Re: How hard is socket programming?

Peter Olcott wrote:


Any data that is not processed is RAW. :)

You got raw sockets and raw packets. In OCI Model, raw
packets can be defined to be at the data link level 2, raw
sockets at the IP networking level 3.

Example, PING utilities use raw sockets.


I don't get you. You have no choice but to use TCP based
sockets if you want to do HTTP, FTP, SMTP, NNTP, IMAP,
POP3, etc, programming.

Your "socket program" become "HTTP Program" only because
of the agreement between what data you will be sending and
the remote server will be receiving - the HTTP formatted
data.

Your "socket program" become "SMTP (EMAIL) Program" only
because of the agreement between what data you will be
sending and the remote server will be receiving - the SMTP
formatted data.

And so on and all cases, you have the same functions:

   socket() - pick up your telephone
   connect() - dial and answer
   send() - TALK ENGLISH
   recv() - HEAR ENGLISH
   close() - hang up

what makes it HTTP, is what you send and receive() over
the connection. No more.

The simple example is sending two lines as one string:

    CString s = ""
    s += "GET /HOMEPAGE.HTM HTTP 1.1\r\n";
    s += "HOST: peter.com\r\n";
    s += "\r\n";

    send(hsocket, s, strlen(s), 0);

Your web server, see the GET line, reads HOMEPAGE.HTM from
the server "root document" folder and dumps it out using
the send() command itself.

Now you read what the server sent, using recv() in some
loop:

    char buffer[1024*8];
    int len;
    while ((int len
=recv(hsocket,buffer,sizeof(buffer),0)> 0) {
       // I'm a web browser, display the html
       DisplayHTML(buffer, len);
    }

Thats it! Its all SOCKETS!

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HLS