No of lies in a text file.

[meatstu]

Hello everyone I was hoping someone could point me in the right direction with a problem I have reading from a text file.
I am trying to find out how many lines of data are in a text file,the file will contain a list of names in this sort of format:
john
dave
bob
etc.
I have written the following code so far:

filesize=0;
fstream file1;					
file1.open("graph.txt",ios::in);
{
	while(!file1.eof())
	{
		filesize++;
	}
		
}
file1.close();

The program runs and gets stuck in the while loop, Is this due to the fact nothing is being done with the data in the file whilst in the loop?
I dont want to read the data (names) in from file untill I know how many lines are in there.
Anybody got any tips?
cheers
Stu.

[horace1]

it gets stuck in the while loop because you never read from the file so it never reaches EOF. You need to read the text, e.g. use getline() in <string>

http://www.cppreference.com/cppstring/getline.html

[meatstu]

Ok, I think I follow.
I'll have to go through it slowly.
Thanks

[meatstu]

Sorry I am still having no luck, I have tried this:

filesize=0;
fstream file1;					
string s;
file1.open("graph.txt",ios::in);
{
	while(!file1.eof())
	{
		getline(cin,s);
		filesize++;
	}
		
}
file1.close();

Is this wrong? I am getting undeclared identifier erros for s,string and getline.
I have #include <string.h>
I'm stumped!

[DeMan]

I think String has a capital S (but that could be a lie )

[sicarie]

I think String has a capital S (but that could be a lie )

Wrong language, DeMan - you're thinking Java!

[sicarie]

Sorry I am still having no luck, I have tried this:

filesize=0;
fstream file1;					
string s;
file1.open("graph.txt",ios::in);
{
	while(!file1.eof())
	{
		getline(cin,s);
		filesize++;
	}
		
}
file1.close();

Is this wrong? I am getting undeclared identifier erros for s,string and getline.
I have #include <string.h>
I'm stumped!

try removing the .h (is this in C or C++?)

[meatstu]

It's C++, It's in a method within a class.
I am using MS Visual C++ 6.0.
This is all pretty new to me.

[sicarie]

It's C++, It's in a method within a class.
I am using MS Visual C++ 6.0.
This is all pretty new to me.

Yeah, get rid of the '.h'. C libs have those - C++ no longer uses them. (though some use #include "library.h" - generally if it's in quotes (to my experience), it will be a .h)

[meatstu]

Yeah it compiles ok now but it's still getting stuck in my while loop!

[sicarie]

meatstu-

Just out of curiousity, why do you have the '{'s under the file1.open(.... line?

filesize=0;
fstream file1;					
string s;
file1.open("graph.txt",ios::in);
{
	while(!file1.eof())
	{
		getline(cin,s);
		filesize++;
	}
		
}
file1.close();

[sicarie]

meatstu-

Just out of curiousity, why do you have the '{'s under the file1.open(.... line?

filesize=0;
fstream file1;					
string s;
file1.open("graph.txt",ios::in);
{
	while(!file1.eof())
	{
		getline(cin,s);
		filesize++;
	}
		
}
file1.close();

It has to do with your getline(). You want to read from the file - but you are getline'ing from "cin".

[meatstu]

I dont quite follow, if you mean why do I put my '{' under the line rather than than at the end of the file1.open line, this was the style I was first shown when I first started learning programming.

[sicarie]

I dont quite follow, if you mean why do I put my '{' under the line rather than than at the end of the file1.open line, this was the style I was first shown when I first started learning programming.

file1.open("graph.txt",ios::in);
{
	while(!file1.eof())
	{
		getline(cin,s);
		filesize++;
	}
		
}

The brackets - not the ones for the while loop, but under the file1.open line. That's not a loop, it's just a statement - there's no need for those.

[meatstu]

Ah right thats the way I've done file read in the past, I was told to put the brackets there.
It's not getting stuck in the loop now, I've changed 'cin' to 'file1'. However it now seems to be corrupting the data in the file.
I will try and work throught his myself, but many thanks for your help, it's much appreciated.
Stu.