项目地址：https://github.com/gudipati/FTP-ClientServer

实现的功能

使用以下命令，能够实现对应的功能：

  • put ：将名为 filename 的文件传送到服务器
  • get ：从服务器下载名为 filename 的文件
  • ls：列出服务器当前路径下的所有文件
  • cd：：切换服务器进入 目录
  • pwd：展示服务器当前路径
  • !ls：展示客户端当前路径下的所有文件
  • !cd ：切换客户端进入 目录
  • !pwd：展示客户端当前的路径
  • quit：退出客户端 FTP 会话，返回 Unix 提示符

代码

服务器端

服务器端代码 server.cpp

  1. #include <iostream>
  2. #include <stdlib.h>
  3. #include <stdio.h>
  4. #include <sys/types.h>
  5. #include <sys/socket.h>
  6. #include <netinet/in.h>
  7. #include <string.h>
  8. #include <fstream>
  9. #include <unistd.h>
  10. using namespace std;
  12. int create_socket(int);
  13. int accept_conn(int);
  15. #ifdef WINDOWS
  16.     #include <direct.h>
  17.     #define GetCurrentDir _getcwd
  18. #else
  19.     #include <unistd.h>
  20.     #define GetCurrentDir getcwd
  21.  #endif
  23. #define MAXLINE 4096 /*max text line length*/
  24. #define LISTENQ 8 /*maximum number of client connections*/
  26. int main (int argc, char **argv)
  27. {
  28.  int listenfd, connfd, n;
  29.  pid_t childpid;
  30.  socklen_t clilen;
  31.  char buf[MAXLINE];
  32.  struct sockaddr_in cliaddr, servaddr;
  34.  if (argc !=2) {                        //validating the input
  35.   cerr<<"Usage: ./a.out <port number>"<<endl;
  36.   exit(1);
  37.  }
  40.  //Create a socket for the soclet
  41.  //If sockfd<0 there was an error in the creation of the socket
  42.  if ((listenfd = socket (AF_INET, SOCK_STREAM, 0)) <0) {
  43.   cerr<<"Problem in creating the socket"<<endl;
  44.   exit(2);
  45.  }
  48.  //preparation of the socket address
  49.  servaddr.sin_family = AF_INET;
  50.  servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
  51.  if(atoi(argv[1])<=1024){
  52.     cerr<<"Port number must be greater than 1024"<<endl;
  53.     exit(2);
  54.  }
  55.  servaddr.sin_port = htons(atoi(argv[1]));
  57.  //bind the socket
  58.  bind (listenfd, (struct sockaddr *) &servaddr, sizeof(servaddr));
  60.  //listen to the socket by creating a connection queue, then wait for clients
  61.  listen (listenfd, LISTENQ);
  63.  cout<<"Server running...waiting for connections."<<endl;
  65.  for ( ; ; ) {
  67.   clilen = sizeof(cliaddr);
  68.   //accept a connection
  69.   connfd = accept (listenfd, (struct sockaddr *) &cliaddr, &clilen);
  71.   cout<<"Received request..."<<endl;
  73.   if ( (childpid = fork ()) == 0 ) {//if it’s 0, it’s child process
  75.   cout<<"Child created for dealing with client requests"<<endl;
  77.   //close listening socket
  78.   close (listenfd);
  79.   int data_port=1024;                        //for data connection
  80.   while ( (n = recv(connfd, buf, MAXLINE,0)) > 0)  {
  81.    cout<<"String received from client: "<<buf;
  82.    char *token,*dummy;
  83.    dummy=buf;
  84.    token=strtok(dummy," ");
  86.    if (strcmp("quit\n",buf)==0)  {
  87.        cout<<"The client has quit\n";
  88.    }
  90.    if (strcmp("ls\n",buf)==0)  {
  91.     FILE *in;
  92.     char temp[MAXLINE],port[MAXLINE];
  93.     int datasock;
  94.     data_port=data_port+1;
  95.     if(data_port==atoi(argv[1])){
  96.         data_port=data_port+1;
  97.     }
  98.     sprintf(port,"%d",data_port);
