Why am I unable to open the files?

Please tell me why this is failing to open the files:

Code:

string trainingFile;
	string testingFile;

	cout << "Please specify the file you would like to use for TRAINING: " << endl; 
	cin >> trainingFile;

	cout <<"Please specify the file you would like to use for TESTING: " << endl;   
	cin >> testingFile;

	ifstream file;				     // input file stream
	file.open(trainingFile.c_str()); // c_str() converts file name into a form open() can handle
	if(file.fail())
	{
		cerr << "Input file 'training' problem!" << endl;
		return 1;
	}

	ifstream test_file;
	test_file.open(testingFile.c_str());
	if(test_file.fail())
	{
		cerr << "Input file 'testing' problem!" << endl;
		return 1;
	}

No idea. Try explicit paths. If that works, they it's probably you who enter incorrect implicit paths to the files.

Sorry I don't know what explicit and implicit paths means?

Explicitly means a full path, that is, for Windows, example C:\MyFile.txt.
Implicitly means a relative path, such as MyFile.txt.
I should have used full/relative instead of explicitly/implicitly. Sorry.

Can I open 2 files at the same time? Maybe the first one needs to be closed before I can read in second one?

It works fine if I say:

Code:

	ifstream file("y=x2_positive.csv");
	if(file.fail())
	{
		cerr << "Input file problem!" << endl;
		return 1;
	}

	ifstream test_file("testing_y=x2_positive.csv");
	if(test_file.fail())
	{
		cerr << "Input file problem!" << endl;
		return 1;
	}

But would have liked to specify at runtime....

Originally Posted by Elysia

Explicitly means a full path, that is, for Windows, example C:\MyFile.txt.
Implicitly means a relative path, such as MyFile.txt.
I should have used full/relative instead of explicitly/implicitly. Sorry.

Im too much of a novice so either would have actually been new terminology to me! (I think you mean for me to have done what I posted above?). Thank you

There is no limit on how many files you can have open at once (language wise). 2 should be no problem. The most likely cause is that it cannot find the files you are specifying.
As for full/relative path, the thing is this:
- Every file has a path associated with it. For example: C:\MyDirectory\MyFile.txt. Nothing difficult here. This is a full path.
- Now consider that, say, your executable is already located in C:\MyDirectory. Then, when your program starts, its working directory is C:\MyDirectory. So then you can say MyFile.txt, which is a relative path. This refers to the fact that you don't specify a full path. In this case, your relative path is added to the working directory to form the full path. In this case, it becomes C:\MyDirectory\MyFile.txt.

i think elysia is talking about what i call absolute and relative paths. absolute (explicit) means that you spell out the entire path all the way from the root (e.g., in Windows, c:\Users\...) relative (implicit) allows you just to put the filename if it's in the directory you're calling it from "my_file.txt" as well as using ../ to go up one level, etc.

OK thank you. I have checked and the files are located in the same folder as the program.

I am definitely entering correct names as well.
(I am not putting any quote marks around the name or anything like that, just straight:
XOR
which is the name of the file)

So what could be wrong?

Can you suggest another way please? (For the user to specify the files).

1) Does full paths work?
2) Make sure the files are not open in any program. If they are or you are unsure, you can use Unlocker or Lock Hunter to unlock them. Then try again.

There is nothing wrong with your first posted code and that is what you should do to get the paths in runtime!

You might want to add a

Code:

cout << trainingFile << endl;

in your error part along with cerr so you can print on the screen the actual path its trying to open. Then make sure that
1) The files exist
2) The files are not open/used by another process

Please do no promote such ridiculous debugging statements. Instead suggest a debugger.

So you want me to specify the full directory when console prompts for the file name?
Sorry not sure how to test it. But I have just used the file when it was hard coded into the program (as posted above).

The files are definitely not used anywhere else.

I am using the debugger and it fails on the first file.