Reading a file outside of main?

My programming skills are rusty after too much time away, and I am having a hard time figuring out the best way to do this.

I am working on a scanner and I want to read the file name from the command prompt within main. Then I want to call scanner() repeatedly to produce tokens. Scanner will be in a separate scanner.cpp file. What is the best way to do this in order to save the position of the file as I go in and out of the function? Who should actually read the file - main or scanner? It seems that scanner should, but I am a little hazy on how to do this.

It's really a design issue. You'll probably want to make your Scanner object (assuming you are actually making an object, and not just a stand alone function) independant. Make it:
a) Take a file name, and open it for scanning.
b) Take a file stream and scan it.
c) Both.
d) Something else snazzy you can think up.

It really depends on how you want your program to work. Do you want a Scanner object you can reuse? Or do you just want a parser function for this one time specific task? If you don't care about code reuse, simply make a function that takes a stream and reads from it, doing whatever it is you need it to do.

If you want your code to be reusable and well, more useful, make it so.

Quzah.