Exercise 9.4 (Completed)

1. (Practice) A function named pFile() is to receive a filename as a reference to an ifstream
object. What declarations are required to pass a filename to pFile()?

// within the main() function
string fname = "pass.dat";
void pFile(ifstream&);
ifstream inFile;
inFile.open(fname.c_str());
pFile(inFile);

// within the pFile function
void pFile(ifstream& fileIn){

}

2. (Practice) Write a function named fcheck() that checks whether a file exists. The function
should accept an ifstream object as a formal reference parameter. If the file exists, the function
should return a value of 1; otherwise, the function should return a value of 0.

int fcheck(const std::string& name)
{
	std::ifstream infile(name);
	return infile.good();
}

3. (Practice) A data file consisting of a group of lines has been created. Write a function named
printLine() that reads and displays any line of the file. For example, the function called
printLine(fstream& fName,5); should display the fifth line of the passed object stream.

void printLine(ofstream& fileOut, int n)
{
	const int NUMLINES = 7;  // number of lines
	int count;
	string line;
	cout << "Please enter five lines of text : " << endl;
	for (count = 0; count < NUMLINES; ++count)
	{
		getline(cin, line);
		if (count == n){
		fileOut << line << endl;
	}
	}
	cout << "\nThe file has been successfully written.";
	return;
}

4. (Modify) Rewrite the getOpen() function used in Program 9.9 to incorporate the file-checking
procedures described in this section. Specifically, if the entered filename exists, an appropriate
message should be displayed. The user should be given the option of entering a new filename
or allowing the program to overwrite the existing file. Use the function written for Exercise 2
in your program.

bool fcheck(const std::string& name)
{
	std::ifstream infile(name);
	return infile.good();
}
int getOpen(ofstream& fileOut)
{
	string name;
	char letter;
	cout << "\nEnter a filename : ";
	getline(cin, name);

	if (fcheck(name) == true){
		cout << "File Exist"<< endl;
		cout << "Enter new file name Y/N" << endl;
		cin >> letter;
		if (letter == 'Y'){
			cout << "\nEnter a filename : ";
			getline(cin, name);
		}
		else{
			fileOut.open(name.c_str());
		}
	}
	fileOut.open(name.c_str());      // 

	
if (fileOut.fail())      // check for successful open
{
	cout << "Cannot open the file" << endl;

}
else
	return 1;
}