book

Shell Programming in Unix, Linux and OS X, Fourth Edition

Name: Shell Programming in Unix, Linux and OS X, Fourth Edition
ISBN: 9780134496696

by Stephen G. Kochan, Patrick Wood

August 2016

Intermediate to advanced

456 pages

11h 17m

English

Addison-Wesley Professional

Read now

Unlock full access

About This E-Book
Title Page
Copyright Page
Developer’s Library
Contents at a Glance
Table of Contents
About the Authors
We Want to Hear from You!
Reader Services
Introduction
How This Book Is OrganizedAccessing the Free Web Edition

1. A Quick Review of the Basics
Some Basic CommandsDisplaying the Date and Time: The date CommandFinding Out Who’s Logged In: The who CommandEchoing Characters: The echo CommandWorking with FilesListing Files: The ls CommandDisplaying the Contents of a File: The cat CommandCounting the Number of Words in a File: The wc CommandCommand OptionsMaking a Copy of a File: The cp CommandRenaming a File: The mv CommandRemoving a File: The rm CommandWorking with DirectoriesThe Home Directory and PathnamesDisplaying Your Working Directory: The pwd CommandChanging Directories: The cd CommandMore on the ls CommandCreating a Directory: The mkdir CommandCopying a File from One Directory to AnotherMoving Files Between DirectoriesLinking Files: The ln CommandRemoving a Directory: The rmdir CommandFilename SubstitutionThe AsteriskMatching Single CharactersFilename NuancesSpaces in FilenamesOther Weird CharactersStandard Input/Output, and I/O RedirectionStandard Input and Standard OutputOutput RedirectionInput RedirectionPipesFiltersStandard ErrorMore on CommandsTyping More Than One Command on a LineSending a Command to the BackgroundThe ps CommandCommand Summary
2. What Is the Shell?
The Kernel and the UtilitiesThe Login ShellTyping Commands to the ShellThe Shell’s ResponsibilitiesProgram ExecutionVariable and Filename SubstitutionI/O RedirectionHooking up a PipelineEnvironment ControlInterpreted Programming Language
3. Tools of the Trade
Regular ExpressionsMatching Any Character: The Period (.)Matching the Beginning of the Line: The Caret (^)Matching the End of the Line: The Dollar Sign $Matching a Character Set: The [...] ConstructMatching Zero or More Characters: The Asterisk (*)Matching a Precise Number of Subpatterns: \{...\}Saving Matched Characters: $...$cutThe -d and -f OptionspasteThe -d OptionThe -s OptionsedThe -n OptionDeleting LinestrThe -s OptionThe –d OptiongrepRegular Expressions and grepThe -v OptionThe -l OptionThe -n OptionsortThe -u OptionThe -r OptionThe -o OptionThe -n OptionSkipping FieldsThe -t OptionOther OptionsuniqThe -d OptionOther Options
4. And Away We Go
Command FilesCommentsVariablesDisplaying the Values of VariablesUndefined Variables Have the Null ValueFilename Substitution and VariablesThe ${variable} ConstructBuilt-in Integer Arithmetic
5. Can I Quote You on That?
The Single QuoteThe Double QuoteThe BackslashUsing the Backslash for Continuing LinesThe Backslash Inside Double QuotesCommand SubstitutionThe Back QuoteThe $(...) ConstructThe expr Command
6. Passing Arguments
The $# VariableThe $* VariableA Program to Look Up Someone in the Phone BookA Program to Add Someone to the Phone BookA Program to Remove Someone from the Phone Book${n}The shift Command
7. Decisions, Decisions
Exit StatusThe $? VariableThe test CommandString OperatorsAn Alternative Format for testInteger OperatorsFile OperatorsThe Logical Negation Operator !The Logical AND Operator –aParenthesesThe Logical OR Operator –oThe else ConstructThe exit CommandA Second Look at the rem ProgramThe elif ConstructYet Another Version of remThe case CommandSpecial Pattern-Matching CharactersThe -x Option for Debugging ProgramsBack to the caseThe Null Command :The && and || Constructs
8. 'Round and 'Round She Goes
The for CommandThe $@ VariableThe for Without the ListThe while CommandThe until CommandMore on LoopsBreaking Out of a LoopSkipping the Remaining Commands in a LoopExecuting a Loop in the BackgroundI/O Redirection on a LoopPiping Data into and out of a LoopTyping a Loop on One LineThe getopts Command
9. Reading and Printing Data
The read CommandA Program to Copy FilesSpecial echo Escape CharactersAn Improved Version of mycpA Final Version of mycpA Menu-Driven Phone ProgramThe $$ Variable and Temporary FilesThe Exit Status from readThe printf Command
10. Your Environment
Local VariablesSubshellsExported Variablesexport -pPS1 and PS2HOMEPATHYour Current DirectoryCDPATHMore on SubshellsThe .CommandThe exec CommandThe (...) and { ...; } ConstructsAnother Way to Pass Variables to a SubshellYour .profile FileThe TERM VariableThe TZ Variable
11. More on Parameters
Parameter Substitution${parameter}${parameter:-value}${parameter:=value}${parameter:?value}${parameter:+value}Pattern Matching Constructs${#variable}The $0 VariableThe set CommandThe -x Optionset with No ArgumentsUsing set to Reassign Positional ParametersThe -- OptionOther Options to setThe IFS VariableThe readonly CommandThe unset Command
12. Loose Ends
The eval CommandThe wait CommandThe $! VariableThe trap Commandtrap with No ArgumentsIgnoring SignalsResetting TrapsMore on I/O<&- and >&-In-line Input RedirectionShell ArchivesFunctionsRemoving a Function DefinitionThe return CommandThe type Command
13. Rolo Revisited
Data Formatting ConsiderationsroloaddludisplayremchangelistallSample Output
14. Interactive and Nonstandard Shell Features
Getting the Right ShellThe ENV FileCommand-Line EditingCommand HistoryThe vi Line Edit ModeAccessing Commands from Your HistoryThe emacs Line Edit ModeAccessing Commands from Your HistoryOther Ways to Access Your HistoryThe history CommandThe fc CommandThe r CommandFunctionsLocal VariablesAutomatically Loaded FunctionsInteger ArithmeticInteger TypesNumbers in Different BasesThe alias CommandRemoving AliasesArraysJob ControlStopped Jobs and the fg and bg CommandsMiscellaneous FeaturesOther Features of the cd CommandTilde SubstitutionOrder of SearchCompatibility Summary
A. Shell Summary
StartupCommandsCommentsParameters and VariablesShell VariablesPositional ParametersSpecial ParametersParameter SubstitutionCommand Re-entryThe fc Commandvi Line Edit ModeQuotingTilde SubstitutionArithmetic ExpressionsFilename SubstitutionI/O RedirectionExported Variables and Subshell ExecutionThe (...) ConstructThe { ...; } ConstructMore on Shell VariablesFunctionsJob ControlShell JobsStopping JobsCommand SummaryThe : CommandThe . CommandThe alias CommandThe bg CommandThe break CommandThe case CommandThe cd CommandThe continue CommandThe echo CommandThe eval CommandThe exec CommandThe exit CommandThe export CommandThe false CommandThe fc CommandThe fg CommandThe for CommandThe getopts CommandThe hash CommandThe if CommandThe jobs CommandThe kill CommandThe newgrp CommandThe pwd CommandThe read CommandThe readonly CommandThe return CommandThe set CommandThe shift CommandThe test CommandThe times CommandThe trap CommandThe true CommandThe type CommandThe umask CommandThe unalias CommandThe unset CommandThe until CommandThe wait CommandThe while Command
B. For More Information
Online DocumentationDocumentation on the WebBooksO’Reilly & AssociatesPearson
Index
Inside Front Cover
Inside Back Cover
Code Snippets

