Socket communication under Linux (next)

Write your own client program

Also is to achieve the function of the previous article, the client program is no longer using Telnet, their own code implementation, the server-side program needs to be modified under

1. Server programs

#include <stdio.h>#include <stdlib.h>#include <unistd.h>#include <string.h>#include <errno.h>#include <sys/socket.h>#include <arpa/inet.h>voidErrorChar*MSG) {fprintf(stderr,"%s:%s\n", MSG, strerror (errno));Exit(1);}intOpen_listener_socket (void){ints = socket (pf_inet, Sock_stream,0);//Create server socket, IPV4 protocol, connection-oriented communication, TCP protocol    if(s = =-1) Error ("Scoket Open Error");returns;}voidBind_to_port (intSocketintPort) {structsockaddr_in name;//server network address structurename.sin_family = pf_inet; Name.sin_port = (in_port_t) htons (port);//server port numberNAME.SIN_ADDR.S_ADDR = htonl (Inaddr_any);//server address, allow connection to all local connections    //Set socket to re-use already bound interface    intReuse =1;if(socket, Sol_socket, SO_REUSEADDR, (setsockopt) (Char*) &reuse,sizeof(int)) == -1) Error ("Cant set the reuse option on the Scoket");//Bind the server socket to the network address    intc = bind (socket, (structsockaddr*) &name,sizeof(name));if(c = =-1) Error ("cant bind to socket");}intSent_msg_to_client (intSocketChar*s) {intresult = Send (socket, S,strlen(s),0);if(Result = =-1)fprintf(stderr,"%s:%s\n","Error talking to client", Strerror (errno));returnResult;}intMainintargcChar Const*argv[]) {intSERVER_SOCKFD;intLen    SERVER_SOCKFD = Open_listener_socket (); Bind_to_port (SERVER_SOCKFD,30000);//Listen for connection requests, listening queue Length is ten    if(Listen (SERVER_SOCKFD,Ten) == -1) Error ("Cant listen");structSockaddr_storage client_addr;//client_addr to save the connection client details    unsigned intAddress_size =sizeof(CLIENT_ADDR);puts("Waiting for Connection");Charbuf[255];//Wait for client connection request to arrive    intCLIENT_SOCKFD = Accept (SERVER_SOCKFD, (structSOCKADDR *) &client_addr, &address_size);if(CLIENT_SOCKFD = =-1) Error ("Accept Error"); Sent_msg_to_client (CLIENT_SOCKFD,"Welcome to my Server\n>"); while(len = recv (CLIENT_SOCKFD, buf,sizeof(BUF),0)) >0) {Buf[len] =' + ';printf("%s\n", buf);if(STRNCASECMP ("Who is there?", BUF, A)) Sent_msg_to_client (CLIENT_SOCKFD,"You should say ' Who's is there? '!\r\n>");Else{Sent_msg_to_client (CLIENT_SOCKFD,"Oscar\r\n>"); while(len = recv (CLIENT_SOCKFD, buf,sizeof(BUF),0)) >0) {Buf[len] =' + ';printf("%s\n", buf);if(STRNCASECMP ("Oscar who?", BUF,9) {sent_msg_to_client (CLIENT_SOCKFD,"You should say ' Oscar The Who? '!\r\n> ');Continue; }Else{Sent_msg_to_client (CLIENT_SOCKFD,"Oscar silly question, you get a silly answer\r\n"); Break; }            }        }    }return 0;}

1. Client programs

#include <stdio.h>#include <stdlib.h>#include <unistd.h>#include <string.h>#include <errno.h>#include <sys/socket.h>#include <arpa/inet.h>voidErrorChar*MSG) {fprintf(stderr,"%s:%s\n", MSG, strerror (errno));Exit(1);}intOpen_listener_socket (void){ints = socket (af_inet, Sock_stream,0);//Create server socket, IPV4 protocol, connection-oriented communication, TCP protocol    if(s = =-1) Error ("Scoket Open Error");returns;}intMainintargcChar*argv[]) {intCLIENT_SOCKFD;Charbuf[255];intLenstructSockaddr_in client_addr;//Client network address structureClient_addr.sin_family=pf_inet;//Set as IP communicationCLIENT_ADDR.SIN_ADDR.S_ADDR=INET_ADDR ("127.0.0.1");//server IP addressClient_addr.sin_port=htons (30000);//server port number    / * Create a client socket--IPV4 protocol, connection-oriented communication, TCP protocol * /Client_sockfd= Open_listener_socket ();/ * Bind the socket to the client's network address * /    if(Connect (CLIENT_SOCKFD,structSOCKADDR *) &client_addr,sizeof(structSOCKADDR)) = =-1) {Error ("Cant connected to server"); }puts("connected to server\n"); LEN=RECV (Client_sockfd,buf,bufsiz,0);//Receive server-side informationbuf[len]=' + ';printf('%s ', buf);//Print server-side information     while(1)    {//scanf ("%s", buf);Gets (BUF);if(!strcmp(BUF,"Quit")) Break; Len=send (Client_sockfd,buf,strlen(BUF),0); LEN=RECV (Client_sockfd,buf,bufsiz,0); buf[len]=' + ';printf('%s ', buf); } close (CLIENT_SOCKFD);//Close socket         return 0;}

Socket communication under Linux (next)