  99.     datasock=create_socket(data_port);            //creating socket for data connection
  100.     send(connfd, port,MAXLINE,0);                //sending data connection port no. to client
  101.     datasock=accept_conn(datasock);                 //accepting connection from client
  102.     if(!(in = popen("ls", "r"))){
  103.         cout<<"error"<<endl;
  104.     }
  105.     while(fgets(temp, sizeof(temp), in)!=NULL){
  106.         send(datasock,"1",MAXLINE,0);
  107.         send(datasock, temp, MAXLINE, 0);
  109.     }
  110.     send(datasock,"0",MAXLINE,0);
  111.     pclose(in);
  112.     //cout<<"file closed\n";
  113.    }
  115.    if (strcmp("pwd\n",buf)==0)  {
  116.        char curr_dir[MAXLINE];
  118.     GetCurrentDir(curr_dir,MAXLINE-1);
  119.     send(connfd, curr_dir, MAXLINE, 0);
  120.     //cout<<curr_dir<<endl;
  121.    }
  123.    if (strcmp("cd",token)==0)  {
  124.     token=strtok(NULL," \n");
  125.     cout<<"Path given is: "<<token<<endl;
  126.     if(chdir(token)<0){
  127.         send(connfd,"0",MAXLINE,0);
  128.     }
  129.     else{
  130.         send(connfd,"1",MAXLINE,0);
  131.     }
  132.    }
  134.    if (strcmp("put",token)==0)  {
  135.     char port[MAXLINE],buffer[MAXLINE],char_num_blks[MAXLINE],char_num_last_blk[MAXLINE],check[MAXLINE];
  136.     int datasock,num_blks,num_last_blk,i;
  137.     FILE *fp;
  138.     token=strtok(NULL," \n");
  139.     cout<<"Filename given is: "<<token<<endl;
  140.     data_port=data_port+1;
  141.     if(data_port==atoi(argv[1])){
  142.         data_port=data_port+1;
  143.     }
  144.     sprintf(port,"%d",data_port);
  145.     datasock=create_socket(data_port);                //creating socket for data connection
  146.     send(connfd, port,MAXLINE,0);                    //sending data connection port to client
  147.     datasock=accept_conn(datasock);                    //accepting connection
  148.     recv(connfd,check,MAXLINE,0);
  149.     cout<<check;
  150.     if(strcmp("1",check)==0){
  151.         if((fp=fopen(token,"w"))==NULL)
  152.             cout<<"Error in creating file\n";
  153.         else
  154.         {
  155.             recv(connfd, char_num_blks, MAXLINE,0);
  156.             num_blks=atoi(char_num_blks);
  157.             for(i= 0; i < num_blks; i++) { 
  158.                 recv(datasock, buffer, MAXLINE,0);
  159.                 fwrite(buffer,sizeof(char),MAXLINE,fp);
  160.                 //cout<<buffer<<endl;
  161.             }
  162.             recv(connfd, char_num_last_blk, MAXLINE,0);
  163.             num_last_blk=atoi(char_num_last_blk);
  164.             if (num_last_blk > 0) { 
  165.                 recv(datasock, buffer, MAXLINE,0);
  166.                 fwrite(buffer,sizeof(char),num_last_blk,fp);
  167.                 //cout<<buffer<<endl;
  168.             }
  169.             fclose(fp);
  170.             cout<<"File download done.\n";
  171.         }
  172.     }
  173.    }
  175.    if (strcmp("get",token)==0)  {
  176.     char port[MAXLINE],buffer[MAXLINE],char_num_blks[MAXLINE],char_num_last_blk[MAXLINE];
  177.     int datasock,lSize,num_blks,num_last_blk,i;
  178.     FILE *fp;
