Linux下兩個程式進行socket通訊的簡單例子

備忘：

這兩個程式，應該是在同一台機器上運行。需要事先建立/home/rangaofei/c_test/目錄。

今天下午學習了一下socket通訊編程這方面的知識，看了看書，找了找網上的講解。雖然還是比較暈，但做的小實驗還是成功了，打算明天再深入研究。

在Ubuntu環境下編寫了兩個簡單的小程式，分別是client.c和server.c。一個作為socket用戶端，另一個作為socket伺服器端。在GCC下編譯通過了，並且通訊也成功了。現將代碼貼在下面：

/****************** 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);
   }
}

注意：這兩個程式運行時，要先運行伺服器端程式，否則會出錯。因為用戶端將無法找到伺服器。伺服器端運行後，將會阻塞以等待用戶端的串連。

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