服务器端代码如下：

/* ============================================================================ Name : server.c Author : king Version : Copyright : Your copyright notice Description : Hello World in C, Ansi-style ============================================================================ */ #include <stdlib.h> #include <pthread.h> #include <sys/socket.h> #include <sys/types.h> #include <netinet/in.h> #include <arpa/inet.h> /* inet(3) functions */ #include <stdlib.h> #include <errno.h> #include <stdio.h> #include <string.h> int handle(int point); int main(void) { int sfd, ind; struct sockaddr_in addr; struct sockaddr_in clent; char resv[1024], sendbuf[1024]; char buf[1024]; char * myaddr = "192.168.231.128"; int ret; // 返回值设置 socklen_t lent; int pid; addr.sin_family = AF_INET; //IPv4 Internet protocols addr.sin_port = htons(5050); //这里输入服务器端口号 addr.sin_addr.s_addr = inet_addr(myaddr); ; //INADDR_ANY表示本机IP //獲取socket描述符，IPV4asd printf("socket start \n"); sfd = socket(AF_INET, SOCK_STREAM, 0); if (sfd < 0) { printf("socket error \n"); return -1; } printf("bind start \n"); //将套接子与指定端口链接 if (bind(sfd, (struct sockaddr *) &addr, sizeof(struct sockaddr)) < 0) { printf("bind error \n"); return -1; } //监听套接子 printf("listen start \n"); if (listen(sfd, 1024) < 0) { printf("listen error \n"); return -1; } for (;;) { //接受来自客户端的信息 printf("accept start \n"); memset(&clent, 0, sizeof(clent)); lent = sizeof(clent); ind = accept(sfd, (struct sockaddr *) &clent, &lent); if (ind < 0) { printf("accept error %d \n", ind); return -1; } printf("infor \n"); printf("clent addr%s porit %d\n", inet_ntop(AF_INET, &clent.sin_addr, buf, sizeof(buf)), ntohs(clent.sin_port)); pid = fork(); if (pid == 0) { //子进程 close(sfd); handle(ind); } else if (pid < 0) { //error close(ind); } else { //父进程 } } return EXIT_SUCCESS; } int handle(int point) { int retn; char buf[1024]; for (;;) { retn = read(point, buf, sizeof(buf)); if (retn < 0) { printf("read error \n"); close(point); break; } else if (retn == 0) { printf("client exit \n"); close(point); break; } printf("client:%s\n", buf); if (strcmp("exit", buf) == 0) { printf("exit \n"); close(point); return 0; } } return 0; }

客户端代码如下：

/* ============================================================================ Name : client.c Author : king Version : Copyright : Your copyright notice Description : Hello World in C, Ansi-style ============================================================================ */ #include <stdio.h> #include <stdlib.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> /* inet(3) functions */ int handle(int fd); int main(void) { int nsd; char buf[1024]; char * myaddr = "192.168.231.128"; struct sockaddr_in addr; printf("welcome to echo client\n"); nsd = socket(AF_INET, SOCK_STREAM, 0); printf("connect start1 \n"); //bzero(addr, sizeof(*addr)); memset(&addr,0,sizeof(addr)); printf("connect start2 \n"); addr.sin_family = AF_INET; addr.sin_port = htons(5050); addr.sin_addr.s_addr=inet_addr(myaddr); printf("connect start3 \n"); if (connect(nsd, (struct sockaddr *)&addr, sizeof(struct sockaddr)) < 0) { printf("connect error \n"); return -1; } sleep(5); printf("handle start\n"); handle(nsd); close(nsd); return EXIT_SUCCESS; } int handle(int fd) { char sendl[1024], rev[1024]; int retn; for (;;) { memset(sendl,0,sizeof(sendl)); memset(rev,0,sizeof(rev)); if (fgets(sendl, 1024, stdin) == NULL) { break; } // printf("wirte start\n"); write(fd, sendl, strlen(sendl)); read(fd, rev,strlen(rev)); } return 0; }

注意：
int connect(int sockfd, const struct sockaddr *addr,socklen_t addrlen);
记住一定是值 addrlen
accept   socklen_t *addrlen要是一个指针