Help ! to write a routine to print data

[S. T. Tan]

Hi, I am new for Xenix OS.
I was asked to write a business application program in C and run it in Xenix.
The application program should print out some forms (e.g. invoices etc)
either through a local printer attached to the dumb terminal, or a shared
printer attached to the host machine.
My questions are:
- What would be the best C routine to print out invoices ?
  Does it require to save the invoice in a file and then print it out using
  something like `system ("lpr <filename>");' ?
- How to setup a local printer (printer that's attached to the dumb terminal) ?
- Can a local printer be shared by other users ?

Any comment or example will be highly appreciated.

swie at umn-cs.cs.umn.edu