linux c socket server client 实例

client.c

#include <stdio.h>
          #include <sys/socket.h>
          #include <arpa/inet.h>
          #include <stdlib.h>
          #include <string.h>
          #include <unistd.h>
          #include <netinet/in.h>

          #define BUFFSIZE 32
          void Die(char *mess) { perror(mess); exit(1); }
 int main(int argc, char *argv[]) {
            int sock;
            struct sockaddr_in echoserver;
            char buffer[BUFFSIZE];
            unsigned int echolen;
            int received = 0;

            if (argc != 4) {
              fprintf(stderr, "USAGE: TCPecho <server_ip> <word> <port>\n");
              exit(1);
            }
            /* Create the TCP socket */
            if ((sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) {
              Die("Failed to create socket");
            }


            /* Construct the server sockaddr_in structure */
            memset(&echoserver, 0, sizeof(echoserver));       /* Clear struct */
            echoserver.sin_family = AF_INET;                  /* Internet/IP */
            echoserver.sin_addr.s_addr = inet_addr(argv[1]);  /* IP address */
            echoserver.sin_port = htons(atoi(argv[3]));       /* server port */
            /* Establish connection */
            if (connect(sock,
                        (struct sockaddr *) &echoserver,
                        sizeof(echoserver)) < 0) {
              Die("Failed to connect with server");
            }


 /* Send the word to the server */
            echolen = strlen(argv[2]);
            if (send(sock, argv[2], echolen, 0) != echolen) {
              Die("Mismatch in number of sent bytes");
            }
            /* Receive the word back from the server */
            fprintf(stdout, "Received: ");
            while (received < echolen) {
              int bytes = 0;
              if ((bytes = recv(sock, buffer, BUFFSIZE-1, 0)) < 1) {
                Die("Failed to receive bytes from server");
              }
              received += bytes;
              buffer[bytes] = '\0';        /* Assure null terminated string */
              fprintf(stdout, buffer);
            }


fprintf(stdout, "\n");
         close(sock);
         exit(0);
       }

　　

server.c

#include <stdio.h>
          #include <sys/socket.h>
          #include <arpa/inet.h>
          #include <stdlib.h>
          #include <string.h>
          #include <unistd.h>
          #include <netinet/in.h>

          #define MAXPENDING 5    /* Max connection requests */
          #define BUFFSIZE 32
          void Die(char *mess) { perror(mess); exit(1); }
 void HandleClient(int sock) {
            char buffer[BUFFSIZE];
            int received = -1;
            /* Receive message */
            if ((received = recv(sock, buffer, BUFFSIZE, 0)) < 0) {
              Die("Failed to receive initial bytes from client");
            }
            /* Send bytes and check for more incoming data in loop */
            while (received > 0) {
              /* Send back received data */
              if (send(sock, buffer, received, 0) != received) {
                Die("Failed to send bytes to client");
              }
              /* Check for more data */
              if ((received = recv(sock, buffer, BUFFSIZE, 0)) < 0) {
                Die("Failed to receive additional bytes from client");
              }
            }
            close(sock);
          }

  int main(int argc, char *argv[]) {
            int serversock, clientsock;
            struct sockaddr_in echoserver, echoclient;

            if (argc != 2) {
              fprintf(stderr, "USAGE: echoserver <port>\n");
              exit(1);
            }
            /* Create the TCP socket */
            if ((serversock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) {
              Die("Failed to create socket");
            }
            /* Construct the server sockaddr_in structure */
            memset(&echoserver, 0, sizeof(echoserver));       /* Clear struct */
            echoserver.sin_family = AF_INET;                  /* Internet/IP */
            echoserver.sin_addr.s_addr = htonl(INADDR_ANY);   /* Incoming addr */
            echoserver.sin_port = htons(atoi(argv[1]));       /* server port */

       /* Bind the server socket */
          if (bind(serversock, (struct sockaddr *) &echoserver,
                                       sizeof(echoserver)) < 0) {
            Die("Failed to bind the server socket");
          }
          /* Listen on the server socket */
          if (listen(serversock, MAXPENDING) < 0) {
            Die("Failed to listen on server socket");
          }
             /* Run until cancelled */
            while (1) {
              unsigned int clientlen = sizeof(echoclient);
              /* Wait for client connection */
              if ((clientsock =
                   accept(serversock, (struct sockaddr *) &echoclient,
                          &clientlen)) < 0) {
                Die("Failed to accept client connection");
              }
              fprintf(stdout, "Client connected: %s\n",
                              inet_ntoa(echoclient.sin_addr));
              HandleClient(clientsock);
            }
          }
          

　　

使用：

./server 8080
./client 127.0.0.1 "nihao" 8080


server:
*******output*********
 Client connected: 127.0.0.1 


client:
*******output***********
Received: nihao

　

参考资料：http://www.ibm.com/developerworks/cn/education/linux/l-sock/section2.html