Advanced.Linux.Networking..Roderick.Smith [Electronic resources] نسخه متنی

LPD Server Options for
Linux

UNIX systems generally, and Linux systems in particular,
support a large number of printing packages, most of which implement the LPD protocol.
In 2001, the three most popular printing packages for Linux are:

The original BSD LPD server
This package has long been the standard in Linux, and many Linux programs
assume that BSD LPD utilities are installed. For this reason, both LPRng and CUPS
emulate the BSD LPD tools, although to differing extents. BSD LPD is very
simple in its access control mechanisms, which is one of the reasons many
distributions have begun shifting away from it.

The LPRng package This system,
headquartered at target="_blank">http://www.astart.com/lprng/LPRngl ,
is designed as a more-or-less direct replacement for the BSD LPD system. It
deviates from the BSD LPD system in some of its configuration file formats, but
retains the BSD LPD format in other configuration files. It doesn't alter the
basic printing model, which requires that the application know something about
the printer to which it's printing (in Linux, most applications assume the
printer is a PostScript model).

The Common UNIX Printing System (CUPS)
This system, whose home page is http://www.cups.org , is a more radical
deviation from the BSD LPD system than is LPRng. Like LPRng, CUPS provides
workalike commands for some of the common tools, but CUPS uses an entirely
different set of printer configuration files. CUPS also provides information on
the printers it drives to applications that are written for CUPS. (To use this
feature over a network, both the client and the server must run CUPS.) In
addition to the LPD protocol, CUPS supports a newer network printing protocol,
IPP.

NOTE

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Other printing systems are common on some other UNIX-like OSs. For instance, versions of UNIX derived from SysV often use a different system. The SysV printing system can interoperate with the BSD system, but it uses different commands, such as lp rather than lpr to submit a print job.

href="http:// /JVXSL.asp?x=1&mode=section&sortKey=insertDate&sortOrder=desc&view=&xmlid=0-201-77423-2/ch09lev1sec2&open=true&title=New%20This%20Week&catid=&s=1&b=1&f=1&t=1&c=1&u=1#ch09table01#ch09table01"> Table 9.1 details
the printing systems that ship with several popular Linux distributions. Of
course, you can install a printing system on a distribution even if that
printing system doesn't ship with the distribution, but you may need to put
additional effort into configuring the software. Getting the software to start
up automatically may be a particular challenge, as described in href="http:// /?xmlid=0-201-77423-2/ch04#ch04"> Chapter 4 ,
Starting Servers.

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The distinction between "standard" and "alternative" printing systems in href="http:// /JVXSL.asp?x=1&mode=section&sortKey=insertDate&sortOrder=desc&view=&xmlid=0-201-77423-2/ch09lev1sec2&open=true&title=New%20This%20Week&catid=&s=1&b=1&f=1&t=1&c=1&u=1#ch09table01#ch09table01"> Table 9.1 is sometimes very slim. For instance, Mandrake gives you the option at installation time of using LPRng or CUPS. The default choice is LPRng, but it takes only a single mouse click to change this to CUPS. Debian doesn't install any printing system by default, so listing BSD LPD as the standard is entirely arbitrary.

Most Linux documentation has been written
with a BSD LPD system in mind. Most of this documentation applies almost as
well to an LPRng system, although the details of how to restrict access to a
networked print server differ between the two, as the following sections
illustrate. Most of the generic Linux printing documentation applies only
loosely to CUPS, because CUPS uses entirely different configuration files.