新聞財經娛樂♬資訊 News Economy

Just want to clarify my concept to some terminology on reading articles.As I know socket is connection and communication between client and server-side that we learnt it before on classical C . On php, there is also socket example such as on the socket tutorial link at http://php.net/manual/en/sockets.examples.php

Question-1, all php apache server TCP/IP are implemented by using exact socket function described on the previous link , and the  TCP/IP are including http,stmp, ftp,.....telent ..etc.Is it correct ?

Question-2 Websocket is another type of socket that is different from the socket function above, right? It aims to serve for web application such as chat/Game application since needs to bulid persistant connection. Is it correct ? The persisant connection means forever-active connection
that is NOT the same socket connection which is one-time process (create->connect->disconnect->done getting http pages). Is it right  ?

Question-3 I found one apache websocket at https://github.com/disconnect/apache-websocket.
People created that apache websocket code because classical  php apache doesn't have websocket function idea before so that it aims to create it  for the web application(Game and chat app) for old version php apache server. (Probably If the answer to question-2 above is correct, it imply this question-3 answer is also correct)

Please advise

Rwniceing

Yep, that's pretty much it.  Sockets are at a very low level and require a lot of work to use them.

Answer 1.  PHP sockets don't necessarily have anything to do with Apache.  The sockets themselves are part of the networking software in the operating system.  While basic protocols like HTTP and SMTP are not too hard, FTP gets more difficult because it requires a pair of sockets on different ports and it has a lot of overhead.  Protocols like HTTPS and SSH are probably pretty difficult to use because of the overhead for encrypting and decrypting the data.  Programs that use those protocols are usually written in C and compiled so they have less overhead than an interpreted language like PHP.

Answer 2+3.  'Websocket' is a specific application of sockets.  In the Apache article, it refers to WebSocket protocol (RFC 6455).  Like I said above, sockets are part of the networking software in the operating system.  http://en.wikipedia.org/wiki/WebSocket