Passing a file to a function

[pooshi]

I have a question about passing a data file into a function.
I want the user to enter data.txt, which is the file that holds the data for the program. My problem is when I run the program I can input anything into the variable filename via the cin statement and the program will execute.

How do I use filename in the LoadData function?

void LoadData(string filename);
int main()
{
......
cout<<"Please input the data file: ";
cin>>filename;
LoadData(filename);
......
}

void LoadData(string filename)
{

ifstream inFile; // declare file stream variable
inFile.open( "data.txt" ); // open file from disk

int num = 0; // counter to increment index of arrays
while( !inFile.eof() )
{
inFile >> weight[ num ]; // input weight from file
inFile >> year[ num ]; // input year from file
inFile >> month[ num ]; // input month from file
inFile >> day[ num ]; // input day from file
num++;
}

inFile.close(); // close file

}

[Bazzy]

Pass filename.c_str() to the file stream open method

[pooshi]

Thanks Bazzy. That was easy enough.
One more question.
In this LoadData function if the string "data.txt" was not entered correctly or it was anything but "data.txt" I have the following code to catch it:

if( !inFile )
{
cout << "Cannot open file.";
}
When the above occurs it outputs "Cannot open file."and the program stops.
From my understanding the stream enters a fail state and all output is stopped. In a function like this that returns void how do I deal with the fail state and continue the program?

[Bazzy]

if you want to quit a void function, simply call return; ( as you would do for a value-returning function but without any value )

[pooshi]

Thanks again Bazzy. I got it!