linux 下简单的ftp客户端程序

该ftp的客服端是在linux下面写，涉及的东西也比较简单，如前ftp的简单介绍，知道ftp主要的工作流程架构，套接字的创建，还有就是字符串和字符的处理。使用的函数都是比较简单平常易见的，写的时候感觉有将以前学的函数从新巩固一遍。这个简易的ftp客服端只是完成了基本的工作，还有许多的问题有待解决。如：目前最大的问题是使用pasv（被动模式）连接的时候，某些情况下会出现运行错误或同一个运行程序中使用两次pasv的被动连接就是出现运行错误而退出。注意：ftp的测试最好是用linux平台下搭建，连接编码不同ftp会出现错误。

转载请标明出处

代码如下：

/*************************

方便测试ftp:172.16.120.77

author:fengbo

*************************/

#include<stdio.h>

#include<stdlib.h>

#include<sys/socket.h>

#include<string.h>

#include<sys/stat.h>

#include<sys/types.h>

#include<fcntl.h>

#include<netinet/in.h>

#include<unistd.h>

#include<netdb.h>

#include<curses.h>

#defineMAXSIZE

#definebuff

char*data_port;

intport;

char*p,*ptr;

intc_sockfd,d_sockfd;

intread_status,write_status;

//////////////////////////

charread_buf[];//控制端口缓存

charread_d_buf[];//数据端口缓存

charsend_buf[];

charcommand[];

charcom_input[];//输入字符缓存

charpara_input[];

structsockaddr_inserveraddr_d;

///////////////////////////////

staticvoiddisplay_order();//命令提示

staticvoidftp_d_port();//pasv获得端口

staticvoidftp_c_socket(intargc1,char**argv1);//命令端口创建

staticvoidftp_d_socket(char*argv2);//数据端口创建

staticvoidset_pasv(char*argv3);//设置被动模式

///////////////////////////////

staticvoidftp_c_socket(intargc1,char**argv1){

intret,i,com_len=;

intcom_i=,para_i=;

into_file,r_file,w_file;//文件的描述符

char*com_status,*para_status;

structsockaddr_inserveraddr_c;//网络字节序序存的结构体变量

socklen_tsock_size;

chardir_name[];//dir的当前目录

charfile_name[];

charusername[];

charpassword[];

charcatalog[];//需要cd的目录

chardownload_file[];

charmkdir_catalog[];//创建目录

/////////////////////////

sock_size=sizeof(structsockaddr);

serveraddr_c.sin_family=AF_INET;

serveraddr_c.sin_port=htons();

serveraddr_c.sin_addr.s_addr=inet_addr(argv1[]);

memset(&(serveraddr_c.sin_zero),,);

c_sockfd=socket(AF_INET,SOCK_STREAM,);//创建sock套接字

if(c_sockfd<){

perror("creatsocketerror!\n");

return;

}

ret=connect(c_sockfd,(structsockaddr*)&serveraddr_c,sock_size);

if(ret<){

perror("connecterror!\n");

return;

}

printf("connecttheserverFTPsuccessfully!\n");

read_status=read(c_sockfd,read_buf,sizeof(read_buf));//读取ftp的链接欢迎信息

if(read_status==-){

perror("errortogaintheftpwelconmeinformation!\n");

}

printf("theinformation:%s\n",read_buf);

/////////////////login//////////////////////////

printf("--------------------------pleasetologin--------------------------\n");

printf("\n");

printf("***username:");

scanf("%s",username);

getchar();

printf("\n");

printf("***password:");

scanf("%s",password);

getchar();

printf("\n");

printf("--------------------------------------------------------------------\n");

///////////////username//////////////////////////

memset(read_buf,,sizeof(read_buf));

sprintf(send_buf,"USER%s\r\n",username);

write_status=write(c_sockfd,send_buf,strlen(send_buf));

if(write_status==-){

perror("failuretosendtheusername\n");

}

read_status=read(c_sockfd,read_buf,sizeof(read_buf));//读取ftp用户链接的返回信息

if(read_status==-){

perror("errortogaintheftpinformation!\n");

}

if(atoi(read_buf)!=){

printf("errortologintheftp'username'\n");

}

printf("theinformation:%s\n",read_buf);

