转载请加上博文引用：http://i.cnblogs.com/EditPosts.aspx?postid=5733248&update=1
服务端：
1 #include <stdio.h> 2 #include <stdlib.h> 3 #include <errno.h> 4 #include <string.h> 5 #include <netdb.h> 6 #include <time.h> 7 #include <unistd.h> 8 #include <sys/types.h> 9 #include <sys/socket.h> 10 #include <arpa/inet.h> 11 12 int sockfd; 13 14 void do_service(int fd) 15 { 16 long t = time(0); 17 char *s = ctime(&t); 18 write(fd,s,strlen(s)); 19 } 20 void out_client(struct sockaddr_in clientaddr) 21 { 22 char buffer[16]; 23 inet_ntop(AF_INET,&clientaddr.sin_addr.s_addr,buffer,sizeof(clientaddr)); 24 unsigned short port = ntohs(clientaddr.sin_port); 25 printf("client ip:%s (%d)\n",buffer,port); 26 } 27 28 29 int main(int argc,char *argv[]) 30 { 31 if(argc < 2) 32 { 33 fprintf(stderr,"usage: %s port\n",argv[0]); 34 exit(1); 35 } 36 37 //创建套接字 38 sockfd = socket(AF_INET,SOCK_STREAM,0); 39 if(sockfd < 0) 40 { 41 fprintf(stderr,"socket: %s\n",strerror(errno)); 42 exit(1); 43 } 44 45 //设置IP和端口 46 struct sockaddr_in addr; 47 memset(&addr,0,sizeof(addr)); 48 addr.sin_family = AF_INET; 49 addr.sin_port = htons(atoi(argv[1])); 50 addr.sin_addr.s_addr = INADDR_ANY; 51 52 //绑定IP和端口 53 int len = sizeof(addr); 54 if(bind(sockfd,(struct sockaddr*)&addr,len) < 0) 55 { 56 fprintf(stderr,"bind: %s\n",strerror(errno)); 57 exit(1); 58 } 59 60 //开始听 61 if(listen(sockfd,10) < 0) 62 { 63 fprintf(stderr,"listen: %s\n",strerror(errno)); 64 exit(1); 65 } 66 67 while(1) 68 { 69 struct sockaddr_in clientaddr; 70 int c_len = sizeof(clientaddr); 71 int fd = accept(sockfd,(struct sockaddr*)&clientaddr,&c_len); 72 if(fd < 0) 73 { 74 fprintf(stderr,"accept: %s\n",strerror(errno)); 75 continue; 76 } 77 out_client(clientaddr); 78 do_service(fd); 79 close(fd); 80 } 81 return 0; 82 }
编译：
gcc -o server server.c
运行：
./server 6666
客户端：
1 #include <stdio.h> 2 #include <stdlib.h> 3 #include <errno.h> 4 #include <string.h> 5 #include <netdb.h> 6 #include <sys/socket.h> 7 #include <netinet/in.h> 8 #include <arpa/inet.h> 9 #include <unistd.h> 10 11 int sockfd; 12 13 int main(int argc,char *argv[]) 14 { 15 if(argc < 3) 16 { 17 fprintf(stderr,"usage: %s port\n",argv[0]); 18 exit(1); 19 } 20 21 sockfd = socket(AF_INET,SOCK_STREAM,0); 22 if(sockfd < 0) 23 { 24 fprintf(stderr,"socket:%s\n",strerror(errno)); 25 exit(1); 26 } 27 28 struct sockaddr_in sockaddr; 29 memset(&sockaddr,0,sizeof(sockaddr)); 30 sockaddr.sin_family = AF_INET; 31 sockaddr.sin_port = htons(atoi(argv[2])); 32 inet_pton(AF_INET,argv[1],&sockaddr.sin_addr.s_addr); 33 socklen_t len = sizeof(sockaddr); 34 35 if(connect(sockfd,(struct sockaddr*)&sockaddr,len) < 0) 36 { 37 fprintf(stderr,"connect: %s\n",strerror(errno)); 38 exit(1); 39 } 40 char buffer[1024]; 41 memset(buffer,0,sizeof(buffer)); 42 ssize_t n; 43 if((n = read(sockfd,buffer,1024)) < 0) 44 { 45 fprintf(stderr,"read: %s\n",strerror(errno)); 46 exit(1); 47 } 48 else 49 { 50 printf("%s\n",buffer); 51 } 52 53 return 0; 54 }
编译：
gcc -o client client.c
运行：
./client 192.168.0.30 6666
