How to open file based on user input?

Question

This code keeps giving me errors i dont know what Im doing wrong? How can I request the user to input the filename and then open that file and perform tasks with the data.

Example:

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

using namespace std;

int main ()
{ 
ifstream inData;
ofstream outData;
string fileName;

cout << "Enter the data file Name : " << endl;//asks user to input filename
cin >> fileName; //inputs user input into fileName

inData.open(fileName); //heres where i try to open the file with the users input?
outData.open(fileName);
cout << fileName;
return 0;   
}

The code keeps giving me errors. I have tried to use getline? I want the fileName to be string and not char.

Usually when you say you get errors, it's a good idea to include those errors. You know... just in case our crystal balls aren't in the shop getting repaired. — Nik Bougalis, Mar 26 '13 at 18:51
It might be (and in this case *is*) but including the error you are getting is always a good idea. — Nik Bougalis, Mar 26 '13 at 18:54
@user1725435 You can edit the question to include all the necessary information. — Konstantin Dinev, Mar 27 '13 at 06:26

score 4 · Accepted Answer · answered Mar 26 '13 at 18:48

4

You're passing std::string objects to the parameters, not actual null-terminated char pointers. To do that, use c_str:

inData.open(fileName.c_str());
outData.open(fileName.c_str());

answered Mar 26 '13 at 18:48

0x499602D2

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What does c_str() mean? – user1725435 Mar 26 '13 at 18:51
@user1725435 [Here's the documentation for std::string::c_str](http://en.cppreference.com/w/cpp/string/basic_string/c_str) – 0x499602D2 Mar 26 '13 at 18:52
2

Note: This has been changed for C++11. – Martin York Mar 26 '13 at 18:56

How to open file based on user input?

1 Answers1