Professional Unix Shell Programming - Contents

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Professional Unix Shell Programming
Contents

Professional Unix Shell Programming

Who is this book for?

Selecting the right shell

The Korn Shell Language.

Discovering the Version

Getting the Korn Shell

Source Code and Examples from this book.

Command line options

Rules of engagement

Interrupting the shell

Sytem login scripts

User login scripts

Simple Commands

Typing commands and In-line Editing Options

Emacs Editing Mode.

Vi Editing Mode.

Setting options in the shell

stdin, stdout, stderr

The symbol & (background)

The co-process symbol |&

The symbol && (and)

The symbol || (or)

The symbol > ( redirect out )

The symbol >> ( redirect append )

The < symbol (redirect input )

The << symbol (Here Document)

Basic File Descriptors

More Input/Output Redirection.

Redirection symbol <

Redirectin symbol >

The >| symbol ( redirect clobber )

Redirection Order

Basic Definitions

Special Command

Special Characters

Escape Sequences

Parameter Substitution

Active Variables

Reference Variables

Using Variables.

Compound assignments

Special shell variables

Parameter Expansion

String manipulation.

Parameter Replacement

Parameter Field Separation

Creating temporary files

Positional parameters

Special Variables

PS1, PS2,PS3,PS4

Regular Expressions and Pattern Matching

Collating elements:

RE Special Characters

The special characters are:

Behavior of special characters:

BRE Expression Anchoring

Classes of characters

Matching a range of characters

BREs Matching Multiple Characters

Matching a Specific Number Of Repetitions of a Pattern

Start of the Line and End of the Line

Matching one of two strings

Patterns in the Korn Shell

[[ string == pattern ]]

[[ string != pattern ]]

<operator>(<pattern-list>)

The Pattern Operators

Where patterns are used

expr (RE Operator)

Searching and substrings.

ksh88 and Posix replacements

Shell Line Processes

~ Tilde Substitution.

Process Substitution.

Grouping Commands

Command Substitution

exec <redirection>

. file (dot file or sourcing)

File Name Expansion.

The test commands; test, [, [[

cat and the Here-Document

Autoload functions.

built-in math functions

Arithmetic Evaluation

Base conversion

expr - evaluate arguments as an expression

[[ integer test operators

Built-in Commands (Special Commands).

builtin -ds -f file name ...

getconf [-a] name

Important Utilities

sed - stream editor

SED Regular Expressions

SED Function Language

Branching/Labels:

Substitute/Replace:

cut - select portions of each line of a file

tr - translate characters

Special clauses

Flow Control Statements

String Functions

Arithmetic Functions

Built-In Variables

Other Common Commands

basename, dirname

expand, unexpand

rsh, remsh, rexec

Shell syntax check

Active Variables

trap <list> DEBUG example debugger

Typical Common mistakes

trap <list> EXIT

set -e or set –o errexit

set –v or set –o verbose

set –x or set –o xtrace

typeset –ft function

Processing Arguments

getopt optstring arg ...

Shift through your arguments

Graphical shells

history, fc - process command history list

getting other shells

rksh, restricted shell – restricted shell command interpreter

Reissuing Commands

Finding File Names

Building your own Tools

Tip #1: Naming the script

Tip #2: Processing files line by line

Tip #3: Creating an infrastructure

Tip #4: Use a usage statement

Tip #5: Case tips

Use a typeset to allow acceptance of an upper or lower case answer to a question. Its easier than a case statement.

Tip #6: Give your users a default response

Tip #7: Connect to a socket from a shell script

Tip #8: Shifting variables in an array

Tip #9: A wrapper for read

Utility #1: Returning to where you have already been

Utility #2: Progress indicator

Utiltiy #3: Viewing man pages

Utility #4: Save

Utility #5: Which program is selected by the PATH?

Utility #6: Pstree and recursion in the shell.

Utility #7: Shell Archives

Utility #8: Logging Command

Utility #9: Changing a built-in command – replace cd

Utility #10: Ideas for using string manipulation on paths

Utility #11: Skipping comments and blank lines

Utility #12: Print a directory tree

Coding Standards

Extending the Korn Shell

Locating important files and information: