Copy one line of text from a file to a string in c++

Question

I need to copy one line of text from a text file in c++, I have a program to find the line inwhich a word resides, so I decided if I could just take each individual line and load it into a string I could search line by line, string by string to find the correct word and its position (in characters, not lines) in the file. Help would be greatly appreciated.

edit: I found the code I am using to locate the line

#include <cstdlib> 
#include <iostream>
#include <string>
#include <fstream>
#include <cstring>
#include <conio.h>

using namespace std;

int main()
{   

    ifstream in_stream;           //declaring the file input
    string filein, search, str, replace; //declaring strings
    int lines = 0, characters = 0, words = 0; //declaring integers
    char ch;

    cout << "Enter the name of the file\n";   //Tells user to input a file name
    cin >> filein;                            //User inputs incoming file name
    in_stream.open (filein.c_str(), ios::in | ios::binary); //Opens the file


    //FIND WORDS
    cout << "Enter word to search: " <<endl;
    cin >> search; //User inputs word they want to search

    while (!in_stream.eof())  
    {
        getline(in_stream, str); 
        lines++;                
        if ((str.find(search, 0)) != string::npos) 
        {
            cout << "found at line " << lines << endl;
        }
    }

    in_stream.seekg (0, ios::beg);  // the seek goes here to reset the pointer....

    in_stream.seekg (0, ios::beg);  // the seek goes here to reset the pointer.....
    //COUNT CHARACTERS

    while (!in_stream.eof())      
    {
        in_stream.get(ch);    
        cout << ch;
        characters ++;      
    }
    //COUNT WORDS

    in_stream.close ();               


    system("PAUSE");                     
    return EXIT_SUCCESS;    
}

Answer 1

You only need one loop to accomplish this. Your loop should look something like this:

while (getline(in_stream, str))
{
    lines++;
    size_t pos = str.find(search, 0);
    if (pos != string::npos) 
    {
        size_t position = characters + pos;
        cout << "found at line " << lines << " and character " << position << endl;
    }
    characters += str.length();
}

I also recommend you don't mix int and size_t types. For example, characters should be declared as size_t, not int.