Changable filename based on user input

[wasing]

Good Morning

small question and thanks for your time

im trying to write a portion of this program so that the user can input the

name of a specific goal and then it creates a text file with that name.

however for 2 days of trying to find my answer all i can find for this is it

must be a constant char. can anyone point me in a direction of how make a file

whose name doesn't have to be constant

#include <iostream>
#include <fstream>
#include <string>

using namespace std;

int main()
{
    ofstream myfile;
    // Allow User to Input Name of Goal
    string goal_name, specific, measurable, attainable, realistic, special_day;
    short int year;
    char month, day;
    cout <<"please input a goal name"<<endl;
    getline (cin, goal_name);
    // Names the file after the goal name
    // *yes that is a failed attempt to make this work*
    myfile.open ("<<goal_name<<.txt");

thanks for your time,

wasing

[Duthomhas]

So easy you'll be amazed.

#include <fstream>
#include <iostream>
#include <string>
using namespace std;

int main()
  {
  ofstream f;
  string filename;

  cout << "Please enter a file name to write: ";
  getline( cin, filename );

  f.open( filename.c_str() );
  f << "Hello world!\n";
  f.close();

  cout << "Good job! 'type' or 'cat' your new file to see what it says.\n";
  return 0;
  }

Hope this help.s

[wasing]

wow thanks a million Duoas

is this referenced anywhere on this site because i would not have found that on my own.

anyway thanks again

[daveD]

Hi,


The problem is that a string type is being used here.

If I am not mistaken, the string type does not have a null character at the end and this is what gives you the problem.

Your filename, (goalname), mustn't be passed through as a string. The c_str() function can be used, (you can find a proper explanation to this function on the net).
Otherwise you can change your variable it from a string to a char array.

Hope this helps


daveD

[Duthomhas]

Please do not give bad advice.
Using a std::string and the c_str() member function is exactly the correct thing to do.

[Albatross]

I'd like to add an extension to Duoas' program at line 13, as the OP appeared to wanted to append .txt to the name.
goalname += ".txt";

-Albatross

[wasing]

hey thanks albatross i was wondering that earlier

thanks for all your help guys