How to read multiple lines from socket stream? - php

Question

I want to retrieve email from gmails' imap server but the problem is that the responses from the server are multiple lines long (as demonstrated here) and fgets only retrieves one line.
I've tried using fgets, fread, socket_read but none of them work so either i'm using the wrong method or using the methods incorrectly. I also tried this tutorial but it didn't work either. I would appreciate if someone could help me with this.
Thanks and i'm really sorry if this is an amateur question.
Code:
<?php
$stuff = fsockopen('ssl://imap.gmail.com',993);
$reply = fgets($stuff,4096);
echo 'connection: '.$reply.'<br/>';
$request = fputs($stuff,"a1 LOGIN MyUserName Password\r\n");
$receive = socket_read($stuff, 4096);
echo 'login: '.$receive.'<br/>';
$request = fputs($stuff,"a2 EXAMINE INBOX\r\n");
$reply = '';
while(!feof($stuff))
$reply .= fread($stuff, 4096);
echo $reply;
/*
$request = fputs($stuff,'a3 FETCH 1 BODY[]\r\n');
$reply = fgets($stuff);
echo $reply;
*/
?>
Max's answer below works. This is my implementation of it.
private function Response($instructionNumber)
{
$end_of_response = false;
while (!$end_of_response)
{
$line = fgets($this->connection,self::responseSize);
$response .= $line.'<br/>';
if(preg_match("/$instructionNumber (OK|NO|BAD)/", $response,$responseCode))
$end_of_response = true;
}
return array('code' => $responseCode[1],
'response'=>$response);
}

Answer 1

Generally, you know to stop reading when you get the OK/BAD/NO response for the tag you sent. If you send a1 LOGIN ... you stop when you get a1 OK/BAD/NO ....

Answer 2

It's been a while since I wrote PHP, and I don't know that much about IMAP, but if it's anything like NNTP, your code would look a bit like this (wrote it in the SO editor, might be bugged) :
$buffer = '';
function read_line($socket) {
global $buffer;
while (strpos($buffer, "\n") === false)
$buffer .= fread($socket, 1024);
$lineEnd = strpos($buffer, "\n");
$line = substr($buffer, 0, $lineEnd-1);
$buffer = substr($buffer, $lineEnd);
return $line;
}
function send_line($socket, $line) {
fwrite($socket, $line);
}
$socket = fsockopen('ssl://imap.gmail.com',993);
$welcome = read_line($socket);
send_line("a1 LOGIN MyUserName Password\r\n");
$reply = read_line($socket);
send_line("a2 EXAMINE INBOX\r\n");
while (($reply = trim(read_line($socket))) != '.') {
echo $reply.PHP_EOL;
}
echo "Done";
The basic concepts are :
Always buffer all incoming data. PHP doesn't handle lines very well, so do the splitting yourself.
Don't randomly read everything, but know what to expect. You expect one welcome line, LOGIN has one reply, and EXAMINE INBOX keeps outputting data until there's a single dot, so immediately stop reading once you see that.
You'll most likely want a simple function to take care of the reading. You could even write another function to make it easy:
function read_block($socket) {
$block = '';
while ('.' != trim($reply = read_line($socket)) {
$block .= $reply;
}
return $block;
}