file pointers

[firstTym]

If you have a pointer to a file/file stream like this: ifstream *file.
do you open and close a file like this:

file->open("Input.txt");

file-> close();

Can you read from the file by saying:

getline(*file, input) //input is string to store files contents

while(*file)
{
    //do comparisons
    getline(*file, input)
}

[Peter87]

Yes as long as file points to a valid ifstream object.

Are you sure you have to use pointers? They often just complicate things, and should not be used unless you have a good reason to.

[firstTym]

Ya, i have to use pointers...the task brief says to implement functions in a class and i have ifstream* file as a private variable.

Thing is the code i have compiles but when i run it, it gives me segmentation fault

[Peter87]

Can you perhaps show how you set the file pointer to point at the ifstream object?

[firstTym]

I'm not sure i did that or i know how to do that, all i did was try to open the file just as shown above

[Peter87]

file is just a pointer. To be able to call the ifstream functions you need an ifstream object.

I guess you are supposed to create the object with new?

file = new std::ifstream;

and then use delete to destruct the ifstream object when you no longer need it.

delete file;

[firstTym]

i have tried what you have suggested...but i doubt my code reads every line from the file as i only get one line which is somewhere in the middle as output.
In the code below i am trying to open and the file and to check if file is really open

	void fileOpen(string fileName)    
		{
			string word;
			file->open(fileName.c_str(), ios::in );
			if(file)
			{
				getline(*file,  word);
				while(file)
				{
					cout << word;
					getline(*file, word);
				}
			}
			
			else
				cout << "File not open";
		}

[Peter87]

You print no newlines so the whole file will be printed on one line.