Unix c 网络编程 TCP

服务器端:

 ===============================================================================================

 #include <stdio.h>

 #include <stdlib.h>

 #include <errno.h>

 #include <string.h>

 #include <netdb.h>

 #include <time.h>



 int sockfd;



 void do_service(fd)

 {

     long t = time(0);

     char *s = ctime(&t);

     write(fd,s,strlen(s));

 }

 void out_client(struct sockaddr_in clientaddr)

 {

     char buffer[16];

     inet_ntop(AF_INET,&clientaddr.sin_addr.s_addr,buffer,sizeof(clientaddr));

     unsigned short port = ntohs(clientaddr.sin_port);

     printf("client ip:%s (%d)\n",buffer,port);

 }





 int main(int argc,char *argv[])

 {

     if(argc < 2)

     {

         fprintf(stderr,"usage: %s port\n",argv[0]);

         exit(1);

     }



     //create socket

     sockfd = socket(AF_INET,SOCK_STREAM,0);

     if(sockfd < 0)

     {

         fprintf(stderr,"socket: %s\n",strerror(errno));

         exit(1);

     }



     //set ip and port

     struct sockaddr_in addr;

     memset(&addr,0,sizeof(addr));

     addr.sin_family = AF_INET;

     addr.sin_port = htons(atoi(argv[1]));

     addr.sin_addr.s_addr = INADDR_ANY; 



     //bind ip and port

     int len = sizeof(addr);

     if(bind(sockfd,(struct sockaddr*)&addr,len) < 0)

     {

         fprintf(stderr,"bind: %s\n",strerror(errno));

         exit(1);

     }



     //begin to listen

     if(listen(sockfd,10) < 0)

     {

         fprintf(stderr,"listen: %s\n",strerror(errno));

         exit(1);

     }



     while(1)

     {

         struct sockaddr_in clientaddr;

         int c_len = sizeof(clientaddr);

         int fd = accept(sockfd,(struct sockaddr*)&clientaddr,&c_len);

         if(fd < 0)

         {

             fprintf(stderr,"accept: %s\n",strerror(errno));

             continue;

         }

         out_client(clientaddr);

         do_service(fd);

         close(fd);



     }

     return 0;

 }



 ==============================================================================================



 客户端:

 ==============================================================================================

 #include <stdio.h>

 #include <stdlib.h>

 #include <errno.h>

 #include <string.h>

 #include <netdb.h>



 int sockfd;



 int main(int argc,char *argv[])

 {

     if(argc < 3)

     {

         fprintf(stderr,"usage: %s port\n",argv[0]);

         exit(1);

     }



     sockfd = socket(AF_INET,SOCK_STREAM,0);

     if(sockfd < 0)

     {

         fprintf(stderr,"socket:%s\n",strerror(errno));

         exit(1);

     }



     struct sockaddr_in sockaddr;

     memset(&sockaddr,0,sizeof(sockaddr));

     sockaddr.sin_family = AF_INET;

     sockaddr.sin_port = htons(atoi(argv[2]));

     inet_pton(AF_INET,argv[1],&sockaddr.sin_addr.s_addr);

     socklen_t len = sizeof(sockaddr);



     if(connect(sockfd,(struct sockaddr*)&sockaddr,len) < 0)

     {

         fprintf(stderr,"connect: %s\n",strerror(errno));

         exit(1);

     }

     char buffer[1024];

     memset(buffer,0,sizeof(buffer));

     ssize_t n;

     if((n = read(sockfd,buffer,1024)) < 0)

     {

         fprintf(stderr,"read: %s\n",strerror(errno));

         exit(1);

     }

     else

     {

         printf("%s\n",buffer);

     }



     return 0;

 }