Linux Socket C语言网络编程：Pthread Socket [code from GitHub, for study]

/*
 * config.h 包含该tcp/ip套接字编程所需要的基本头文件，与server.c client.c位于同
一目录下
*/#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>
#include <errno.h>
#include <netinet/in.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <pthread.h>const int MAX_LINE = 2048;
const int PORT = 6001;
const int BACKLOG = 10;
const int LISTENQ = 6666;
const int MAX_CONNECT = 20;

/*
*  服务器端代码实现
*/#include "config.h"/*处理接收客户端消息函数*/
void *recv_message(void *fd)
{int sockfd = *(int *)fd;while(1){char buf[MAX_LINE];memset(buf , 0 , MAX_LINE);int n;if((n = recv(sockfd , buf , MAX_LINE , 0)) == -1){perror("recv error.\n");exit(1);}//ifbuf[n] = '\0';		//若收到的是exit字符，则代表退出通信if(strcmp(buf , "byebye.") == 0){printf("Client closed.\n");close(sockfd);exit(1);}//ifprintf("\nClient: %s\n", buf);}//while
}int main()
{//声明套接字int listenfd , connfd;socklen_t clilen;//声明线程IDpthread_t recv_tid , send_tid;//定义地址结构struct sockaddr_in servaddr , cliaddr;/*(1) 创建套接字*/if((listenfd = socket(AF_INET , SOCK_STREAM , 0)) == -1){perror("socket error.\n");exit(1);}//if/*(2) 初始化地址结构*/bzero(&servaddr , sizeof(servaddr));servaddr.sin_family = AF_INET;servaddr.sin_addr.s_addr = htonl(INADDR_ANY);servaddr.sin_port = htons(PORT);/*(3) 绑定套接字和端口*/if(bind(listenfd , (struct sockaddr *)&servaddr , sizeof(servaddr)) < 0){perror("bind error.\n");exit(1);}//if/*(4) 监听*/if(listen(listenfd , LISTENQ) < 0){perror("listen error.\n");exit(1);}//if/*(5) 接受客户请求，并创建线程处理*/clilen = sizeof(cliaddr);if((connfd = accept(listenfd , (struct sockaddr *)&cliaddr , &clilen)) < 0){perror("accept error.\n");exit(1);}//ifprintf("server: got connection from %s\n", inet_ntoa(cliaddr.sin_addr));/*创建子线程处理该客户链接接收消息*/if(pthread_create(&recv_tid , NULL , recv_message, &connfd) == -1){perror("pthread create error.\n");exit(1);}//if/*处理服务器发送消息*/char msg[MAX_LINE];memset(msg , 0 , MAX_LINE);while(fgets(msg , MAX_LINE , stdin) != NULL)	{	if(strcmp(msg , "exit\n") == 0){printf("byebye.\n");memset(msg , 0 , MAX_LINE);strcpy(msg , "byebye.");send(connfd , msg , strlen(msg) , 0);close(connfd);exit(0);}//ifif(send(connfd , msg , strlen(msg) , 0) == -1){perror("send error.\n");exit(1);}//if		}//while
}

/*
* 客户端代码
*/
#include "config.h"/*处理接收服务器消息函数*/
void *recv_message(void *fd)
{int sockfd = *(int *)fd;while(1){char buf[MAX_LINE];memset(buf , 0 , MAX_LINE);int n;if((n = recv(sockfd , buf , MAX_LINE , 0)) == -1){perror("recv error.\n");exit(1);}//ifbuf[n] = '\0';//若收到的是exit字符，则代表退出通信if(strcmp(buf , "byebye.") == 0){printf("Server is closed.\n");close(sockfd);exit(0);}//ifprintf("\nServer: %s\n", buf);}//while
}int main(int argc , char **argv)
{/*声明套接字和链接服务器地址*/int sockfd;pthread_t recv_tid , send_tid;struct sockaddr_in servaddr;/*判断是否为合法输入*/if(argc != 2){perror("usage:tcpcli <IPaddress>");exit(1);}//if/*(1) 创建套接字*/if((sockfd = socket(AF_INET , SOCK_STREAM , 0)) == -1){perror("socket error");exit(1);}//if/*(2) 设置链接服务器地址结构*/bzero(&servaddr , sizeof(servaddr));servaddr.sin_family = AF_INET;servaddr.sin_port = htons(PORT);if(inet_pton(AF_INET , argv[1] , &servaddr.sin_addr) < 0){printf("inet_pton error for %s\n",argv[1]);exit(1);}//if/*(3) 发送链接服务器请求*/if( connect(sockfd , (struct sockaddr *)&servaddr , sizeof(servaddr)) < 0){perror("connect error");exit(1);}//if	/*创建子线程处理该客户链接接收消息*/if(pthread_create(&recv_tid , NULL , recv_message, &sockfd) == -1){perror("pthread create error.\n");exit(1);}//if	/*处理客户端发送消息*/char msg[MAX_LINE];memset(msg , 0 , MAX_LINE);while(fgets(msg , MAX_LINE , stdin) != NULL)	{if(strcmp(msg , "exit\n") == 0){printf("byebye.\n");memset(msg , 0 , MAX_LINE);strcpy(msg , "byebye.");send(sockfd , msg , strlen(msg) , 0);close(sockfd);exit(0);}//ifif(send(sockfd , msg , strlen(msg) , 0) == -1){perror("send error.\n");exit(1);}//if}//while
}