linux下的简单的TCP客户端服务器通信程序

#include <sys/types.h> #include <sys/socket.h> #include <stdio.h> #include <stdlib.h> #include <errno.h> #include <string.h> #include <unistd.h> #include <netinet/in.h> #define SERVPORT 3333 #define BACKLOG 10 #define MAX_CONNECTED_NO 10 #define MAXDATASIZE 100 int main() { struct sockaddr_in server_sockaddr,client_sockaddr; int sin_size,recvbytes; int sockfd,client_fd; char buf[MAXDATASIZE]; /*建立socket连接*/ if((sockfd = socket(AF_INET,SOCK_STREAM,0))== -1) { perror("socket"); exit(1); } printf("socket success!,sockfd=%d\n",sockfd); /*设置sockaddr_in 结构体中相关参数*/ server_sockaddr.sin_family=AF_INET; server_sockaddr.sin_port=htons(SERVPORT); server_sockaddr.sin_addr.s_addr=INADDR_ANY; bzero(&(server_sockaddr.sin_zero),8); /*绑定函数bind*/ if(bind(sockfd,(struct sockaddr *)&server_sockaddr,sizeof(struct sockaddr))== -1) { perror("bind"); exit(1); } printf("bind success!\n"); /*调用listen函数*/ if(listen(sockfd,BACKLOG)== -1) { perror("listen"); exit(1); } printf("listening....\n"); /*调用accept函数，等待客户端的连接*/ while(1) { sin_size=sizeof(struct sockaddr); if((client_fd=accept(sockfd,(struct sockaddr *)&client_sockaddr,&sin_size))== -1) { perror("accept"); exit(1); } /*调用recv函数接收客户端的请求*/ if((recvbytes=recv(client_fd,buf,MAXDATASIZE,0))== -1) { perror("recv"); exit(1); } printf("received a connection :%s\n",buf); if(strcmp(buf,"hello\n")==0) { if(send(client_fd,"hello,too",9,0)==-1) { perror("send"); exit(1); } printf("send hello to client\n"); } else break; } close(sockfd); }