FTP Server and Client Implementation in C/C++ Revision as of 22:07, 13 December 2013 by Arjun Suresh (talk | contribs) (diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)

<syntaxhighlight lang="C">

/*FTP server*/

1. include <sys/socket.h>
2. include <netinet/in.h>
3. include <string.h>
4. include <stdio.h>
5. include <stdlib.h>
6. include<sys/stat.h>/*for getting file size using stat()*/
7. include<sys/sendfile.h>//for sendfile()
8. include<fcntl.h>//for O_RDONLY..

int main(int argc,char *argv[]) {

 struct sockaddr_in server,client;
 struct stat obj;
 int sock1,sock2;
 char buf[100],command[5],filename[20];
 int k,i,size,len,c;
 int filehandle;
 sock1 = socket(AF_INET,SOCK_STREAM,0);
 if(sock1==-1)
   {
     printf("Socket creation failed");
     exit(1);
   }
 server.sin_port = atoi(argv[1]);
 server.sin_addr.s_addr = 0;
 k = bind(sock1,(struct sockaddr*)&server,sizeof(server));
 if(k==-1)
   {
     printf("Binding error");
     exit(1);
   }
 k=listen(sock1,1);
 if(k==-1)
   {
     printf("Listen failed");
     exit(1);
   }
 len = sizeof(client);
 sock2 = accept(sock1,(struct sockaddr*)&client,&len);
 i = 1;
 while(1)
   {
     recv(sock2,buf,100,0);
     sscanf(buf,"%s",command);
     if(!strcmp(command,"ls"))

{ system("ls >temps.txt"); i = 0; stat("temps.txt",&obj); size = obj.st_size; send(sock2,&size,sizeof(int),0); filehandle = open("temps.txt",O_RDONLY); sendfile(sock2,filehandle,NULL,size); }

     else if(!strcmp(command,"get"))

{ sscanf(buf,"%s%s",filename,filename); stat(filename,&obj); filehandle = open(filename,O_RDONLY); size = obj.st_size; if(filehandle==-1) size = 0; send(sock2,&size,sizeof(int),0); if(size) sendfile(sock2,filehandle,NULL,size);

}

     else if(!strcmp(command,"put"))
       {

int c=0,len; char * f; sscanf(buf+strlen(command),"%s",filename); recv(sock2,&size,sizeof(int),0); i = 1; while(1) { filehandle = open(filename,O_CREAT|O_EXCL|O_WRONLY,0666); if(filehandle == -1) { sprintf(filename+strlen(filename),"%d",i); } else break; } f = malloc(size); recv(sock2,f,size,0); c = write(filehandle,f,size); close(filehandle); send(sock2,&c,sizeof(int),0);

       }
     else if(!strcmp(command,"pwd"))

{ system("pwd>temp.txt"); i = 0;

         FILE*f = fopen("temp.txt","r");
         while(!feof(f))
           buf[i++] = fgetc(f);
         buf[i-1] = '\0';

fclose(f);

         send(sock2,buf,100,0);

}

     else if(!strcmp(command,"cd"))
       {
         if(chdir(buf+3) == 0)

c = 1; else c = 0;

         send(sock2,&c,sizeof(int),0);
       }

     else if(!strcmp(command,"bye")||!strcmp(command,"quit"))

{ printf("FTP server quitting..\n"); i = 1; send(sock2,&i,sizeof(int),0); exit(0); }

   }
 return 0;

}

/*FTP Client*/

1. include <sys/socket.h>
2. include <netinet/in.h>
3. include <string.h>
4. include <stdio.h>
5. include <stdlib.h>
6. include<sys/stat.h>//for getting file size using stat()
7. include<sys/sendfile.h>//for sendfile()
8. include<fcntl.h>//for O_RDONLY..

int main(int argc,char *argv[]) {

 struct sockaddr_in server;
 struct stat obj;
 int sock;
 int choice;
 char buf[100],command[5],filename[20],*f;
 int k,size,status;
 int filehandle;
 sock = socket(AF_INET,SOCK_STREAM,0);
 if(sock==-1)
   {
     printf("socket creation failed");
     exit(1);
   }
 server.sin_family = AF_INET;
 server.sin_port = atoi(argv[1]);
 server.sin_addr.s_addr = 0;
 k = connect(sock,(struct sockaddr*)&server,sizeof(server));
 if(k==-1)
   {
     printf("Connect Error");
     exit(1);
   }
 int i = 1;
 while(1)
   {
     printf("Enter a choice:\n1- get\n2- put\n3- pwd\n4- ls\n5- cd\n6- quit\n");
     scanf("%d",&choice);
     switch(choice)

{ case 1: printf("Enter filename to get: "); scanf("%s",filename); strcpy(buf,"get "); strcat(buf,filename); send(sock,buf,100,0); recv(sock,&size,sizeof(int),0); if(!size) { printf("No such file on the remote directory\n\n"); break; } f = malloc(size); recv(sock,f,size,0); while(1) { filehandle = open(filename,O_CREAT|O_EXCL|O_WRONLY,0666); if(filehandle == -1) { sprintf(filename+strlen(filename),"%d",i);//needed only if same directory is used for both server and client } else break; } write(filehandle,f,size,0); close(filehandle); strcpy(buf,"cat "); strcat(buf,filename); system(buf); break; case 2: printf("Enter filename to put to server: ");

         scanf("%s",filename);

filehandle = open(filename,O_RDONLY);

         if(filehandle == -1)
           {
             printf("No such file on the local directory\n\n");
             break;
           }
         strcpy(buf,"put ");

strcat(buf,filename); send(sock,buf,100,0); stat(filename,&obj); size = obj.st_size; send(sock,&size,sizeof(int),0); sendfile(sock,filehandle,NULL,size); recv(sock,&status,sizeof(int),0); if(status) printf("File stored successfully\n"); else printf("File failed to be stored to remote machine\n"); break; case 3: strcpy(buf,"pwd"); send(sock,buf,100,0); recv(sock,buf,100,0); printf("The path of the remote directory is: %s\n",buf); break; case 4: strcpy(buf,"ls");

         send(sock,buf,100,0);

recv(sock,&size,sizeof(int),0);

         f = malloc(size);
         recv(sock,f,size,0);

filehandle = creat("temp.txt",O_WRONLY); write(filehandle,f,size,0); close(filehandle);

         printf("The remote directory listing is as follows:\n");

system("cat temp.txt"); break; case 5: strcpy(buf,"cd "); printf("Enter the path to change the remote directory: "); scanf("%s",buf+3);

         send(sock,buf,100,0);

recv(sock,&status,sizeof(int),0);

         if(status)
           printf("Remote directory successfully changed\n");
         else
           printf("Remote directory failed to change\n");
         break;

case 6: strcpy(buf,"quit");

         send(sock,buf,100,0);
         recv(sock,&status,100,0);

if(status) { printf("Server closed\nQuitting..\n"); exit(0); } printf("Server failed to close connection\n"); }

   }

}

</syntaxhighlight>

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