Unix Network Programming, Volume 1: The Sockets Networking API (3rd Edition)

5.3 TCP Echo Server: str_echo Function

The function str_echo , shown in Figure 5.3, performs the server processing for each client: It reads data from the client and echoes it back to the client.

Read a buffer and echo the buffer

8 “9 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 scenario), the receipt of the client's FIN causes the child's read to return 0. This causes the str_echo function to return, which terminates the child in Figure 5.2