  179.     token=strtok(NULL," \n");
  180.     cout<<"Filename given is: "<<token<<endl;
  181.     data_port=data_port+1;
  182.     if(data_port==atoi(argv[1])){
  183.         data_port=data_port+1;
  184.     }
  185.     sprintf(port,"%d",data_port);
  186.     datasock=create_socket(data_port);                //creating socket for data connection
  187.     send(connfd, port,MAXLINE,0);                    //sending port no. to client
  188.     datasock=accept_conn(datasock);                    //accepting connnection by client
  189.     if ((fp=fopen(token,"r"))!=NULL)
  190.     {
  191.         //size of file
  192.         send(connfd,"1",MAXLINE,0);
  193.         fseek (fp , 0 , SEEK_END);
  194.         lSize = ftell (fp);
  195.         rewind (fp);
  196.         num_blks = lSize/MAXLINE;
  197.         num_last_blk = lSize%MAXLINE; 
  198.         sprintf(char_num_blks,"%d",num_blks);
  199.         send(connfd, char_num_blks, MAXLINE, 0);
  200.         //cout<<num_blks<<"    "<<num_last_blk<<endl;
  202.         for(i= 0; i < num_blks; i++) { 
  203.             fread (buffer,sizeof(char),MAXLINE,fp);
  204.             send(datasock, buffer, MAXLINE, 0);
  205.             //cout<<buffer<<"    "<<i<<endl;
  206.         }
  207.         sprintf(char_num_last_blk,"%d",num_last_blk);
  208.         send(connfd, char_num_last_blk, MAXLINE, 0);
  209.         if (num_last_blk > 0) { 
  210.             fread (buffer,sizeof(char),num_last_blk,fp);
  211.             send(datasock, buffer, MAXLINE, 0);
  212.             //cout<<buffer<<endl;
  213.         }
  214.         fclose(fp);
  215.         cout<<"File upload done.\n";
  217.     }
  218.     else{
  219.         send(connfd,"0",MAXLINE,0);
  220.     }
  221.    }
  223.   }
  225.   if (n < 0)
  226.    cout<<"Read error"<<endl;
  228.   exit(0);
  229.  }
  230.  //close socket of the server
  231.  close(connfd);
  232. }
  233. }
  235. int create_socket(int port)
  236. {
  237. int listenfd;
  238. struct sockaddr_in dataservaddr;
  241. //Create a socket for the soclet
  242. //If sockfd<0 there was an error in the creation of the socket
  243. if ((listenfd = socket (AF_INET, SOCK_STREAM, 0)) <0) {
  244. cerr<<"Problem in creating the data socket"<<endl;
  245. exit(2);
  246. }
  249. //preparation of the socket address
  250. dataservaddr.sin_family = AF_INET;
  251. dataservaddr.sin_addr.s_addr = htonl(INADDR_ANY);
  252. dataservaddr.sin_port = htons(port);
  254. if ((bind (listenfd, (struct sockaddr *) &dataservaddr, sizeof(dataservaddr))) <0) {
  255. cerr<<"Problem in binding the data socket"<<endl;
  256. exit(2);
  257. }
  259.  //listen to the socket by creating a connection queue, then wait for clients
  260.  listen (listenfd, 1);
  262. return(listenfd);
  263. }
  265. int accept_conn(int sock)
  266. {
  267. int dataconnfd;
  268. socklen_t dataclilen;
  269. struct sockaddr_in datacliaddr;
  271. dataclilen = sizeof(datacliaddr);
  272.   //accept a connection
  273. if ((dataconnfd = accept (sock, (struct sockaddr *) &datacliaddr, &dataclilen)) <0) {
  274. cerr<<"Problem in accepting the data socket"<<endl;
  275. exit(2);
  276. }
  278. return(dataconnfd);
  279. }

