Question

Im working on a two part program that uses an encoder do encode a text file then a decoder to decode the text file. However i cannot get my decoder to read the whole text file it just reads the first line. How do i fix this, ive played around with the loops but it is not helping me.

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

int main() 
{ 
    ifstream fin;
    ofstream fout;
    string lineFromFile; 
    fin.open("secret.txt");
    if (!fin.good()) throw "I/O error";
    fout.open("secret.txt", ios::app); 
    if (!fout.good()) throw "I/O error"; 

    while (fin.good())
    {
        getline(fin, lineFromFile); 
        for (int i = 0; i < lineFromFile.length(); i++) // for each char in the string...
            lineFromFile[i]--; // bump the ASCII code by 1
        fout << lineFromFile << endl;     
    }//while

    fin.close();
    fout.close();
    return 0;
}

Answer 1

You are closing the stream in the first iteration (i.e., after reading the first line). Then you open the output stream to write the first line. Only then do you reach the end of the while-loop, at which time fin.good() cannot be true anymore since you closed fin.

The loop should contain only the reading and writing. Opening done before the loop, closing done after.

Additional suggestion: Use proper indenting, it helps understanding the control flow.