/* * client * tcp * 文字聊天 */#include <stdio.h>#include <string.h>#include <errno.h>#include <sys/socket.h>#include <resolv.h>#include <stdlib.h>#include <netinet/in.h>#include <arpa/inet.h>#include <unistd.h>#define MAXBUF 1024int main(int argc, char **argv){	int sockfd, len;	struct sockaddr_in dest;	char buffer[MAXBUF + 1];		if (argc != 3) {		printf("參數(shù)格式錯(cuò)誤！正確用法如下：\n\t\t%s IP地址 端口\n\t比如:\t%s 127.0.0.1 80\n此程序用來(lái)從某個(gè) IP 地址的服務(wù)器某個(gè)端口接收最多 MAXBUF 個(gè)字節(jié)的消息",		argv[0], argv[0]);		exit(0);	}		/* 創(chuàng)建一個(gè) socket 用于 tcp 通信 */	if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {		perror("Socket");		exit(errno);	}	printf("socket created\n");		/* 初始化服務(wù)器端（對(duì)方）的地址和端口信息,第一個(gè)參數(shù)為地址,第二個(gè)參數(shù)為端口號(hào)*/	bzero(&dest, sizeof(dest));	dest.sin_family = AF_INET;	dest.sin_port = htons(atoi(argv[2]));	if (inet_aton(argv[1], (struct in_addr *) &dest.sin_addr.s_addr) == 0) {		perror(argv[1]);		exit(errno);	}	printf("address created\n");		/* 連接服務(wù)器 */	if (connect(sockfd, (struct sockaddr *) &dest, sizeof(dest)) != 0) {		perror("Connect ");		exit(errno);	}	printf("server connected\n");		while (1) {		/* 接收對(duì)方發(fā)過(guò)來(lái)的消息，最多接收 MAXBUF 個(gè)字節(jié) */		bzero(buffer, MAXBUF + 1);		/* 接收服務(wù)器來(lái)的消息 */		len = recv(sockfd, buffer, MAXBUF, 0);		if (len > 0)			printf("接收消息成功:'%s'，共%d個(gè)字節(jié)的數(shù)據(jù)\n",buffer, len);		else {			if (len < 0)				printf("消息接收失敗！錯(cuò)誤代碼是%d，錯(cuò)誤信息是'%s'\n",errno, strerror(errno));			else				printf("對(duì)方退出了，聊天終止！\n");			break;		}		bzero(buffer, MAXBUF + 1);		printf("請(qǐng)輸入要發(fā)送給對(duì)方的消息：");		fgets(buffer, MAXBUF, stdin);		if (!strncasecmp(buffer, "quit", 4)) {			printf("自己請(qǐng)求終止聊天！\n");			break;		}		/* 發(fā)消息給服務(wù)器 */		len = send(sockfd, buffer, strlen(buffer) - 1, 0);		if (len < 0) {			printf("消息'%s'發(fā)送失敗！錯(cuò)誤代碼是%d，錯(cuò)誤信息是'%s'\n",buffer, errno, strerror(errno));			break;		} 		else			printf("消息：%s\t發(fā)送成功，共發(fā)送了%d個(gè)字節(jié)！\n",buffer, len);	}		/* 關(guān)閉連接 */	close(sockfd);		return 0;}