/////////////////password//////////////////////////

memset(send_buf,,sizeof(send_buf));

memset(read_buf,,sizeof(read_buf));

sprintf(send_buf,"PASS%s\r\n",password);

write_status=write(c_sockfd,send_buf,strlen(send_buf));

if(write_status==-){

perror("failuretosendthepassword\n");

}

read_status=read(c_sockfd,read_buf,sizeof(read_buf));//读取ftp用户链接的返回信息

if(read_status==-){

perror("errortogaintheftpinformation!\n");

}

if(atoi(read_buf)!=){

printf("errortologintheftp'password'\n");

exit(-);

}

printf("theinformation:%s\n",read_buf);

///////////////////设置PASV模式/////////////////////

//set_pasv();

///////////////获取端口函数/////////////////////////

//ftp_d_port();

////////////////////////////发送数据端口请求/////////

//ftp_d_socket(argv1[1]);

//////////////////displaythecommand////////////////

display_order();

///////////////////////////命令控制//////////////////

while(){

printf("%sftp>",username);

scanf("%s",command);//从键盘获取命令和参数

getchar();

com_len=strlen(command);//长度

if(com_len>){

com_status=strstr(command,"-");//取命令和参数分界点

while(command[com_i]!=*com_status){

com_input[com_i]=command[com_i];

com_i++;

}//获取到命令

//printf("%s\n",com_input);

com_status++;

for(para_i=;para_i<=(com_len-com_i-);para_i++){

para_input[para_i]=*com_status;

com_status++;

}//获取到参数

//printf("%s\n",para_input);

com_i=;

}

else{

strcpy(com_input,command);

}

//////////////////////大小写转换///////////////////

/*for(i=0;i<strlen(command);i++){

if(strcmp("command[i]","a")>=0){

command[i]=(command[i]-32);

}

}*/

set_pasv(argv1[]);

if(strcmp(com_input,"PWD")==){

///////////////////////当前路径/////////////////////////////

memset(read_buf,,sizeof(read_buf));

memset(send_buf,,sizeof(send_buf));

sprintf(send_buf,"PWD\r\n");

write_status=write(c_sockfd,send_buf,strlen(send_buf));//命令写入控制套接连接

if(write_status==-){

perror("failuretosendtheinformationfor'PWD'\n");

}

read_status=read(c_sockfd,read_buf,sizeof(read_buf));//读取ftp用户链接的返回信息

if(read_status==-){

perror("errortogaintheftpinformation!\n");

}

//if(atoi(read_buf)!=257){

//printf("errortosetthePASVmodel\n");

//}

printf("%s\n",read_buf);

}

elseif(strcmp(com_input,"DIR")==){

///////////////////////显示目录文件///////////////////

memset(read_buf,,sizeof(read_buf));

memset(send_buf,,sizeof(send_buf));

strcpy(dir_name,para_input);

sprintf(send_buf,"LIST%s\r\n",dir_name);

write_status=write(c_sockfd,send_buf,strlen(send_buf));//命令写入控制套接连接

if(write_status==-){

perror("failuretosendtheinformationfor'LIST'\n");

}

read_status=read(c_sockfd,read_buf,sizeof(read_buf));//读取ftp用户链接的返回信息

if(read_status==-){

perror("errortogaintheftpinformation!\n");

}

printf("%s\n",read_buf);

//if(atoi(read_buf)!=){

//printf("errortosetthePASVmodel\n");

//}

memset(read_d_buf,,sizeof(read_d_buf));

while(read(d_sockfd,read_d_buf,sizeof(read_d_buf))>){

printf("%s",read_d_buf);

memset(read_d_buf,,sizeof(read_d_buf));

}

close(d_sockfd);

memset(&serveraddr_d,,sizeof(serveraddr_d));

}

elseif(strcmp(com_input,"QUIT")==){

/////////////////////////////退出/////////////////////////

close(d_sockfd);

printf("数据端口已关闭\n");

memset(read_buf,,sizeof(read_buf));

memset(send_buf,,sizeof(send_buf));

sprintf(send_buf,"QUIT\r\n");

write_status=write(c_sockfd,send_buf,strlen(send_buf));//命令写入控制套接连接

if(write_status==-){

perror("failuretosendtheinformationfor'RETR'\n");

