Linux Essentials 10th Edition

444 Pages·2012·1.36 MB·English

Linux Essentials
The LPI Introductory
Programme
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LinuxEssentials TheLPIIntroductoryProgramme
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©2012LinupFrontGmbH Darmstadt
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Authors: TobiasElsner,ThomasErker,AnselmLingnau
TechnicalEditor: AnselmLingnau [email protected]
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About Ourselves
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Contents
1 Computers,SoftwareandOperatingSystems 16
1.1 WhatIsAComputer,Anyway?. . . . . . . . . . . 17
1.2 ComponentsOfAComputer . . . . . . . . . . . 20
1.3 Software . . . . . . . . . . . . . . . . . . . 28
1.4 TheMostImportantOperatingSystems. . . . . . . . 30
1.4.1 WindowsAndOSX. . . . . . . . . . . . . 30
1.4.2 Linux . . . . . . . . . . . . . . . . . . 32
1.4.3 MoreDifferencesAndSimilarities. . . . . . . . 33
1.5 Summary. . . . . . . . . . . . . . . . . . . 35
2 LinuxandFreeSoftware 37
2.1 Linux: ASuccessStory . . . . . . . . . . . . . . 38
2.2 FreeOrOpenSource? . . . . . . . . . . . . . . 44
2.2.1 CopyrightAnd“FreeSoftware” . . . . . . . . 44
2.2.2 Licences . . . . . . . . . . . . . . . . . 49
2.2.3 TheGPL . . . . . . . . . . . . . . . . . 52
2.2.4 OtherLicences. . . . . . . . . . . . . . . 56
2.3 ImportantFreeSoftware . . . . . . . . . . . . . 61
2.3.1 Overview . . . . . . . . . . . . . . . . 61
2.4 OfficeandProductivityTools . . . . . . . . . . . 62
2.4.1 GraphicsandMultimediaTools . . . . . . . . 63
2.4.2 InternetServices . . . . . . . . . . . . . . 65
2.4.3 InfrastructureSoftware. . . . . . . . . . . . 65
2.4.4 ProgrammingLanguagesandDevelopment . . . . 66
2.5 ImportantLinuxDistributions . . . . . . . . . . . 68
2.5.1 Overview . . . . . . . . . . . . . . . . 68
2.5.2 RedHat . . . . . . . . . . . . . . . . . 69
2.5.3 SUSE . . . . . . . . . . . . . . . . . . 70
2.5.4 Debian . . . . . . . . . . . . . . . . . 72
2.5.5 Ubuntu . . . . . . . . . . . . . . . . . 74
2.5.6 Others. . . . . . . . . . . . . . . . . . 75
2.5.7 DifferencesandSimilarities . . . . . . . . . . 76
3 FirstStepswithLinux 82
3.1 LoggingInandOut . . . . . . . . . . . . . . . 83
3.2 DesktopEnvironmentandBrowser . . . . . . . . . 87
3.2.1 GraphicalDesktopEnvironments . . . . . . . . 87
3.2.2 Browsers. . . . . . . . . . . . . . . . . 89
3.2.3 TerminalsandShells. . . . . . . . . . . . . 90
3.3 CreatingandModifyingTextFiles. . . . . . . . . . 92
4 Who’sAfraidOfTheBigBadShell? 101
4.1 Why? . . . . . . . . . . . . . . . . . . . . 102
4.1.1 WhatIsTheShell? . . . . . . . . . . . . . 103
4.2 Commands . . . . . . . . . . . . . . . . . . 106
4.2.1 WhyCommands?. . . . . . . . . . . . . . 106
4.2.2 CommandStructure. . . . . . . . . . . . . 106
4.2.3 CommandTypes . . . . . . . . . . . . . . 108
4.2.4 EvenMoreRules . . . . . . . . . . . . . . 110
5 GettingHelp 113
5.1 Self-Help. . . . . . . . . . . . . . . . . . . 114
5.2 Thehelp Commandandthe--help Option . . . . . . . 115
5.3 TheOn-LineManual . . . . . . . . . . . . . . 116
5.3.1 Overview . . . . . . . . . . . . . . . . 116
5.3.2 Structure. . . . . . . . . . . . . . . . . 117
5.3.3 Chapters . . . . . . . . . . . . . . . . . 118
5.3.4 DisplayingManualPages. . . . . . . . . . . 119
5.4 InfoPages . . . . . . . . . . . . . . . . . . 122
5.5 HOWTOs. . . . . . . . . . . . . . . . . . . 124
5.6 FurtherInformationSources. . . . . . . . . . . . 125
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6 Files: CareandFeeding 130
6.1 FileandPathNames. . . . . . . . . . . . . . . 131
6.1.1 FileNames . . . . . . . . . . . . . . . . 131
6.1.2 Directories . . . . . . . . . . . . . . . . 134
6.1.3 AbsoluteandRelativePathNames . . . . . . . 135
6.2 DirectoryCommands . . . . . . . . . . . . . . 138
6.2.1 TheCurrentDirectory: cd &Co. . . . . . . . . 138
6.2.2 ListingFilesandDirectories—ls . . . . . . . . 139
6.2.3 CreatingandDeletingDirectories: mkdir andrmdir . . 143
6.3 FileSearchPatterns . . . . . . . . . . . . . . . 145
6.3.1 SimpleSearchPatterns. . . . . . . . . . . . 145
6.3.2 CharacterClasses. . . . . . . . . . . . . . 147
6.3.3 Braces . . . . . . . . . . . . . . . . . . 149
6.4 HandlingFiles . . . . . . . . . . . . . . . . . 151
6.4.1 Copying,MovingandDeleting—cp andFriends. . . 151
6.4.2 LinkingFiles—ln andln -s . . . . . . . . . . 155
6.4.3 DisplayingFileContent—more andless . . . . . . 160
