官术网_书友最值得收藏!

History of Printing in UNIX

In the early versions of UNIX, the line printer daemon (LPD) was used to spool text to a printer. This LPD also known as Berkeley printing system (BSD) is able to send any kind of file to a printer.

The model of this printing system consists of the following features:

  • A number of hosts request print services from a LPD process running on a host
  • The output of the print job will be produced when a file is sent as a request input
  • The print job will have a unique number from 0 to 999
  • Users who request print jobs shouldn't have their user name starting with digits
  • Apart from its main command lpd, the system also supports lpr (assign to queue), lpq (display the queue), lprm (remove from queue), and lpc (control the queue)

The biggest disadvantage with the Berkeley printing system is that it doesn't provide any feature for print jobs and filtering systems. These features were added in a new line printer (LP) system. The following URL shows information about this system in detail:

http://tools.ietf.org/html/rfc1179

Note

A printer that supports LPD/LPR is sometimes referred to as a "TCP/IP printer". The LPD/LPR protocol listens on TCP port 515.

The System V printing system is one of the several standard architectures for printing on the UNIX platform which uses the lp command. The following are some of the features of System V printing system:

  • This printing system is applicable to commercial System V based OS such as Solaris SCO OpenServer
  • Solaris has done a lot of modifications due to its open source project OpenSolaris by keeping original System V printing system intact

    Note

    OpenSolaris is an open source project created by Sun Microsystems to build a developer community around Solaris Operating System technology. You can get more information on this at: http://opensolaris.org/os/

  • Apart from its main command lp, System V uses other commands such as lpstat (shows the current print queue), cancel (deletes a job from the print queue), lpadmin (an administrative command to configure the print system), lpmove (an administrative command to configure moves jobs between queues)

CUPS emulates both System V and Berkeley print architectures at the interface level, though its internal architecture is different from both. We will see the architecture of CUPS with its features shortly.

主站蜘蛛池模板: 穆棱市| 涞源县| 高青县| 隆昌县| 东阿县| 沭阳县| 左权县| 平利县| 郴州市| 北安市| 嵩明县| 成武县| 武邑县| 凤凰县| 霍山县| 兴安盟| 偃师市| 綦江县| 河北省| 义马市| 万山特区| 天祝| 二连浩特市| 奇台县| 邳州市| 冷水江市| 莎车县| 赤城县| 花莲市| 公主岭市| 南靖县| 连州市| 敦煌市| 辽阳市| 长岛县| 柘荣县| 宁城县| 寿阳县| 临洮县| 登封市| 阳泉市|