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ID:44171704
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页数:5页
时间:2019-10-19
《Components of an operating system操作系统的组成部分》由会员上传分享,免费在线阅读,更多相关内容在行业资料-天天文库。
1、1.Componentsofanoperatingsystem1操作系统的组成部分Ⅰ.TheShellofanOperatingSystemⅠ。操作系统的外壳Inordertoperformtheactionsrequestedbythecomputer’susers,anoperatingsystemmustbeabletocommunicatewiththoseusers.Theportionofanoperatingsystemthathandlesthiscommunicationisoftencalledtheshell.Moderns
2、hellsperformthistaskbymeansofagraphicaluserinterface(GUI)inwhichobjectstobemanipulated,suchasfilesandprograms,arerepresentedpictoriallyonthemonitorscreenasicons.Thesesystemsallowuserstoissuecommandstotheoperatingsystembypointingtotheseiconsbymeansofamouseandpressingabuttonont
3、hemouse.Oldershellscommunicatewithusersthroughtextualmessagesusingakeyboardandmonitorscreen.为了执行计算机的用户要求的操作,操作系统必须能够与用户进行通信。部分操作系统处理这种通信通常被称为壳。现代的外壳执行此任务通过一个图形用户界面(GUI)中,被操纵的对象,如文件和程序,代表pictoriallyon显示屏上的图标。这些系统允许用户发出指令操作系统指向这些图标通过鼠标按下鼠标上的按钮。老壳与用户通过textualmessages使用键盘和显示器。Alt
4、houghanoperatingsystem’sshellplaysanimportantroleinestablishingamachine’sfunctionality,thisshellismerelyaninterfacebetweenauserandtherealheartoftheoperatingsystem.Thisdistinctionbetweentheshellandtheinternalpartsoftheoperatingsystemisemphasizedbythefactthatsomeoperatingsystem
5、sallowausertoselectamongdifferentshellstoobtainthemostcompatibleinterfaceforthatparticularuser.UsersoftheUNIXoperatingsystem,forexample,canselectamongavarietyofshellsincludingtheBourneshell,theCshell,andtheKornshell.虽然一个操作系统的外壳在建立一台机器的功能中起着重要的作用,这个外壳只是一个用户和真正的心脏的操作系统之间的接口。这种区
6、分的外壳和操作系统的internalparts的事实是,许多操作系统允许用户选择不同的贝壳来获得特定用户最compatibleinterface强调。例如,在操作系统、用户,可以各种外壳包括BourneShell之间选择,C壳,和kornshell。Animportantcomponentwithintoday’sGUIshellsisthewindowmanager,whichallocatesblocksofspaceonthescreen,calledwindows,andkeepstrackofwhichapplicationisasso
7、ciatedwitheachwindow.Whenanapplicationwantstodisplaysomethingonthescreen,itnotifiesthewindowmanager,andthewindowmanagerplacesthedesiredimageinthewindowassignedtotheapplication.Inturn,whenamousebuttonisclicked,itisthewindowmanagerthatcomputesthemouse’slocationonthescreenandnot
8、ifiestheappropriateapplicationofthemouseaction.今天的龟壳的重要componentwith
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