note 15848 deleted from function.fsockopen by jimw

<p>For people trying FTP, and other line orientated protocols, remember:</p> <p>a) The server sends back information, too, and it's worth waiting for this response, because the command will have been fully processed by that point. (Hence the need for sleep(1) above - this isn't needed if you read the server's response.) You'll also get the error messages and codes - these are useful user feedback. Besides all these good reasons, you'll be using less memory, because you'll be clearing the socket read buffer.<br> b) Most line orientated protocols have some form of "quit" or "logout" command. It's best to use these. More generally, it's best to let the server close the socket when it's good and ready - some protocols "do" things on the quit command, which can otherwise cause immediate reconnections to fail. (Some POP3 servers do this, for instance. And are quite within their rights to do so.)<br> c) A few of these protocols can support "pipelining" - sending a bunch of commands at once. ESMTP is one of these - it'll tell you after the "EHLO" command. Although some protocols generally manage to support it on some servers, even if they don't tell you (and sometimes don't have the means to tell you), it's best not to rely on this. FTP, for instance, often will manage the USER/PASS sequence all at once, but there's nothing in the standard to insist on it.<br> d)Also, read the standards documents (RFCs) on the protocols you're trying to speak. It's actually much easier than trying to reverse engineer them, although you might find it useful to look at someone else's implementation for reference as well.<br> e)If you're trying to do TELNET, or any TELNET based protocol (Such as FTP), then please remember that TELNET is not a line orientated protocol. FTP clients can, if I remember right, get away without handling TELNET, except for certain filenames - FTP supports 8-bit filenames these days, and you'll need to double up the octet FF (also known as IAC) whereever it appears.</p> <p>My apologies for berating the obvious.</p>