}

read_status=read(c_sockfd,read_buf,sizeof(read_buf));//读取ftp用户链接的返回信息

if(read_status==-){

perror("errortogaintheftpinformation!\n");

}

//if(atoi(read_buf)!=257){

//printf("errortosetthePASVmodel\n");

//}

printf("%s\n",read_buf);

break;

}

elseif(strcmp(com_input,"GET")==){

/////////////////////////////下载文件/////////////////////

memset(read_buf,,sizeof(read_buf));

memset(send_buf,,sizeof(send_buf));

memset(read_d_buf,,sizeof(read_d_buf));

strcpy(download_file,para_input);

sprintf(send_buf,"RETR%s\r\n",download_file);

write_status=write(c_sockfd,send_buf,strlen(send_buf));

if(write_status==-){

perror("failuretosendtheinformationfor'RETR'\n");

}

read_status=read(c_sockfd,read_buf,sizeof(read_buf));//读取ftp用户链接的返回信息

if(read_status==-){

perror("errortogaintheftpinformation!\n");

}

//if(atoi(read_buf)!=257){

//printf("errortosetthePASVmodel\n");

//}

printf("%s\n",read_buf);

o_file=open(download_file,O_WRONLY|O_CREAT|O_TRUNC,);//创建文件客服端

if(o_file==-){

printf("errortoopenthe%s\n",file_name);

exit(-);

}

while((r_file=read(d_sockfd,read_d_buf,sizeof(read_d_buf)))>){

write(o_file,read_d_buf,r_file);//写入文件

memset(read_d_buf,,sizeof(read_d_buf));

}

printf("transportthefilesuccessfuly!\n");

close(o_file);

close(d_sockfd);

memset(&serveraddr_d,,sizeof(serveraddr_d));

}

elseif(strcmp(com_input,"CD")==){

///////////////////////跳转目录/////////////////////////////

memset(read_buf,,sizeof(read_buf));

memset(send_buf,,sizeof(send_buf));

strcpy(catalog,para_input);

sprintf(send_buf,"CWD%s\r\n",catalog);

write_status=write(c_sockfd,send_buf,strlen(send_buf));//命令写入控制套接连接

if(write_status==-){

perror("failuretosendtheinformationfor'DELE'\n");

}

read_status=read(c_sockfd,read_buf,sizeof(read_buf));//读取ftp用户链接的返回信息

if(read_status==-){

perror("errortogaintheftpinformation!\n");

}

//if(atoi(read_buf)!=257){

//printf("errortosetthePASVmodel\n");

//}

printf("%s\n",read_buf);

}

elseif(strcmp(com_input,"DEL")==){

///////////////////////删除文件/////////////////////////////

memset(read_buf,,sizeof(read_buf));

memset(send_buf,,sizeof(send_buf));

strcpy(file_name,para_input);

sprintf(send_buf,"DELE%s\r\n",file_name);

write_status=write(c_sockfd,send_buf,strlen(send_buf));//命令写入控制套接连接

if(write_status==-){

perror("failuretosendtheinformationfor'DELE'\n");

}

read_status=read(c_sockfd,read_buf,sizeof(read_buf));//读取ftp用户链接的返回信息

if(read_status==-){

perror("errortogaintheftpinformation!\n");

}

//if(atoi(read_buf)!=257){

//printf("errortosetthePASVmodel\n");

//}

printf("%s\n",read_buf);

}

elseif(strcmp(com_input,"MKDIR")==){

///////////////////////创建目录/////////////////////////////

memset(read_buf,,sizeof(read_buf));

memset(send_buf,,sizeof(send_buf));

strcpy(mkdir_catalog,para_input);

sprintf(send_buf,"MKD%s\r\n",mkdir_catalog);

write_status=write(c_sockfd,send_buf,strlen(send_buf));//命令写入控制套接连接

if(write_status==-){

perror("failuretosendtheinformationfor'DELE'\n");

}

read_status=read(c_sockfd,read_buf,sizeof(read_buf));//读取ftp用户链接的返回信息

if(read_status==-){

perror("errortogaintheftpinformation!\n");

