How the Print Software Locates Printers

As shown in the following figure, the print software use more options to locate printers and printer configuration information.

Figure 2–4 How the Print Client Software Locates Printers

1. A user submits a print request from a print client by using the lp or lpr command. The user can specify a destination printer name or class in any of three styles:

   • Atomic style, which is the lp command and option followed by the printer name or class, as shown in this example.

     % lp -d neptune filename

   • POSIX style, which is the print command and option followed by server:printer, as shown in the following example.

     % lpr -P galaxy:neptune filename

   • Context-based style shown in this example.

     % lpr -d thisdept/service/printer/printer-name filename

2. The print command locates a printer and printer configuration information as follows:

   • It checks to see if the user specified a destination printer name or printer class in one of the three valid styles.

   • If the user didn't specify a printer name or class in a valid style, the command checks the user's PRINTER or LPDEST environment variable for a default printer name.

   • If neither environment variable for the default printer is defined, the command checks the sources configured for the printers database in the /etc/nsswitch.conf file.