_tcp_file_cli.c

linux下的多个网络通讯的例子 可多参考下

/* TCP 文件接收客户端 */
#include <stdio.h>                                       
#include <stdlib.h>                                      
#include <errno.h>                                       
#include <string.h>                                      
#include <sys/types.h>                                   
#include <netinet/in.h>                                  
#include <sys/socket.h>                                  
#include <sys/wait.h>   

#define FILE_MAX_LEN 64
	
#define DEFAULT_SVR_PORT 2828
	
main(int argc,char * argv[])
{
	
	int sockfd,numbytes;
	char buf[1024],filename[FILE_MAX_LEN+1];
	char ip_addr[64];
	
	struct hostent *he;
	struct sockaddr_in their_addr;
	int i = 0,len,total; 
	unsigned short port;
	
		FILE * file = NULL;
		

		if(argc <2)
			{
				 printf("need a server ip \n");
				 exit;
			}
			
			strncpy(ip_addr,argv[1],sizeof(ip_addr));
		
		 port = DEFAULT_SVR_PORT;
		 
		  if(argc >=3)
		  {
		  	 port = (unsigned short)atoi(argv[2]);
		  }	       
		
		
		//做域名解析(DNS)
//		he = gethostbyname(argv[1]);    
		
		                      
		//第一步:建立一个TCP套接字                                   
		if((sockfd = socket(AF_INET,SOCK_STREAM,0))==-1) {    
			perror("socket");                                     
			exit(1);                                              
		}      
		
		                                               
		//第二步:设置服务器地址和端口2323
		// 
		memset(&their_addr,0,sizeof(their_addr)); 
		               
		their_addr.sin_family = AF_INET;                      
		their_addr.sin_port = htons(port);                    
		their_addr.sin_addr.s_addr = inet_addr(ip_addr);	
			
	//	their_addr.sin_addr = *((struct in_addr *)he->h_addr);
	//	bzero(&(their_addr.sin_zero),8);   
		
		printf("connect server %s:%d\n",ip_addr,port);
		
		/*第三步:用connect 和服务器建立连接 ,
		 注意,这里没有使用本地端口,将由协议栈自动分配一个端口                                   */
		if(connect(sockfd,(struct sockaddr *)&their_addr,     
		sizeof(struct sockaddr))                              
		==-1){                                                
			perror("connect");                                    
			exit(1);                                              
		}
		
		if(send(sockfd,"hello",6,0)< 0)
		{
			 	perror("send ");                                    
			exit(1);    
		}
		
		/* 接收文件名,为编程简单,假设前64字节固定是文件名,不足用0来增充 */
			total = 0;
		while(total< FILE_MAX_LEN){
			 /* 注意这里的接收buffer长度,始终是未接收文件名剩下的长度,*/
			 	len = recv(sockfd,filename+total,(FILE_MAX_LEN - total),0);
			 if(len <= 0)
			 	  break;
			 total += len ;	  
		}
		
		/* 接收文件名出错 ? */
			if(total != FILE_MAX_LEN){
				perror("failure file name");
				 exit(-3);
			}
			
		printf("recv file %s.....\n",filename);
		
		file = fopen(filename,"wb");
		//file = fopen("/home/hxy/abc.txt","wb");
		if(file == NULL)
			{
				printf("create file %s failure",filename);
				perror("create:");
				exit(-3);
			}
		
		//接收文件数据
		printf("recv begin\n");
		
		total = 0;
		while(1)
		{
			 len = recv(sockfd,buf,sizeof(buf),0);
			 if(len<= 0)
			 	  break;
			 	  
			 total += len;
			 	  
			//写入本地文件 	  
			 fwrite(buf,1,len,file);
		}
		
		fclose(file);
		printf("recv file %s success total lenght %d\n",filename,total);
		
		
		//第六步:关闭socket                                                        
		close(sockfd);  
		
}