A simple example of socket communication between two programs in Linux

Note:

These two programs should be run on the same machine. You need to create the/home/rangaofei/c_test/directory in advance.

This afternoon I learned about socket communication programming, read a book, and find an online explanation. Although it is still dizzy, the small experiment is still successful, and I plan to study it further tomorrow.

Two simple small programs, client. C and server. C, are compiled in the Ubuntu environment. One serves as the Socket Client and the other serves as the socket server. The GCC compilation is successful, and the communication is successful. Paste the code below:

/****************** Server program *****************/

# Include <stdio. h>
# Include <sys/types. h>
# Include <sys/socket. h>
# Include <string. h>
# Include <stdlib. h>
# Include <sys/UN. h>

Int main (){
Int sockfd, newfd, RET, recv_num, recv_num_total = 0;
Char Buf [50];
Struct sockaddr_un server_addr;
Remove ("/home/rangaofei/c_test/Server ");
Memset (& server_addr, 0, sizeof (server_addr ));
Server_addr.sun_family = af_unix;
Strcpy (server_addr.sun_path, "/home/rangaofei/c_test/Server ");
Sockfd = socket (af_unix, sock_stream, 0 );
If (sockfd <0 ){
Printf ("INVOKE socket function to build socket handle error! \ N ");
Exit (1 );
}
Printf ("build socket handle success ~ \ N ");
Ret = BIND (sockfd, (struct sockaddr *) (& server_addr), sizeof (server_addr ));
If (Ret <0 ){
Printf ("INVOKE bind func bind socket handle and address error! \ N ");
Exit (2 );
}
Printf ("bind socket handle and address specficed Success ~ \ N ");
Ret = listen (sockfd, 4 );
If (Ret <0 ){
Printf ("INVOKE listen function to make sure server can respond the request error! \ N ");
Exit (3 );
}
Printf ("respond the request Success ~ \ N ");
Newfd = accept (sockfd, null, null); // newfd connect client which call connect function
If (newfd <0 ){
Printf ("Call accept function error, build connection failed! \ N ");
Exit (4 );
}
Printf ("build connection with client success ~ \ N ");
While (1 ){
Recv_num = Recv (newfd, Buf, 24, 0 );
If (recv_num <0)
Printf ("Call Recv function receive message failed! \ N ");
Else {
Recv_num_total + = recv_num;
Printf ("Call Recv seccess ~, Received % d Words, message is \ "% s \". Total date received is % d. \ n ", recv_num, Buf, recv_num_total );
}
Sleep (1 );
}
}

/****************** Client program *****************/

# Include <stdio. h>
# Include <sys/types. h>
# Include <sys/socket. h>
# Include <string. h>
# Include <stdlib. h>
# Include <sys/UN. h>

Int main (){
Int sockfd, RET, send_num, send_num_total = 0;
Char Buf [50] = "this is my socket data .";
Struct sockaddr_un server_addr;
Memset (& server_addr, 0, sizeof (server_addr ));
Server_addr.sun_family = af_unix;
Strcpy (server_addr.sun_path, "/home/rangaofei/c_test/Server ");
Sockfd = socket (af_unix, sock_stream, 0 );
If (sockfd <0 ){
Printf ("INVOKE socket function to build socket handle error! \ N ");
Exit (1 );
}
Printf ("build socket handle success ~ \ N ");
Ret = connect (sockfd, (struct sockaddr *) (& server_addr), sizeof (server_addr ));
If (Ret <0 ){
Printf ("INVOKE connect func to connect server faild! \ N ");
Exit (2 );
}
Printf ("Connect server Success ~ \ N ");
While (1 ){
Send_num = Send (sockfd, Buf, sizeof (BUF), msg_dontwait );
If (send_num <0)
Printf ("call send function to send message to server failed! \ N ");
Else {
Send_num_total + = send_num;
Printf ("call send func seccess ~, Send % d Words, message is \ "% s \". Total date send is % d. \ n ", send_num, Buf, send_num_total );
}
Sleep (1 );
}
}

Note: When running these two programs, you must first run the server-side program; otherwise, an error will occur. The client cannot find the server. After the server is running, it will be blocked to wait for the client connection.

Reference: http://www.cnblogs.com/skynet/archive/2010/12/12/1903949.html