client.c

linux下

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<sys/socket.h>
#include<netinet/in.h>
#include<arpa/inet.h>
#include<netdb.h>
#include<errno.h>
#include<fcntl.h>

int main(int argc, char *argv[]) 
{
	int sockfd;
	char buffer[1024];
	char buffer2[1024];
	struct sockaddr_in server_addr;
	struct hostent *host;
	int portnumber,nbytes;

	if(argc!=5)
	{
		printf("Please enter the write order!\n");
		exit(1);
	}
	if(strcmp(argv[1],"-i")!=0)
	{
		printf("Please enter the write order!\n");
		exit(1);
	}
	if(strcmp(argv[3],"-p")!=0)
	{
		printf("Please enter the write order!\n");
		exit(1);
	}
	if((host=gethostbyname(argv[2]))==NULL)
	{
		printf("Connect to server error!\n");
		exit(1);
	}
	if((portnumber=atoi(argv[4]))<0)
	{
		printf("Portmap error!");
		exit(1);
	}
	/* 客户程序开始建立sockfd描述符 */
	if((sockfd=socket(AF_INET,SOCK_STREAM,0))==-1)
	{
		printf("Socket connect error!\n");
		exit(1);
	}
	/* 客户程序填充服务端的资料 */
	bzero(&server_addr,sizeof(server_addr));
	server_addr.sin_family=AF_INET;
	server_addr.sin_port=htons(portnumber);
	server_addr.sin_addr=*((struct in_addr *)host->h_addr);
	/* 客户程序发起连接请求 */
	if(connect(sockfd,(struct sockaddr *)(&server_addr),sizeof(struct sockaddr))==-1)
	{
		printf("Connect Error!\n");
		exit(1);
	}
	/* 连接成功了 */
	while(1){
		gets(buffer2);
		buffer2[strlen(buffer2)]='\0';
		write(sockfd, buffer2, strlen(buffer2));
		if((nbytes=read(sockfd,buffer,1024))==-1)
		{
			printf("Read from Server Error!\n");
			exit(1);
		}
		buffer[nbytes]='\0';
		printf("Receive from the server: %s\n",buffer);
		close(sockfd);
		exit(0);
	}
	/* 结束通讯 */
}