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 != 3)
    {
        printf("EXE IP PORT");
        exit(1);
    }

    //socket
    int clientfd = socket(AF_INET,SOCK_STREAM,0);
    if(clientfd == -1)
    {
        perror("clientfd");
        exit(1);
    }
    
    struct sockaddr_in serveraddr;
    serveraddr.sin_family = AF_INET;
    serveraddr.sin_addr.s_addr = inet_addr(argv[1]);
    serveraddr.sin_port = htons(atoi(argv[2]));

    if(-1 == connect(clientfd,(struct sockaddr*)&serveraddr,sizeof(struct sockaddr)))
    {
        perror("connect");
        exit(1);
    }
    
    //send
    char send_buf[SIZE]="";
    fgets(send_buf,sizeof(send_buf),stdin);
    send(clientfd,send_buf,strlen(send_buf),0);

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

    char recv_buf[SIZE] = "";
    recv(clientfd,recv_buf,sizeof(recv_buf)-1,0);
    //printf("recv:%s
",recv_buf);
    fwrite(recv_buf,1,strlen(recv_buf),fp);
    
    fclose(fp);


    close(clientfd);




    return 0;
}

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 != 3)
    {
        printf("EXE IP PORT
");
        exit(1);
    }
    //socket
    int serverfd = socket(AF_INET,SOCK_STREAM,0);
    if(serverfd == -1)
    {
        perror("socket");
        exit(1);
    }

    //bind
    struct sockaddr_in serveraddr;
    serveraddr.sin_family = AF_INET;
    serveraddr.sin_addr.s_addr = inet_addr(argv[1]);
    serveraddr.sin_port = htons(atoi(argv[2]));

    if(-1 == bind(serverfd,(struct sockaddr*)&serveraddr,sizeof(struct sockaddr)))
    {
        perror("bind");
        exit(1);
    }

    //listen
    if(-1 == listen(serverfd,10))
    {
        perror("listen");
        exit(1);
    }
    
    //accept
    int clientfd;
    struct sockaddr_in clientaddr;
    socklen_t clientlen = sizeof(clientaddr);

    clientfd = accept(serverfd,(struct sockaddr*)&clientaddr,&clientlen);
    if(clientfd == -1)
    {
        perror("accept");
        exit(1);
    }

    printf("client: ip:%s,port:%d on
",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)-1,0);
    
    sprintf(FULL_PATH,"%s/%s",DOWN_PATH,recv_buf);
    FULL_PATH[strlen(FULL_PATH)-1] = '';
    printf("download file:%s
",FULL_PATH);

    //open file
    FILE* fp = fopen(FULL_PATH,"r");
    if(fp == NULL)
    {
        perror("fopen");
        exit(1);
    }
    
    //read file
    char send_buf[SIZE] = "";
    size_t readn;
    readn = fread(send_buf,1,sizeof(send_buf),fp);
    printf("readn:%d
",readn);

    //send
    size_t sendn;
    sendn = send(clientfd,send_buf,strlen(send_buf),0);
    if(sendn == -1)
    {
        perror("sendn");
        exit(1);
    }

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

    close(clientfd);
    close(serverfd);

    //while(1);
    return 0;
}