FTP 1.0

自己写的可以实现文件的下载（必须自己知道文件名），还有很多要优化。

譬如：不能看可以下载的文件，输入错误无法处理，不能处理多个用户，每次只能下载一个结束，服务器没有完成守护进程；没有用函数封装，简化main程序。

高级功能:支持文件夹选择下载，断点续传，尝试用多线程，多进程，线程池处理多个请求。

 客户端代码：
 头文件
 #ifndef __CLIENT_COMMON__
 #define __CLIENT_COMMON__

 #include<stdio.h>
 #include<stdlib.h>
 #include<string.h>

 #include<sys/types.h>
 #include<sys/socket.h>

 #include<netinet/in.h>
 #include<arpa/inet.h>

 #include<unistd.h>
 #include<fcntl.h>

 #define SIZE 1024
 #define DOWN_PATH "/home/luolizhi/Downloads"

 #endif

 client main

 #include"client_common.h"

 int main(int argc, char* argv[])    //serverip port
 {
     if(argc != )
     {
         printf("EXE IP PORT");
         exit();
     }

     //socket
     int clientfd = socket(AF_INET,SOCK_STREAM,);
     if(clientfd == -)
     {
         perror("clientfd");
         exit();
     }

     struct sockaddr_in serveraddr;
     serveraddr.sin_family = AF_INET;
     serveraddr.sin_addr.s_addr = inet_addr(argv[]);
     serveraddr.sin_port = htons(atoi(argv[]));

     if(- == connect(clientfd,(struct sockaddr*)&serveraddr,sizeof(struct sockaddr)))
     {
         perror("connect");
         exit();
     }

     //send
     char send_buf[SIZE]="";
     fgets(send_buf,sizeof(send_buf),stdin);
     send(clientfd,send_buf,strlen(send_buf),);

     //recv
     /*
     char FULL_PATH[SIZE]="";
     sprintf(FULL_PATH,"%s/%s",DOWN_PATH,send_buf);
     FULL_PATH[strlen(FULL_PATH)-1]='\0';
 */
     send_buf[strlen(send_buf)-]='\0';
     FILE* fp = fopen(send_buf,"w");

     char recv_buf[SIZE] = "";
     recv(clientfd,recv_buf,sizeof(recv_buf)-,);
     //printf("recv:%s\n",recv_buf);
     fwrite(recv_buf,,strlen(recv_buf),fp);

     fclose(fp);

     close(clientfd);

     return ;
 }

高级功能：实现文件夹选择下载，断点续传。（目前实现由困难）

 服务器端代码：

 头文件
 #ifndef __SERVER_COMMON__
 #define __SERVER_COMMON__

 #include<stdio.h>
 #include<stdlib.h>
 #include<string.h>
                         //socket
 #include<sys/types.h>
 #include<sys/socket.h>
                         //inet
 #include<netinet/in.h>
 #include<arpa/inet.h>
                         //FILE
 #include<sys/types.h>
 #include<sys/stat.h>
 #include<fcntl.h>

 #define DOWN_PATH "/home/luolizhi/Downloads"
 #define SIZE 1024

 void recvn(int sfd,int len);
 void sendn(int sfd,int len);

 #endif

 main 程序
 #include"server_common.h"

 int main(int argc, char* argv[])    //ip port
 {
     if(argc != )
     {
         printf("EXE IP PORT\n");
         exit();
     }
     //socket
     int serverfd = socket(AF_INET,SOCK_STREAM,);
     if(serverfd == -)
     {
         perror("socket");
         exit();
     }

     //bind
     struct sockaddr_in serveraddr;
     serveraddr.sin_family = AF_INET;
     serveraddr.sin_addr.s_addr = inet_addr(argv[]);
     serveraddr.sin_port = htons(atoi(argv[]));

     if(- == bind(serverfd,(struct sockaddr*)&serveraddr,sizeof(struct sockaddr)))
     {
         perror("bind");
         exit();
     }

     //listen
     if(- == listen(serverfd,))
     {
         perror("listen");
         exit();
     }

     //accept
     int clientfd;
     struct sockaddr_in clientaddr;
     socklen_t clientlen = sizeof(clientaddr);

     clientfd = accept(serverfd,(struct sockaddr*)&clientaddr,&clientlen);
     if(clientfd == -)
     {
         perror("accept");
         exit();
     }

     printf("client: ip:%s,port:%d on\n",inet_ntoa(clientaddr.sin_addr),ntohs(clientaddr.sin_port));

     //recv
     char recv_buf[SIZE] = "";
     char FULL_PATH[SIZE] = "";

     recv(clientfd,recv_buf,sizeof(recv_buf)-,);

     sprintf(FULL_PATH,"%s/%s",DOWN_PATH,recv_buf);
     FULL_PATH[strlen(FULL_PATH)-] = '\0';
     printf("download file:%s\n",FULL_PATH);

     //open file
     FILE* fp = fopen(FULL_PATH,"r");
     if(fp == NULL)
     {
         perror("fopen");
         exit();
     }

     //read file
     char send_buf[SIZE] = "";
     size_t readn;
     readn = fread(send_buf,,sizeof(send_buf),fp);
     printf("readn:%d\n",readn);

     //send
     size_t sendn;
     sendn = send(clientfd,send_buf,strlen(send_buf),);
     if(sendn == -)
     {
         perror("sendn");
         exit();
     }

     printf("sendn:%d\n",sendn);

     close(clientfd);
     close(serverfd);

     //while(1);
     return ;
 }