6.4.4 SearchingFiles—find . . . . . . . . . . . . 162
6.4.5 FindingFilesQuickly—locate andslocate . . . . . 167
7 RegularExpressions 173
7.1 RegularExpressions: TheBasics . . . . . . . . . . 174
7.1.1 RegularExpressions: Extras . . . . . . . . . . 175
7.2 SearchingFilesforText—grep . . . . . . . . . . . 178
8 StandardI/OandFilterCommands 184
8.1 I/ORedirectionandCommandPipelines . . . . . . . 185
8.1.1 StandardChannels . . . . . . . . . . . . . 185
8.1.2 RedirectingStandardChannels. . . . . . . . . 188
8.1.3 CommandPipelines. . . . . . . . . . . . . 192
8.2 FilterCommands . . . . . . . . . . . . . . . . 195
8.3 ReadingandWritingFiles. . . . . . . . . . . . . 197
8.3.1 OutputtingandConcatenatingTextFiles—cat . . . 197
8.3.2 BeginningandEnd—head andtail. . . . . . . . 198
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8.4 DataManagement . . . . . . . . . . . . . . . 201
8.4.1 SortedFiles—sort anduniq . . . . . . . . . . 201
8.4.2 ColumnsandFields—cut,paste etc. . . . . . . . 210
9 MoreAboutTheShell 217
9.1 SimpleCommands: sleep,echo,anddate. . . . . . . . 218
9.2 ShellVariablesandTheEnvironment. . . . . . . . . 221
9.3 CommandTypes–Reloaded. . . . . . . . . . . . 224
9.4 TheShellAsAConvenientTool . . . . . . . . . . 228
9.5 CommandsFromAFile . . . . . . . . . . . . . 233
9.6 TheShellAsAProgrammingLanguage. . . . . . . . 235
10 TheFileSystem 244
10.1 Terms . . . . . . . . . . . . . . . . . . . . 245
10.2 FileTypes. . . . . . . . . . . . . . . . . . . 247
10.3 TheLinuxDirectoryTree . . . . . . . . . . . . . 249
10.4 DirectoryTreeandFileSystems. . . . . . . . . . . 263
11 ArchivingandCompressingFiles 268
11.1 ArchivalandCompression . . . . . . . . . . . . 269
11.2 ArchivingFilesUsingtar . . . . . . . . . . . . . 271
11.3 CompressingFileswithgzip . . . . . . . . . . . . 277
11.4 CompressingFileswithbzip2. . . . . . . . . . . . 280
11.5 ArchivingandCompressingFilesUsingzip andunzip. . . 282
12 IntroductiontoSystemAdministration 290
12.1 SystemAdministrationBasics . . . . . . . . . . . 291
12.2 SystemConfiguration . . . . . . . . . . . . . . 294
12.3 Processes. . . . . . . . . . . . . . . . . . . 297
12.4 PackageManagement . . . . . . . . . . . . . . 304
13 UserAdministration 309
13.1 Basics . . . . . . . . . . . . . . . . . . . . 310
13.1.1 WhyUsers?. . . . . . . . . . . . . . . . 310
13.1.2 UsersandGroups . . . . . . . . . . . . . 312
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13.1.3 PeopleandPseudo-Users . . . . . . . . . . . 316
13.2 UserandGroupInformation. . . . . . . . . . . . 318
13.2.1 The/etc/passwd File . . . . . . . . . . . . . 318
13.2.2 The/etc/shadow File . . . . . . . . . . . . . 322
13.2.3 The/etc/group File . . . . . . . . . . . . . 327
13.2.4 The/etc/gshadow File . . . . . . . . . . . . . 328
13.3 ManagingUserAccountsandGroupInformation . . . . 330
13.3.1 CreatingUserAccounts . . . . . . . . . . . 330
13.3.2 Thepasswd Command . . . . . . . . . . . . 333
13.3.3 DeletingUserAccounts . . . . . . . . . . . 336
13.3.4 ChangingUserAccountsandGroupAssignment . . 337
13.3.5 ChangingUserInformationDirectly—vipw. . . . . 338
13.3.6 Creating,ChangingandDeletingGroups . . . . . 339
14 AccessControl 344
14.1 TheLinuxAccessControlSystem . . . . . . . . . . 345
14.2 AccessControlForFilesAndDirectories . . . . . . . 346
14.2.1 TheBasics . . . . . . . . . . . . . . . . 346
14.2.2 InspectingandChangingAccessPermissions. . . . 347
14.2.3 SpecifyingFileOwnersandGroups—chown andchgrp . 350
14.3 ProcessOwnership . . . . . . . . . . . . . . . 352
14.4 SpecialPermissionsforExecutableFiles. . . . . . . . 353
14.5 SpecialPermissionsforDirectories . . . . . . . . . 355
15 LinuxNetworking 361
15.1 NetworkingBasics . . . . . . . . . . . . . . . 362
15.1.1 IntroductionandProtocols . . . . . . . . . . 362
15.1.2 AddressingandRouting . . . . . . . . . . . 364
15.1.3 NamesandtheDNS. . . . . . . . . . . . . 368
15.1.4 IPv6 . . . . . . . . . . . . . . . . . . 369
15.2 LinuxAsANetworkingClient . . . . . . . . . . . 373
15.2.1 Requirements . . . . . . . . . . . . . . . 373
15.2.2 Troubleshooting . . . . . . . . . . . . . . 375
A SampleSolutions 387
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B ExampleFiles 411
C LinuxEssentialsCertification 416
C.1 ExamObjectiveOverview. . . . . . . . . . . . . 417
C.2 ExamObjectivesForLinuxEssentials . . . . . . . . . 419
D CommandIndex 431
Index 436
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