server.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,new_fd;
	struct sockaddr_in server_addr;
	struct sockaddr_in client_addr;
	int sin_size,portnumber;
	char buffer[1024];

	if(argc!=3)
	{
		printf("Please enter the write order!\n");
		exit(1);
	}
	if((portnumber=atoi(argv[2]))<0)
	{
		printf("Please enter the write order!\n");
		exit(1);
	}
	if(strcmp(argv[1],"-p")!=0)
	{
		printf("Please enter the write order!\n");
		exit(1);
	}
/* 服务器端开始建立socket描述符 */
	if((sockfd=socket(AF_INET,SOCK_STREAM,0))==-1)
	{
		printf("Server socket error!\n");
		exit(1);
	}
	/* 服务器端填充 sockaddr结构 */
	bzero(&server_addr,sizeof(struct sockaddr_in));
	server_addr.sin_family=AF_INET;
	server_addr.sin_addr.s_addr=htonl(INADDR_ANY);
	server_addr.sin_port=htons(portnumber);
	/* 捆绑sockfd描述符 */
	if(bind(sockfd,(struct sockaddr *)(&server_addr),sizeof(struct sockaddr))==-1)
	{
		printf("Bind error!\n");
		exit(1);
	}
	/* 监听sockfd描述符 */
	if(listen(sockfd,5)==-1)
	{
		printf("Listen error!\n");
		exit(1);
	}
	int ii = 0;
	while(1)
	{
		/* 服务器阻塞,直到客户程序建立连接 */
		for(ii=0; ii<1024; ii++)
		{
			buffer[ii]='\0';
		}
		sin_size=sizeof(struct sockaddr_in);
		new_fd=accept(sockfd,(struct sockaddr *)(&client_addr),&sin_size);
		if(new_fd<0)
		{
			printf("Accept error!\n");
			exit(1);
		}
		fprintf(stderr,"Server get connection from %s\n", inet_ntoa(client_addr.sin_addr));
		if(read(new_fd, buffer,1024))
		{
			buffer[strlen(buffer)]='\0';
			fprintf(stdout,"%d\t%s\n",strlen(buffer),buffer);
			if(write(new_fd,buffer,strlen(buffer))==-1)
			{
				printf("Write back message Error!\n");
				exit(1);
			}
		}
		/* 结束本次通讯 */
		close(new_fd);
	/* 循环下一个 */
	}
	close(sockfd);
	exit(0);
}