It helps in manipulating options for the socket referred by the file descriptor. Really cool, it actually works unlike other tutorials. How do I make it so when the server restarts, the client is able to connect in the same session, without having to restart the client? Your email address will not be published. What is Socket? It will be processed here.
The system calls for establishing a connection are somewhat different for the client and the server, but both involve the basic construct of a socket. A socket is one end of an interprocess communication channel. The two processes each establish their own socket.
The steps involved in establishing a socket on the client side are as follows:. The steps involved in establishing a socket on the server side are as follows:. In numerous examples, what we see is how a single client is connected to a socket in a server. However, this is not the case in day to day life. We have multiple clients connected to a server and each has a different socket. One way to achieve this feat is by using multithreading.
But only someone who has done multithread programming knows it can lead to madness. They are very difficult to code and debug. Even if you end up programming them neatly, the results can be unpredictable. Not to mention the fact that they are not scalable for a large number of clients and there is also a chance of deadlocks occurring. To tackle these issues, we try to support multiple clients on a network without using multithreading.
To help us with this, we have a special function known as select. It gets activated as soon as any file descriptor sends data. Hence it works like an interrupt handler. If some data is there that is to be read on one of the sockets then it is select that provides that information.
There are four macros that are associated with the select function, used for manipulating and checking the descriptor sets. Using these four macros and the select function, one can handle multiple clients using a single thread. Here is an example server side code which echos back the received message. Jump here for the explanation of the code. When a new client connects to the server, master-sock will be activated and a new file descriptor will be open for that particular client.
Sockets; using System. GetHostEntry Dns. AddressFamily, SocketType. Stream, ProtocolType. Receive messageReceived ; Console. Shutdown SocketShutdown.
Both ; sender. WriteLine e. WriteLine "Waiting connection GetString bytes, 0, numByte ; if data. Both ; clientSocket. After that on another cmd execute the client code and see the following output on the server side cmd. Now you can see the changes on the server as soon as the client program executes. Skip to content.
Change Language. Before we start our tutorial, keep in mind that the following tutorial only works for Linux OS environment. If you are using Windows, I have to apologize to you because Windows has its own socket programming and it is different from Linux even though the connection concept is the same.
Well, first copy and paste the following code and run it on server and client, respectively. After debugging both source files, run Socket-server. Attention here, never mess up with the order of executing Socket-server.
Socket-server must be executed first, then execute Socket-client. It means, you need to open two terminals to run each of the outputs. If you see the message above, congratulations, you have success with your first step to networking programming.
Otherwise, do some checking on your development environment or try to run some simple code for instance hello world. The answer is the server and client both are software but not hardware. It means what is happening on the top is there are two different software executed.
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