User Input File & Validation

[Troffe]

Hello! I've been struggling for a while, so hopefully you can help!

I need to:
#1 - validate that the file can be opened (think I've accomplished)
#2 - validate the data in the file. (f for female, m for male, the number is a GPA. (So validate the character is either f or m and reads that, validate GPA is a number)
#3 - Call the void function into main.

Sample Data for problem:

f2.5
f4.0
m1.4
m3.4
m2.9
f0.9
m1.2
m3.3

This is my code thus far for the void function:

void openFiles(string filenameIn, string filenameOut){

	ifstream inFile;
	ofstream outFile;
	
	cout << "Please enter the name of the file: " <<endl; //asks user for the file name
	getline (cin, filenameIn);
	filenameIn += ".txt"; //user doesn't need to  put .txt at the end of the file name.

	inFile.open(filenameIn.c_str());  //opens input file name 

	
	if (inFile.fail()) { //can't find file, it will fail
      cout << "Sorry, I was unable to open file." << endl;
      exit(1);
	}

}