Content preview from Shell Programming in Unix, Linux and OS X, Fourth Edition

Introduction

It’s no secret that the family of Unix and Unix-like operating systems has emerged over the last few decades as the most pervasive, most widely used group of operating systems in computing today. For programmers who have been using Unix for many years, this came as no surprise: The Unix system provides an elegant and efficient environment for program development. That’s exactly what Dennis Ritchie and Ken Thompson sought to create when they developed Unix at Bell Laboratories way back in the late 1960s.

Note

Throughout this book we’ll use the term Unix to refer generically to the broad family of Unix-based operating systems, including true Unix operating systems such as Solaris as well as Unix-like operating systems such as Linux ...

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.

Read now

Unlock full access

More than 5,000 organizations count on O’Reilly

O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.

Julian F.

Head of Cybersecurity

I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.

Addison B.

Field Engineer

I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.

Amir M.

Data Platform Tech Lead

I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.

Mark W.

Embedded Software Engineer

Publisher Resources

ISBN: 9780134496696Purchase book

Cloud Computing

Data Engineering

Data Science

AI & ML

Programming Languages

Software Architecture

IT/Ops

Security

Design

Business

Soft Skills

Shell Programming in Unix, Linux and OS X, Fourth Edition

by Stephen G. Kochan, Patrick Wood

Introduction

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.