基于TCP协议的进程间通信

TCP协议是应用在传输层的协议。是一种面向连接的、可靠的协议。

TCP协议的特点：

1）面向字节流。

2）TCP是面向连接的运输层协议

3) 每一条TCP链接只能有两个端点

4）TCP提供可靠交付的服务

5）TCP提供全双工通信

根据TCP协议三次握手，server一直处于监听状态，等接受到client的请求连接（connect）信号，accept该连接。

  server:   1 #include  2 #include  3 #include  4 #include  5 #include  6 #include  7 #include  8 #include  9 #define _BACKLOG 5 10 void usage(char *_proc) 11 { 12     printf("usage: %s,[ip],[proc]",_proc); 13 } 14 int startup(const char *ip,const int port) 15 { 16     int sock = socket(AF_INET,SOCK_STREAM,0); //创建套接字 17     if(sock < 0) 18     { 19         perror("socket"); 20         exit(1); 21     } 22     struct sockaddr_in local; 23     local.sin_family = AF_INET; 24     local.sin_port = htons(port); 25     local.sin_addr.s_addr = inet_addr(ip); 26     if(bind(sock,(struct sockaddr*)&local,sizeof(local))<0) //将IP和端口号绑定 27     { 28         perror("bind"); 29         exit(2); 30     } 31     if(listen(sock,_BACKLOG)<0) //监听是否有进程与之创建连接 32     { 33         perror("listen"); 34         exit(3); 35     } 36     return sock; 37 } 38 void* pthread(void * arg) 39 { 40     int sock = (int)arg; 41     char buf[1024]; 42     while(1) 43     { 44         ssize_t size = read(sock,buf,sizeof(buf)-1); 45         if(size>0) 46         { 47             buf[size] = '\0'; 48         } 49         else if(size==0) 50         { 51             printf("client close...\n"); 52             break; 53         } 54         else 55         { 56             perror("read"); 57             exit(3); 58         } 59         printf("client say: %s\n",buf); 60     } 61     close(sock); 62     return NULL; 63 } 64  65 int main(int argc,char *argv[]) 66 { 67     if(argc != 3) 68     {  69         usage(argv[0]); 70         exit(1); 71     } 72     char *ip = argv[1]; 73     int port = atoi(argv[2]); 74     int listen_sock = startup(ip,port); 75     struct sockaddr_in client; 76     socklen_t len = sizeof(client); 77     while(1) 78     { 79         int new_sock = accept(listen_sock,(struct sockaddr*)&client,&len); 80         if(new_sock<0) 81         { 82             perror("accept"); 83             continue; 84         } 85         printf("get a client... sock %d,ip: %s,port: %d\n",new_sock,inet_nto    a(client.sin_addr),ntohs(client.sin_port)); 86 #ifdef _V1_ //单进程通信 87         char buf[1024]; 88         while(1) 89         { 90             ssize_t size = read(new_sock,buf,sizeof(buf)-1); 91             if(size>0) 92             { 93                 buf[size] = '\0'; 94             } 95             else if(size==0) 96             { 97                 printf("client close...\n"); 98                 break; 99             }100             else101             {102                 perror("read");103                 exit(3);104             }105             printf("client say :%s\n",buf);106         }107 #elif _V2_ //多进程108         pid_t pid = fork();109         if(pid<0)110         {                              111             perror("fork");112             exit(4);113         }114         else if(pid == 0)115         {//child116             close(listen_sock);117             char *_client = inet_ntoa(client.sin_addr);118             char buf[1024];119             while(1)120             {121                 memset(buf,'\0',sizeof(buf));122                 ssize_t size = read(new_sock,buf,sizeof(buf)-1);123                 if(size>0)124                 {125                     buf[size] = '\0';126                 }127                 else if(size==0)128                 {129                     printf("[ip]:%s close...\n",_client);130                     break;131                 }132                 else133                 {134                     perror("read");135                     exit(3);136                 }137                 printf("[ip]:%s say :%s\n",_client,buf);138             }139             close(new_sock);140             exit(0);141         }142         else143         {//father144             close(new_sock);145         }146 #elif _V3_ //多线程147         pthread_t pid;148         pthread_create(&pid,NULL,pthread,(void*)new_sock);149         pthread_detach(pid);150 #else151         printf("default");152 #endif153     }154     return 0;155 }client:   1 #include  2 #include  3 #include  4 #include  5 #include  6 #include  7 #include  8   9 void usage(char *proc) 10 { 11     printf("usage:%s,[remote ip],[remote proc]",proc); 12 } 13 int main(int argc,char *argv[]) 14 { 15     if(argc != 3) 16     { 17         usage(argv[0]); 18         exit(1); 19     } 20     int sock = socket(AF_INET,SOCK_STREAM,0); 21     if(sock<0) 22     { 23         perror("sock"); 24         exit(1); 25     } 26     int port = atoi(argv[2]); 27     char *ip = argv[1]; 28     struct sockaddr_in remote; 29     remote.sin_family = AF_INET; 30     remote.sin_port = htons(port); 31     remote.sin_addr.s_addr = inet_addr(ip); 32  33     int ret = connect(sock,(struct sockaddr*)&remote,sizeof(remote)); 34     if(ret<0) 35     { 36         perror("connect"); 37         exit(2); 38     } 39     char buf[1024]; 40     while(1) 41     { 42         printf("please say: "); 43         scanf("%s",buf); 44         ssize_t size = write(sock,buf,sizeof(buf)-1); 45  46     } 47     return 0; 48 }  结果：[fbl@localhost tcp]$ ./tcp_server 192.168.1.106 8080get a client... sock 4,ip: 192.168.1.106,port: 51708client say: helloclient say: hiclient say: nihaoclient close...^C[fbl@localhost tcp]$ [fbl@localhost tcp]$ ./tcp_client 192.168.1.106 8080please say: helloplease say: hiplease say: nihao please say: ^C[fbl@localhost tcp]$