Let starts digging the code. At first we will discuss the echo client program. First, we check the number of argument passed.
Our simple example is an echo server that performs the following steps: The client reads a line of text from its standard input and writes the line to the server.
The server reads the line from its network input and echoes the line back to the client. The client reads the echoed line and prints it on its standard output. Despite two arrows between the client and server in the above figure, it is really a full-duplex TCP connection.
To expand this example into your own application, all you need to do is change what the server does with the input it receives from its clients. What happens when the client and server are started? What happens when the client terminates normally? What happens to the client if the server process terminates before the client is done?
What happens to the client if the server host crashes? In all these examples, we have "hard-coded" protocol-specific constants such as addresses and ports.
There are two reasons for this: We must understand exactly what needs to be stored in the protocol-specific address structures We have not yet covered the library functions that can make this more portable TCP Echo Server: The below code is the concurrent server program: Create socket, bind server's well-known port A TCP socket is created.
Binding the wildcard address tells the system that we will accept a connection destined for any local interface, in case the system is multihomed.
Our choice of the TCP port number is based on Figure 2. It should be greater than we do not need a reserved portgreater than to avoid conflict with the ephemeral ports allocated by many Berkeley-derived implementationsless than to avoid conflict with the "correct" range of ephemeral portsand it should not conflict with any registered port.
Wait for client connection to complete The server blocks in the call to accept, waiting for a client connection to complete. Concurrent server For each client, fork spawns a child, and the child handles the new client.
The child closes the listening socket and the parent closes the connected socket. It reads data from the client and echoes it back to the client.
Read a buffer and echo the buffer read reads data from the socket and the line is echoed back to the client by writen. If the client closes the connection the normal scenariothe receipt of the client's FIN causes the child's read to return 0.Writing a C-based Client/Server The next piece of information you need is the port number.
The port is an agreed upon connection point between the client and server. Sockets can be configured to act as a server and listen for incoming messages, or connect to other applications as a client. After both ends of a TCP/IP socket are connected, communication is bi-directional.
This sample program, based on the one in the standard library documentation, receives.
Chapter 5. TCP Client/Server Example¶ Introduction¶ We will now use the elementary functions from the previous chapter to write a complete TCP client/server example.
Our simple example is an echo server that performs the following steps: TCP Echo Server: main Function. Here we will create a simple echo client and echo server program where client send the message string to the server and server echoed back the same message string to the client.
Download the both client and server source code compile it and run both in command window. The echo server is a simple program that echoes input that is sent to the program through the network.
This application provides a good starting point for investigating how to write . PS and PL-Based Ethernet Performance with LightWeight IP Stack Authors: Bhargav Shah, Naveen Kumar Gaddipati, Akhilesh Mahajan, and • TCP/UDP TX throughput test Echo Server or write.
A RAW API-based echo server is single-threaded and all the work is done in the.