What the Printer Interface Program Does

The LP print service interacts with other parts of the operating system. The print service uses a standard printer interface program to do the following:

• Initialize the printer port, if necessary. The standard printer interface program uses the stty command to initialize the printer port.

• Initialize the printer. The standard printer interface program uses the terminfo database and the TERM shell variable to find the appropriate control sequences.

• Print a banner page, if necessary.

• Print the correct number of copies specified by the print request.

The LP print service uses the standard interface program, found in the /usr/lib/lp/model directory, unless you specify a different program. You can create custom interface programs, but you must make sure that the custom program does not terminate the connection to the printer or interfere with proper printer initialization.