NEED HELP!!! cstring

[wandou99]

Can anyone help me to write a simple sample code about to read the file line by line and store it into cstring? The file contains few rows of sentences.THANK YOU!

[nuderobmonkey]

Why do you want to use cstrings, is there a distinct reason for doing that?

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

int main()
{
    std::vector<char*> text; // for holding all text lines
    
    std::ifstream ifs( "myTextFile.txt");
    if(!ifs) {
        std::cerr << "Text-file couldn't opened!\n";
        return 1;
    }
    // We reading a whole line to an std::string and then we copy
    // each character into a c-string
    while (true) {
        std::string line;
        std::getline( ifs, line);
        if (!ifs) break; // Input file is at end or an error happened.
        char * tmp = new char[line.length()+1];
        for (int i = 0; i < line.length(); ++i)
        {
            tmp[i] = line[i];
        }
        tmp[line.length()] = '\0';
        text.push_back( tmp);
    }
    
    // for testing:
    for( char* & line : text) { std::cout << line << '\n'; }
    
    // free memory on heap:
    for ( char* & line : text) { delete line; }
}
/*
// The same program without using c-strings:
int main()
{
    std::vector<std::string> text; // this container holds all lines.
    std::ifstream ifs( "myTextFile.txt");
    if(!ifs) { std::cerr << "Text file couldn't opened!\n"; return 1; }

    std::string line;
    while ( std::getline( ifs, line)) {
        text.push_back( line );
    }
    // for testing:
    for (auto & line : text) std::cout << line << '\n';
    
    // We don't need to free any memory from heap manually.
}
*/

[wandou99]

I think yes because my problem is like I need to read every sentence in textfile using getline.
Go through every character in the sentence....something like that. The code I wrote will store all the characters in every sentences into the cstring...i can't solve it

[nuderobmonkey]

Could you expose what you want to do concretely? - And perhaps posting your code (or a relevant part of)?

[Duthomhas]

This is clearly a homework assignment, and OP is asking us to do it for him.

@wandou99
Do you not have course notes or anything? Do you have specific constraints in this assignment. You have only given one very general piece of information: “The file contains a few rows of sentences.” How many is “a few”? Three? Five? Less than fifteen?

Are you storing every line in a different C-string? Or can you reuse one C-string over and over? Surely you aren’t referring to Embarcadero’s CString class, but to char* strings, right?

Is this supposed to be using C++? Or C? Because the way you do it is significantly different between the two, with different extra care needed when you have got it.

If all you want is an example, there are plenty that can be found on the internet. Here is one of the first to pop up on Googling things like "C file IO example":
https://www.tutorialspoint.com/cprogramming/c_file_io.htm