Mastering UNIX® Shell Scripting: Bash, Bourne, and Korn Shell Scripting for Programmers, System Administrators, and UNIX Gurus, Second Edition

Contents

Acknowledgments

Introduction

Part One The Basics of Shell Scripting

Chapter 1 Scripting Quick Start and Review

Case Sensitivity

UNIX Special Characters

Shells

Shell Scripts

Functions

Running a Shell Script

Declare the Shell in the Shell Script

Comments and Style in Shell Scripts

Control Structures

if … then statement

if … then … else statement

if … then … elif … (else) statement

for … in statement

while statement

until statement

case statement

Using break, continue, exit, and return

Here Document

Shell Script Commands

Symbol Commands

Variables

Command-Line Arguments

shift Command

Special Parameters $* and $@

Special Parameter Definitions

Double Quotes, Forward Tics, and Back Tics

Using awk on Solaris

Using the echo Command Correctly

Math in a Shell Script

Operators

Built-In Mathematical Functions

File Permissions, suid and sgid Programs

chmod Command Syntax for Each Purpose

To Make a Script Executable

To Set a Program to Always Execute as the Owner

To Set a Program to Always Execute as a Member of the File Owner's Group

To Set a Program to Always Execute as Both the File Owner and the File Owner's Group

Running Commands on a Remote Host

Setting Traps

User-Information Commands

who Command

w Command

last Command

ps Command

Communicating with Users

Uppercase or Lowercase Text for Easy Testing

Check the Return Code

Time-Based Script Execution

Cron Tables

Cron Table Entry Syntax

at Command

Output Control

Silent Running

Using getopts to Parse Command-Line Arguments

Making a ...