linux下TCP Socket编程C语言小实例

  几乎是全部按照这个链接上的网址实现的：http://blog.csdn.net/leo115/article/details/8044795

  服务器端的代码：

<span style="font-size:18px;">#include <stdio.h>#include <stdlib.h>#include <strings.h>#include <sys/socket.h>#include <memory.h>#include <unistd.h>#include <netinet/in.h>#include <arpa/inet.h>//处理sighandler_t没有定义的问题#include <signal.h>typedef void (*sighandler_t)(int);sighandler_t signal(int sig, sighandler_t handler);#define PORT 11910  //定义通信的端口号#define BACKLOG 5#define buflen 1024 void process_conn_server(int s);  //跟客户端进行通信的处理函数void sig_pipe(int signo);  //信号处理函数int ss, sc; int main(int argc, char *argv[]){//客户端和服务器端的地址结构struct sockaddr_in server_addr;struct sockaddr_in client_addr;int err;pid_t pid;ss = socket(AF_INET, SOCK_STREAM, 0); //建立一个套接字，TCPif(ss < 0){printf("server: server socket create error\n");return -1;}//注册信号sighandler_t ret;ret =  signal(SIGTSTP, sig_pipe);if(SIG_ERR == ret){printf("signal mount error\n");return -1;}elseprintf("signal mount ok\n");//初始化地址结构memset(&server_addr, 0, sizeof(server_addr));server_addr.sin_family = AF_INET;server_addr.sin_addr.s_addr = htonl(INADDR_ANY); //设置地址 server_addr.sin_port = htons(PORT); //设置端口号//将套接字和地址绑定err = bind(ss, (struct sockaddr *)&server_addr, sizeof(struct sockaddr));if(err < 0){printf("server : bind error\n");return -1;}//设置监听队列的大小err = listen(ss, BACKLOG);if(err < 0){printf("server : listen error\n");return -1;}for(;;){socklen_t addrlen = sizeof(client_addr);//sc为客户端套接字描述符sc = accept(ss, (struct sockaddr *)&client_addr, &addrlen);if(sc < 0) continue;else printf("server : connected\n");pid = fork();if(pid == 0){ //子进程与客户端进行通信close(ss);process_conn_server(sc);}else close(sc);  //客户端继续进行监听}}void process_conn_server(int s){ssize_t size = 0;char buffer[buflen];for(;;){//收到从客户端发来的数据并进行输出for(size = 0; size == 0; size = read(s, buffer, buflen));printf("%s", buffer);if(strcmp(buffer, "quit") == 0){close(s);return;}sprintf(buffer, "%d bytes altogether\n", size);write(s, buffer, strlen(buffer) + 1);}}void sig_pipe(int signo){printf("catch a signal\n");if(signo == SIGTSTP){printf("get SIGTSTP signal");int ret1 = close(ss);int ret2 = close(sc);int ret = ret1 > ret2 ? ret1 : ret2;if(ret == 0) printf("success : close IPC");else if(ret == -1) printf("fail : not close IPC");exit(1);}}</span>

  客户端程序：

<span style="font-size:18px;">#include <stdio.h>#include <strings.h>#include <unistd.h>#include <sys/types.h>#include <sys/socket.h>#include <stdlib.h>#include <memory.h>#include <arpa/inet.h>#include <netinet/in.h>#include <signal.h>typedef void (*sighandler_t)(int);sighandler_t signal(int sig, sighandler_t handler);#define PORT 11910  //端口号#define Buflen 1024void process_conn_client(int s); //客户端进行通信的处理函数void sig_pipe(int signo);int s;int main(int argc, char *argv[]){struct sockaddr_in server_addr; //服务器端的地址结构int err;sighandler_t ret;char server_ip[50] = "";s = socket(AF_INET, SOCK_STREAM, 0);  //建立套接字if(s < 0){printf("client : create socket error\n");return 1;}ret = signal(SIGTSTP, sig_pipe);if(SIG_ERR == ret){printf("signal mount fail\n");return -1;}else printf("signal mount success\n");//初始化服务器端的地址结构memset(&server_addr, 0, sizeof(server_addr));server_addr.sin_family = AF_INET;server_addr.sin_port = htons(PORT);server_addr.sin_addr.s_addr = htonl(INADDR_ANY);//输入服务器的ip地址printf("please input server ip address: \n");read(0, server_ip, 50);server_addr.sin_addr.s_addr = inet_addr(server_ip);//与服务器端进行连接操作err = connect(s, (struct sockaddr *)&server_addr, sizeof(struct sockaddr));if(err == 0) printf("client : connect to server\n");else{printf("client : connect error\n");return -1;}process_conn_client(s);close(s);}void process_conn_client(int s){ssize_t size = 0;char buffer[Buflen];for(;;){memset(buffer, '\0', Buflen);size = read(0, buffer, Buflen);if(size > 0){write(s, buffer, strlen(buffer) + 1);for(size = 0; size == 0; size = read(s, buffer, Buflen));write(1, buffer, strlen(buffer) + 1);}}}void sig_pipe(int signo){printf("Catch a signal\n");if(signo == SIGTSTP){int ret = close(s);if(ret == 0) printf("success : close IPC\n");else if(ret == -1) printf("fail : not close IPC\n");exit(1);}}</span>

  时间有点晚了，要回宿舍，写的比较草，准备明天自己实现一个，客户端输入两个整数，服务器端实现完成两个整数的加法，尝试一下...