Simple fp_in question.

[BluePudding]

Hello everyone!
This is my first post here and I have to say that I am very glad to have found this website.

My problem, however simple it may seem to you, has baffled me for a week now, and I have scoured the Internet for an answer to no avail. I just started seriously programming things that my friends and I find useful, and have hit a road block in my latest project.

The program is supposed to read a notepad file, line by line, and use those lines to perform an action. It's sort of an attempt to make a very simplified language for them to be able to give it some simple instructions.

I hit my difficulties when I actually try to split up the notepad file. My problem is the fact that I have no idea how =P. I want to check each line of the .txt file one by one, and assign each of those to it's own string. Here's what I have so far (this only reads the first line)

I've posted only the code relevent to my question, this only prints the line on screen.

{
    GetFileName();
    ifstream fp_in;  
    ofstream fp_out;
    fp_in.open(filename, ios::in);   
    fp_in >> mystring;
    cout << "First line is as follows: ";
    cout <<  mystring;
    fp_in.close();  
    cin.get();
}

So my question is simple, how can I modify this to read other lines of that same file?

Many many thanks to those who read or help!

[Desolation]

std::string tmp;
while(std::getline(fp_in, tmp, '\n')) {
  // process tmp
}

[BluePudding]

Thanks a lot for your response, but I am sort of confused here... how do I put that in my code and where do I put the line that it's reading? I should've probably explained that I need it to be able to go to any line at any given time.

Thanks again.
(did I meantion that I'm still pretty... eh... stupid? O.o)

[SlyMaelstrom]

I should've probably explained that I need it to be able to go to any line at any given time.

This is simple enough. Just store each line into an array or a vector. Make sure you use a '\n' as a delimeter in getline() as that will be the end of each line.

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

int main() {
   std::ifstream inFile("myInstructions.txt");
   std::vector<std::string> instructions;
   
   while(inFile) {
      instructions.push_back(*(new std::string));
      std::getline(inFile, instructions[instructions.size()-1], '\n');
   }
   
   std::cout << "Here are the instructions:\n";
   for(std::vector<std::string>::iterator i = instructions.begin(); 
                                          i < instructions.end(); i++) {
      std::cout << *i << '\n';
   }
   
   std::cin.get();
   
   return 0;
}

/* Output:
Here are the instructions:
Do homework.
Go to sleep.
Wake up.
Take shower.
Get dressed.
Eat breakfast.
Go to school.

*/

[jafet]

You said you "scoured the Internet". A quick scouring should have revealed everything you needed.

cppreference.com
cprogramming.com/tutorial
faq.cprogramming.com
And many more...


By the way, getline() delimits on '\n' by default.

[SlyMaelstrom]

By the way, getline() delimits on '\n' by default.

That doesn't stop him from trying another character instead.