Help accepting a file from a user

[DoABarrelRoll94]

How do you accept a .txt file from a user in which you don't what file that person will input? This is what I have so far. I want the user to input the .txt file so I can format it to the rules specified in the assignment I've been given.

#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <cctype>       //for isspace
using namespace std;

int main(int argc, char* argv[])
{
    string fileName;
    string content;
    
    cout << "Enter a file name.\n";
    cin >> fileName;
    
    ifstream fileName;
    
    return 0;
}

[Arslan7041]

The user inputs the name of the txt file, not the name of the ifstream object

#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <cctype>       //for isspace
using namespace std;

int main(int argc, char* argv[])
{
    string fileName;
    string content;
    
    cout << "Enter a file name.\n";
    cin >> fileName;
    
    ifstream infile(filename);
    
    return 0;
}

[DoABarrelRoll94]

Thank you. What does the infile function do? I tried searching for it in the c++ reference tab but couldn't find it. Is it the same as fileName.open?

[Arslan7041]

infile is not a function, its the name of the ifstream object. The code below is equivalent to the one I have in my previous post.

#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <cctype>       //for isspace
using namespace std;

int main(int argc, char* argv[])
{
    string fileName;
    string content;
    
    cout << "Enter a file name.\n";
    cin >> fileName;
    
    ifstream infile;            // declare file
    infile.open(filename); // open file using user-inputted filename
    
    return 0;
}

[liuyang]

Basically if your assignment is not about 'how to read / write file', you don't have to work on the files.

You could just write the program as it reads text from user input, and then use pipe to send the text fie as user input.

For example, after you build your 'myassignment.exe', you could just run it like this:

myassignment.exe < myinput.txt

[DoABarrelRoll94]

Now I'm having trouble copying the text from the file into a string. I'm probably not doing it right.

#include <iostream>
#include <fstream>
#include <string>
#include <queue>
#include <vector>
#include <cctype>
using namespace std;

int main(int argc, char* argv[])
{
    if(argc != 2)
        cout << "usage: " << argv[0] << endl;
    else
    {
        ifstream infile;
        infile.open(argv[1]);
        if(!infile.is_open())
        {
            cerr << "Could not open file\n";
            return -1;
        }
        else
        {
            char x;
            string word;
            while (infile.get(x))
            {
                word << x;
            }
        }
    }
        return 0;
}

Error is on line 32.

[DoABarrelRoll94]

I tried copying to a char array too but I'm having an error on line 32 again.

#include <iostream>
#include <fstream>
#include <string>
#include <queue>
#include <vector>
#include <cctype>
using namespace std;

int main(int argc, char* argv[])
{
    if(argc != 2)
        cout << "usage: " << argv[0] << endl;
    else
    {
        ifstream infile;
        infile.open(argv[1]);
        if(!infile.is_open())
        {
            cerr << "Could not open file\n";
            return -1;
        }
        else
        {
            char array[10000];
            char x;
            while(infile.get(x))
            {
                x >> array;
            }
        }
    }
        return 0;
}

[integralfx]

You should get rid of the headers you aren't using.

http://www.cplusplus.com/doc/tutorial/files/