Expert Shell Scripting

Cover -- TOC$Contents -- About the Author -- About the Technical Reviewer -- Acknowledgments -- Introduction -- PART 1: Basic Scripting Techniques -- CH$CHAPTER 1 Shell Script Debugging -- Shell Trace Options -- Simple Output Statements -- Controlling Output with Debug Levels -- Simplifying Error Checking with a Function -- Manual Stepping -- CH$CHAPTER 2 Standard Function Library -- The Library File -- Some Useful Functions -- Using Your Library -- CH$CHAPTER 3 Date and Time Manipulation -- Date in Days -- Evaluating for the Current Day and Time -- CH$CHAPTER 4 Comparisons and Tests -- The Basics of Comparisons -- CH$CHAPTER 5 Accepting Command-Line Options, Switches, and Parameters -- CH$CHAPTER 6 Testing Variables and Assigning Defaults -- Setting Defaults -- Variable Substitution -- CH$CHAPTER 7 Indirect Reference Variables -- Log File Monitoring with Indirect Variables -- The Main Monitor Loop -- CH$CHAPTER 8 Shell Process Tree -- Process Tree Implemented Using Arrays -- Process Tree Implemented Using Indirect Variables -- Bourne Shell Implementation of a Process Tree -- CH$CHAPTER 9 Data Redirection -- Avoiding Confusion -- Common Redirection -- Access to User-Specified File Handles -- Descriptor Access from the Shell -- CH$CHAPTER 10 Piping Input to read -- Line-by-Line Option 1 -- Line-by-Line Option 2 -- Line-by-Line Option 3 -- Line-by-Line Option 4 -- Pipe to read Directly -- Process Input Word-by-Word -- PART 2: System Interaction and Advanced Techniques -- CH$CHAPTER 11 Math from the Shell -- expr -- Internal Shell Math -- bc -- dc -- CH$CHAPTER 12 cron -- crontab Entries -- Environment Problems -- Output Redirection -- CH$CHAPTER 13 Self-Linked Scripts -- CH$CHAPTER 14 Throttling Parallel Processes -- Parallel Processing with ksh -- Parallel Processing with bash -- CH$CHAPTER 15 Command-Line Editing and History -- Setting Up vi Editing -- Command and File Completion -- CH$CHAPTER 16 Scripting from the Command Line -- A Few Examples -- CH$CHAPTER 17 Automating User Input with expect -- A Shell Script to Customize Parameters for an expect Script -- An expect Script to Automate telnet -- CH$CHAPTER 18 User Input Timeout -- Manual Timeout Method -- Timeout Using stty -- General Timeout Utility -- CH$CHAPTER 19 Instant Keyboard Response -- CH$CHAPTER 20 Directory Copying -- Using cp -- Using tar -- Using find -- Using rsync -- CH$CHAPTER 21 A Brief Tour of the X Display Environment -- The Display -- X Traffic Through ssh -- X Applications Through a Third-Party System -- User-Profile Entry -- Root-Profile Entry -- Throw a Temporary Root Window -- CH$CHAPTER 22 X Navigation Window -- Navigation Window Usage -- Navigation Setup -- Navigation Window -- CH$CHAPTER 23 Command-Line E-mail Attachments -- uuencode -- MIME Encoding -- CH$CHAPTER 24 Text-Processing One-Liners -- Displaying Specific Fields -- Specifying the Field Separator -- Simple Pattern-Matching -- Matching Fields Against Several Values -- Determining the Number of Fields -- Determining the Last Field -- Determining the Second-to-Last Field -- Passing Variables to awk -- Using a Variable Passed to awk in a Condition -- Displaying a Range of Fields (Main M.