Technical information

215

lp Spooler (Unix Only)

The vfx command is modeled after the Unix lp spooler command. The similarities between the two allow you to

submit a fax as easily as printing a document.

Integration is accomplished by using an lp-compatible printer interface script. All Unix and Linux operating systems,

with the exception of IBM AIX, support ASCII text printer interface scripts. IBM AIX systems use a database

architecture that requires their printer interface scripts to be compiled. For AIX IBM interface scripts, refer to the IBM

AIX documentation.

Creating a printer destination for faxing

In order to use the lp spooler for fax interrogations, you need to create a printer destination called fax. The name can

be anything that works for your environment. This printer destination is created the same way a regular printer would

be created. The fax printer that you create should have a device port of /dev/null and a printer type of ASCII (or

another generic type).

When you create the fax printer destination, the operating system automatically puts a default printer script for that

printer in the interfaces directory. On most, but not all Unix and Linux systems, the interfaces directory is:

/usr/spool/lp/admins/lp/interfaces

Refer to your operating system documentation for additional information about adding an ASCII printer to your

system.

Creating a custom printer interface script

Once you have successfully added the new fax printer destination to your system, replace or modify the default

interface script to suit your particular environment and fax requirements. There are two methods for implementing this

interface script, each with its own unique advantages: LP faxing and LP merge faxing.

lp faxing

The first and most common option is to use the Unix lp command. Typically, the lp command accepts several

command line options that work well for sending a fax. In order for lp faxing to work correctly, two arguments must be

passed to the interface script:

Fax number

Name of the file you want to fax

The Unix lp command allows the use of the -o argument, which we will use to specify the fax number. The filename

can either be explicitly listed or a file can be redirected to the lp command. Either method works for lp faxing.

When creating the interface script, the most important line is the vfx command line. This is where options can be

added to make the lp faxing work in your environment. The sample script (Refer to lp faxing sample interface script

for more information) uses only a few options (login name, fax number and the file name). Additional options could be

added that would include a cover page and a user's default profile settings to send the fax. All command line options

available to the vfx command are also available within the interface script.