function sock_read($i=0)
	{
		$s = fgets($this->sock);
		if($s=='')
		{
			if($i==30)
			{
				return "";
			}
			else
			{
				sleep(1);
				return $this->sock_read($i+1);
			}
		}
		return $s;
	}

	function is_ok()
	{
	
		$this->message = $this->sock_read();

		if($this->message == "" || preg_match('/^5/',$this->message) )
		{
			return 0;
		}
		else
		{
			return 1;
		}
	}

	function sock_write($s)
	{
		echo "< $s\n";
		fputs($this->sock,"$s\n");
	}

	function dir_list($path="")
	{
		$s="";
		if($this->pasv())
		{
			if($path == '')
			{
				$this->sock_write("LIST");
			}
			else
			{
				$this->sock_write("LIST $path");
			}
			if($this->is_ok())
			{
				while(true)
				{
					$line = fgets($this->data_sock);
					$s .= $line;
					if($line =='')
						break;
				}
			}
		}
		return $s;
	}
	
	function pasv()
	{
		$this->sock_write("PASV");
		if($this->is_ok())
		{
			$offset = strpos($this->message,"(");
			
			$s = substr($this->message,++$offset,strlen($this->messsage)-2);
			$parts = split(",",trim($s));
			$data_host = "$parts[0].$parts[1].$parts[2].$parts[3]";
			$data_port = ((int)$parts[4] << 8) + (int) $parts[5];
		
			$this->data_sock = fsockopen($data_host,$data_port,&$errno,&$errstr,30);
			return $this->data_sock;
		}
		return "";
	}
}

$ftp = new FTP("localhost");
$sock = $ftp->connect();

if($sock)
{
	if($ftp->is_ok()==1)
	{
		$ftp->sock_write("user imapuser");

		if($ftp->is_ok())
		{
			$ftp->sock_write("pass 123");
			if($ftp->is_ok())
			{
				echo $ftp->dir_list();
			}
		}
	}
}

?>