reading an array of indefinite length from file

[dreambox]

Hi, I want to read a bunch of two-digit numbers from a file and put them into an array, without any specifications about how many I'm supposed to read. Is there any way to read them so the reading stops at the end of the file?

[savavampir]

You can use standard container for this:

std::vector<int> v;
std::ifstream in;
in.open("digits.txt");
if(!in.fail())
{
    while(!in.eof())
    {
        int num;
        std::string line;
        ...//read line and convert into int
        v.push_back(num);
    }
}
in.close();

[dreambox]

Thanks for the reply but I have no idea what that is... I think I should have mentioned that the only way I know to read from files looks like this (I'm a high school student with no extra experience in programming):

int n;
ifstream f("data.in");
ofstream g("data.out");
f>>n;

[savavampir]

Here is more complete code, there might be better ways to do it, since i am beginner too i might overlooked it:

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

int main()
{
	std::vector<int> v;// create vector that can hold int's
	std::ifstream in;
	in.open("digits.txt");//open digits.txt
	if(!in.fail())//test if opened
	{
		while(!in.eof())//while not end of file
		{
			int num;
			std::string line;
			in >> line;//read into string
			num = atoi(line.c_str());//konvert string of chars into int
			v.push_back(num);//add value into vector
		}
	}
	in.close();//close file after done

        //print contet of vector/array
	for(unsigned int i = 0; i < v.size(); ++i)
	{
		std::cout << "v[" << i << "] = " << v[i] << std::endl;
	}

	std::cout << "Press enter to exit...";
	std::cin.get();
	return 0;
}

where digits.txt is something like:

22
51
7
23
78
455
75
46

[dreambox]

I think I get it now...so the idea is to read them as characters, see if they're different from the end-of-file character, and then convert to numbers? Any idea on how the end-of-file character is noted if I want to write line 13 like

while(x!=end-of-file)

where x is a number that I've read?

[savavampir]

I didn't understood you well. Do you want to stop reading if 'x' is some arbitary value (that you've choosen)?
Say:
digits.txt

22
33
4
78
666
12
47

let say you want to stop where x is 666

then:

if(!in.fail())//test if opened
	{
		while(!in.eof())//read until end of file
		{
			int num;
			std::string line;
			in >> line;//read into string
			num = atoi(line.c_str());//konvert string of chars into int
                        if(num == 666)//if it is 666
                               break;//quit reading
			v.push_back(num);//add value into vector
		}
	}

[dreambox]

No, I want to stop reading if 'x' is the end of file character.
Kinda like:

char x;
int i,v[100];
ifstream f("data.in");
f>>x;
i=1;
while (x!=end of file)
   {v[i]=x;//assuming that we convert x to int
     i++;
     f>>x;}

My question was, does the end of file character have an ASCII code or something so I could put it in the 'while' condition?

[zwA4jE8b]

No, it is not an ascii char.

like sava said, !in.eof() means not End Of File.

eof (often returned as -1) does not have a special character. The stream sets the eof bit. so yo cannot test if a character is the eof.

http://en.wikipedia.org/wiki/End-of-file

and is unequal to any valid character code.

[dreambox]

Ok, thanks a lot guys, I'll manage now.