}

//if(atoi(read_buf)!=257){

//printf("errortosetthePASVmodel\n");

//}

printf("%s\n",read_buf);

}

else{

printf("***************thecommanderror!****************\n");

display_order();//显示命令

}

}

}

//////////////////////////PASV被动模式设置/////////////////////////////////

staticvoidset_pasv(char*argv3){

memset(send_buf,,sizeof(send_buf));

memset(read_buf,,sizeof(read_buf));

sprintf(send_buf,"PASV\r\n");

write_status=write(c_sockfd,send_buf,strlen(send_buf));

if(write_status==-){

perror("failuretosendtheinformationfor'PASV'\n");

}

read_status=read(c_sockfd,read_buf,sizeof(read_buf));//读取ftp用户链接的返回信息

if(read_status==-){

perror("errortogaintheftpinformation!\n");

}

printf("%s",read_buf);

if(atoi(read_buf)!=){

printf("errortosetthePASVmodel\n");

}

ftp_d_port();//获取端口

ftp_d_socket(argv3);//数据套接字创建

}

/////////////////////////获取端口函数实现///////////////////////////////////

staticvoidftp_d_port(){

char*port_status1,*port_status2,*index,extend,extend_1;

intport_temp1[],port_temp2[];//当时出现错误,变量为int型

intport_i=,port_ii=,count,count_i,count_ii;

inttemp=,temp1=,temp2,port_point;

port_status1=strstr(read_buf,"(");//取“（”里面的

port_status1++;

for(port_point=;port_point<;port_point++){//取第4个逗号位置

port_status2=strstr(port_status1,",");

port_status2++;

port_status1=port_status2;

}

port_status2=strstr(port_status1,",");//取第5个逗号位置

while(port_status1!=port_status2){

extend=*port_status1;

port_temp1[port_i]=(int)(extend-);//获取5~6逗号间数据

port_i++;

port_status1++;

}

port_status2++;

port_status1=port_status2;

port_status2=strstr(port_status1,")");//取")"的位置

while(port_status1!=port_status2){

extend_1=*port_status1;

port_temp2[port_ii]=(extend_1-);//获得")"之前的数据

port_ii++;

port_status1++;

}

count_i=port_i;

for(count=;count<port_i;count++){

if(count_i==){

count_ii=;

}

elseif(count_i==){

count_ii=;

}

elseif(count_i==){

count_ii=;

}

temp=temp+port_temp1[count]*count_ii;//计算p1

count_i--;

}

count_i=port_ii;

for(count=;count<port_ii;count++){

if(count_i==){

count_ii=;

}

elseif(count_i==){

count_ii=;

}

elseif(count_i==){

count_ii=;

}

temp1=temp1+port_temp2[count]*count_ii;//计算p2

count_i--;

}

port=temp*+temp1;//p1*256+p2

printf("theinformation:%s\n",read_buf);

}

//////////////////////////命令提示////////////////////////////////////////

staticvoiddisplay_order(){

printf("****************************************************\n");

printf("youcaninputtheCommand:\n");

printf("DIR,PWD,GET,PUT,QUIT,CD,DEL,MKDIR\n");

printf("attention:命令和参数间用'-'分开\n");

printf("****************************************************\n");

}

///////////////////////////数据传送端口////////////////////////////////////

staticvoidftp_d_socket(char*argv2){

intret_d;

//structsockaddr_inserveraddr_d;

socklen_tsock_d_size;

sock_d_size=sizeof(structsockaddr);

serveraddr_d.sin_family=AF_INET;

serveraddr_d.sin_port=htons(port);

serveraddr_d.sin_addr.s_addr=inet_addr(argv2);

memset(&(serveraddr_d.sin_zero),,);

d_sockfd=socket(AF_INET,SOCK_STREAM,);

if(d_sockfd<){

perror("creatdata_socketerror\n");

exit(-);

}

ret_d=connect(d_sockfd,(structsockaddr*)&serveraddr_d,sock_d_size);

if(ret_d<){

perror("data_connecterror!\n");

exit(-);

}

printf("connecttheFTPdataportsuccessfully!\n");

}

intmain(intargc,char**argv){

ftp_c_socket(argc,argv);

return;

}

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