客户端

客户端代码 client.cpp

  1. #include <iostream>
  2. #include <stdlib.h>
  3. #include <stdio.h>
  4. #include <sys/types.h>
  5. #include <sys/socket.h>
  6. #include <netinet/in.h>
  7. #include <fstream>
  8. #include <string.h>
  9. #include <arpa/inet.h>
  10. using namespace std;
  12. int create_socket(int,char *);
  14. #ifdef WINDOWS
  15.     #include <direct.h>
  16.     #define GetCurrentDir _getcwd
  17. #else
  18.     #include <unistd.h>
  19.     #define GetCurrentDir getcwd
  20.  #endif
  22. #define MAXLINE 4096 /*max text line length*/
  24. int
  25. main(int argc, char **argv)
  26. {
  27.  int sockfd;
  28.  struct sockaddr_in servaddr;
  29.  char sendline[MAXLINE], recvline[MAXLINE];
  31.  //basic check of the arguments
  32.  //additional checks can be inserted
  33.  if (argc !=3) {
  34.   cerr<<"Usage: ./a.out <IP address of the server> <port number>"<<endl;
  35.   exit(1);
  36.  }
  38.  //Create a socket for the client
  39.  //If sockfd<0 there was an error in the creation of the socket
  40.  if ((sockfd = socket (AF_INET, SOCK_STREAM, 0)) <0) {
  41.   cerr<<"Problem in creating the socket"<<endl;
  42.   exit(2);
  43.  }
  45.  //Creation of the socket
  46.  memset(&servaddr, 0, sizeof(servaddr));
  47.  servaddr.sin_family = AF_INET;
  48.  servaddr.sin_addr.s_addr= inet_addr(argv[1]);
  49.  servaddr.sin_port =  htons(atoi(argv[2])); //convert to big-endian order
  51.  //Connection of the client to the socket
  52.  if (connect(sockfd, (struct sockaddr *) &servaddr, sizeof(servaddr))<0) {
  53.   cerr<<"Problem in connecting to the server"<<endl;
  54.   exit(3);
  55.  }
  57.  cout<<"ftp>";
  59.  while (fgets(sendline, MAXLINE, stdin) != NULL) {
  61.   send(sockfd, sendline, MAXLINE, 0);
  62.   char *token,*dummy;
  63.   dummy=sendline;
  64.   token=strtok(dummy," ");
  66.    if (strcmp("quit\n",sendline)==0)  {
  67.        //close(sockfd);
  68.     return 0;
  69.    }
  71.    else if (strcmp("ls\n",sendline)==0)  {
  72.        char buff[MAXLINE],check[MAXLINE]="1",port[MAXLINE];
  73.     int data_port,datasock;
  74.     recv(sockfd, port, MAXLINE,0);                //reciening data connection port
  75.     data_port=atoi(port);
  76.     datasock=create_socket(data_port,argv[1]);
  77.     while(strcmp("1",check)==0){                 //to indicate that more blocks are coming
  78.         recv(datasock,check,MAXLINE,0);
  79.         if(strcmp("0",check)==0)            //no more blocks of data
  80.         break;
  81.         recv(datasock, buff, MAXLINE,0);
  82.         cout<<buff;
  83.     }
  85.    }
  87.    else if (strcmp("!ls\n",sendline)==0)  {
  88.        system("ls");
  89.         cout<<"\n";
  90.    }
  92.    else if (strcmp("pwd\n",sendline)==0)  {
  93.        char curr_dir[MAXLINE];
  94.     recv(sockfd, curr_dir, MAXLINE,0);
  95.     cout<<curr_dir<<endl;
  96.    }
  98.    else if (strcmp("!pwd\n",sendline)==0)  {
  99.        system("pwd");
  100.    }
  102.    else if (strcmp("cd",token)==0)  {
  103.     char check[MAXLINE];
  104.     token=strtok(NULL," \n");
  105.     cout<<"Path given is: "<<token<<endl;
  106.     recv(sockfd,check,MAXLINE,0);
  107.     if(strcmp("0",check)==0){
  108.         cerr<<"Directory doesn't exist. Check Path"<<endl;
  109.     }
  111.    }
  113.    else if (strcmp("!cd",token)==0)  {
  114.     token=strtok(NULL," \n");
  115.     cout<<"Path given is: "<<token<<endl;
  116.     if(chdir(token)<0){
  117.         cerr<<"Directory doesn't exist. Check path"<<endl;
  118.     }
  119.    }
  121.    else if (strcmp("put",token)==0)  {
  122.        char port[MAXLINE], buffer[MAXLINE],char_num_blks[MAXLINE],char_num_last_blk[MAXLINE];
  123.     int data_port,datasock,lSize,num_blks,num_last_blk,i;
  124.     FILE *fp;
  125.     recv(sockfd, port, MAXLINE,0);                //receiving the data port
  126.     data_port=atoi(port);
  127.     datasock=create_socket(data_port,argv[1]);
