book

Linux Shell Scripting with Bash

by Ken O. Burtch

January 2004

Intermediate to advanced

432 pages

7h 49m

English

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Dedication
Notation Used in This BookThe Origin of BashWhen Is a Program a Shell Script?The Necessity of Structured Shell ProgrammingInstalling BashBash and Other Scripting Tools
The Origin of LinuxFiles and File SystemsDirectoriesInodes and LinksPipe and Socket FilesDevice Files
Bash KeywordsCommand BasicsCommand-Line EditingVariable Assignments and Displaying MessagesMultiple CommandsCommand HistoryDirectory CommandsSpecialized Navigation and HistoryThe Colon CommandReference Sectiondate Command Switchesstty Command Switcheshistory Command Switchespwd Command Switchesdirs Command Switches
Listing Filesprintf CommandGetting HelpFixing the DisplayWorking with FilesWorking with PeopleShell AliasesThe Bash Hash TableCustomizing Your PromptLong Command LinesCustomizing Command-Line EditingYour Session ProfileReference Sectionls Command Switchesprintf Formatting Codesprintf Backslash Codesrm Command Switchescp Command Switchesmv Command Switches
Creating a ScriptCreating a Well-Behaved ScriptThe HeaderGlobal DeclarationsSanity ChecksThe Main ScriptCleanupStopping a ScriptReading Keyboard InputBasic RedirectionStandard Output, Error, and InputBuilt-In Versus Linux CommandsThe Set and Shopt CommandsReference Sectioncommand Command Switchesenable Command Switchesread Command Switchessuspend Command Switches

Variable BasicsPredefined VariablesThe Effect of QuotationsVariable AttributesArraysExporting Variables and the Linux EnvironmentThe eval Commandstory.bash: A Story GeneratorReference SectionDeclare Command SwitchesBash Predefined Variables
ExpansionsThe Basic if CommandFile ExpressionsMultiple TestsStringsArithmetic ExpressionsLogical ExpressionsRelational OperationsBitwise OperationsSelf-Referential OperationsOther let Featurestemperature.bash: Converting Fahrenheit to CelsiusArithmetic TestsPattern RecognitionGlobbing OptionsFilename Brace Expansion ( {..} )Dollar Sign SubstitutionsANSI C Escape Expansion ($')Locale Translation ($")Variable Name Matching (!*)Variable Length (#)Default Values (:-)Assignment of Default Values (:=)Variable Existence Check (:?)Overriding a Default Value (:+)Substrings (:n)Substring Removal by Pattern (%, #, %%, and ##)Substring Replacement by Pattern (//)Command Result Substitution ( (..) )Arithmetic Expression Substitution ( ((..)) )Other Test Expressionsmixer.bash: HTML Color MixerReference SectionTest Command SwitchesTest Command String TestsCharacter ClassesASCII C Escape Expansion
Command Status Codesif Commandcase Commandwhile Loopuntil Loopfor LoopsEmbedded let ( ((..)) )Grouping Commands ( {..} )report.bash: Report Formatter
Shell Debugging FeaturesDebug TrapsVersion Control (CVS)Creating TranscriptsWatching Running ScriptsTiming Execution with TimeCreating Man PagesSource Code PatchesShell ArchivesReference Sectiontee Command SwitchesLinux Time Command SwitchesBash Time Command Format CodesLinux Time Command Format CodesShell Debugging Optionsshar Command Switches
Positional ParametersThe getopts CommandThe getopt CommandSubshellsReference Sectiongetopt Command Switches
Job ControlSignalsThe suspend CommandTrapsExit HandlersThe killall CommandBeing NiceProcess StatusReference Sectionjobs Command Switcheskill Command Switchesrenice Command Switchesps Command Switchesps Command Sort Codes
Working with PathnamesFile TruncationIdentifying FilesCreating and Deleting FilesMoving and Copying FilesMore Information About FilesTransferring Files Between Accounts (wget)Transferring Files with FTPTransferring Files with Secure FTP (sftp)Verifying FilesSplitting Large FilesTabs and SpacesTemporary FilesLock FilesNamed PipesProcess SubstitutionOpening FilesUsing head and tailFile StatisticsCuttingPastingColumnsFoldingJoiningMergingReference Sectiontype Command Switchesfile Command Switchesstat Command Switchesstatftime Command Format Codeswget Command Switchesftp Command Switchescsplit Command Switchesexpand Command Switchesunexpand Command Switchesmktemp Command Switcheshead Command Switchestail Command Switcheswc Command Switchescut Command Switchespaste Command Switchesjoin Command Switchesmerge Command Switches
Finding LinesLocating FilesFinding FilesSortingCharacter Editing (tr)File Editing (sed)Compressing FilesReference Sectiongrep Command Switchesfind Command Switchesfind -printf Formatting Codessort Command Switchestar Command Switchestr Command Switchessed Command Switchessed Editing Codes
The Linux ConsoleThe Console KeyboardThe Console Displaytputselect MenusCustom MenusReference Sectionshowkey Command Switchessetleds Command Switchesdumpkeys Command Switchessetterm Command Switchesdialog Command Switches
Running ScriptsThe Linux Execution EnvironmentThe Source Command (.)Switching Scripts with execWriting Recurring ScriptsWriting Continually Executing ScriptsShell FunctionsLocal VariablesRecursion and Nested FunctionsFunction AttributesReference Sectionexec Command Switchescrontab Command Switches
The Basic Linux Security ModelKnowing Who You Are (id)Transferring Ownership (chown/chgrp)Changing Access Rights (chmod)Default Access Rights (umask)setuid/setgid and ScriptsThe chroot CommandResource Limits (ulimit)Restricted ShellsSecure File Deletion (wipe)Reference Sectionid Command Switcheschown Command Switcheschmod Command Switchesulimit Command Switcheswipe Command Switches
SocketsClient-Server and Peer-to-PeerNetwork ClientsCGI ScriptingCGI Environment VariablesProcessing FormsBasic Web Page Stripping (lynx)Reference Sectionhost Command SwitchesCommon CGI Variableslynx Page-Stripping Switches
Associative Arrays Using Bash ArraysHash Tables Using Bash ArraysBinary Trees Using Bash ArraysWorking with PostgreSQL Databases (psql)Working with MySQL DatabasesReference Sectionpsql Command Switchesmysql Command Switches
The echo CommandMore Uses for setDate ConversionsCompletionsLocalesThe du CommandMemory Usagenoclobber and Forced OverwritingThe fc Command! Word Designators and ModifiersRunning Scripts from CJourney's EndReference Sectionecho Command Switchesecho Escape Codescompgen Command Switchescompgen Action Typescomplete Command Switchesdu Command Switches! Word Modifiers

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About the Author

Ken Burtch graduated with a Computer Science first class honors degree from Brock University in St. Catharines, Canada, and did his Masters work at Queen's University in Kingston, Canada. He has been using Linux since version 0.97, at a time before Linux was popular. He is the founder of PegaSoft Canada (http://www.pegasoft.ca), an association that promotes Linux advocacy, education, and development in southern Ontario. He has worked with a number of companies, including Mackenzie Financial Corporation, one of Canada's largest mutual fund companies. Ken is an active member of the Writers' Circle of Durham Region and his award-winning short story, “Distance,” was recently published in the “Signatures” anthology (ISBN 0973210001). ...