My output file does not read the spaces from my input file.

I am having trouble getting my program to read the spaces in my input file, I am new to and objects in general so any help would be appreciated.

My input file is: Hello my name is Pierre. I like to code .

My output file is: HellomynameisPierre.Iliketocode.

Another question I have is how can I check if my string has more than one space, and if it does, replace it with only one space.

#include <fstream>
#include <iostream>
#include <cstdlib>

using namespace std;

void clean_file(ifstream& fin, ofstream& fout);

int main()
{
    ifstream fin;
    ofstream fout;
    clean_file(fin, fout);
}

void clean_file(ifstream& fin, ofstream& fout)
{
    fin.open("string.txt");
    if (fin.fail())
    {
        cout << "File could not open.";
        exit(1);
    }
    fout.open("cleanString.txt");
    if (fout.fail())
    {
        cout << "File could not open.";
        exit(1);
    }
    char line;
    while (fin >> line)
    {
        fout << line;
    }


    fin.close();
    fout.close();
}