  128.     token=strtok(NULL," \n");
  129.     if ((fp=fopen(token,"r"))!=NULL)
  130.     {
  131.         //size of file
  132.         send(sockfd,"1",MAXLINE,0);
  133.         fseek (fp , 0 , SEEK_END);
  134.         lSize = ftell (fp);
  135.         rewind (fp);
  136.         num_blks = lSize/MAXLINE;
  137.         num_last_blk = lSize%MAXLINE; 
  138.         sprintf(char_num_blks,"%d",num_blks);
  139.         send(sockfd, char_num_blks, MAXLINE, 0);
  140.         //cout<<num_blks<<"    "<<num_last_blk<<endl;
  142.         for(i= 0; i < num_blks; i++) { 
  143.             fread (buffer,sizeof(char),MAXLINE,fp);
  144.             send(datasock, buffer, MAXLINE, 0);
  145.             //cout<<buffer<<"    "<<i<<endl;
  146.         }
  147.         sprintf(char_num_last_blk,"%d",num_last_blk);
  148.         send(sockfd, char_num_last_blk, MAXLINE, 0);
  149.         if (num_last_blk > 0) { 
  150.             fread (buffer,sizeof(char),num_last_blk,fp);
  151.             send(datasock, buffer, MAXLINE, 0);
  152.             //cout<<buffer<<endl;
  153.         }
  154.         fclose(fp);
  155.         cout<<"File upload done.\n";
  156.     }
  157.     else{
  158.         send(sockfd,"0",MAXLINE,0);
  159.         cerr<<"Error in opening file. Check filename\nUsage: put filename"<<endl;
  160.     }
  161.    }
  163.    else if (strcmp("get",token)==0)  {
  164.        char port[MAXLINE], buffer[MAXLINE],char_num_blks[MAXLINE],char_num_last_blk[MAXLINE],message[MAXLINE];
  165.     int data_port,datasock,lSize,num_blks,num_last_blk,i;
  166.     FILE *fp;
  167.     recv(sockfd, port, MAXLINE,0);
  168.     data_port=atoi(port);
  169.     datasock=create_socket(data_port,argv[1]);
  170.     token=strtok(NULL," \n");
  171.     recv(sockfd,message,MAXLINE,0);
  172.     if(strcmp("1",message)==0){
  173.         if((fp=fopen(token,"w"))==NULL)
  174.             cout<<"Error in creating file\n";
  175.         else
  176.         {
  177.             recv(sockfd, char_num_blks, MAXLINE,0);
  178.             num_blks=atoi(char_num_blks);
  179.             for(i= 0; i < num_blks; i++) { 
  180.                 recv(datasock, buffer, MAXLINE,0);
  181.                 fwrite(buffer,sizeof(char),MAXLINE,fp);
  182.                 //cout<<buffer<<endl;
  183.             }
  184.             recv(sockfd, char_num_last_blk, MAXLINE,0);
  185.             num_last_blk=atoi(char_num_last_blk);
  186.             if (num_last_blk > 0) { 
  187.                 recv(datasock, buffer, MAXLINE,0);
  188.                 fwrite(buffer,sizeof(char),num_last_blk,fp);
  189.                 //cout<<buffer<<endl;
  190.             }
  191.             fclose(fp);
  192.             cout<<"File download done."<<endl;
  193.         }
  194.     }
  195.     else{
  196.         cerr<<"Error in opening file. Check filename\nUsage: put filename"<<endl;
  197.     }
  198.    }
  199.    else{
  200.     cerr<<"Error in command. Check Command"<<endl;
  201.    }
  202.    cout<<"ftp>";
  204.  }
  206.  exit(0);
  207. }
  210. int create_socket(int port,char *addr)
  211. {
  212.  int sockfd;
  213.  struct sockaddr_in servaddr;
  216.  //Create a socket for the client
  217.  //If sockfd<0 there was an error in the creation of the socket
  218.  if ((sockfd = socket (AF_INET, SOCK_STREAM, 0)) <0) {
  219.   cerr<<"Problem in creating the socket"<<endl;
  220.   exit(2);
  221.  }
  223.  //Creation of the socket
  224.  memset(&servaddr, 0, sizeof(servaddr));
  225.  servaddr.sin_family = AF_INET;
  226.  servaddr.sin_addr.s_addr= inet_addr(addr);
  227.  servaddr.sin_port =  htons(port); //convert to big-endian order
  229.  //Connection of the client to the socket
  230.  if (connect(sockfd, (struct sockaddr *) &servaddr, sizeof(servaddr))<0) {
  231.   cerr<<"Problem in creating data channel"<<endl;
  232.   exit(3);
  233.  }
  235. return(sockfd);
  236. }