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: 渭源县| 勐海县| 平利县| 崇左市| 九龙坡区| 海城市| 六安市| 德昌县| 略阳县| 县级市| 米脂县| 宣汉县| 黄石市| 蚌埠市| 武义县| 成安县| 和硕县| 连平县| 湖北省| 东兴市| 赤壁市| 通化市| 黔西| 宜川县| 禹州市| 鄂托克前旗| 新晃| 宝丰县| 同心县| 横峰县| 武邑县| 六盘水市| 桐庐县| 咸阳市| 康乐县| 正镶白旗| 广州市| 元江| 文水县| 长沙市| 盐亭县|