Linux Shell Scripting Cookbook Table of Contents

Table of Contents

Preface
Chapter 1: Shell Something Out
Chapter 2: Have a Good Command
Chapter 3: File In, File Out
Chapter 4: Texting and Driving
Chapter 5: Tangled Web? Not At All!
Chapter 6: The Backup Plan
Chapter 7: The Old-boy Network
Chapter 8: Put on the Monitor's Cap
Chapter 9: Administration Calls
Index

• Preface

• Chapter 1: Shell Something Out
• Introduction
• Printing in the terminal
• Playing with variables and environment variables
• Doing math calculations with the shell
• Playing with file descriptors and redirection
• Arrays and associative arrays
• Visiting aliases
• Grabbing information about terminal
• Getting, setting dates, and delays
• Debugging the script
• Functions and arguments
• Reading the output of a sequence of commands
• Reading "n" characters without pressing Return
• Field separators and iterators
• Comparisons and tests

• Chapter 2: Have a Good Command
• Introduction
• Concatenating with cat
• Recording and playback of terminal sessions
• Finding files and file listing
• Playing with xargs
• Translating with tr
• Checksum and verification
• Sorting, unique and duplicates
• Temporary file naming and random numbers
• Splitting files and data
• Slicing file names based on extension
• Renaming and moving files in bulk
• Spell checking and dictionary manipulation
• Automating interactive input

• Chapter 3: File In, File Out
• Introduction
• Generating files of any size
• Intersection and set difference (A-B) on text files
• Finding and deleting duplicate files
• Making directories for a long path
• File permissions, ownership, and sticky bit
• Making files immutable
• Generating blank files in bulk
• Finding a symbolic link and its target
• Enumerating file type statistics
• Loopback files and mounting
• Creating ISO files, Hybrid ISO
• Finding difference between files, patching
• head and tail – printing the last or first 10 lines
• Listing only directories – alternative methods
• Fast command-line navigation using pushd and popd
• Counting number of lines, words, and characters in a file
• Printing directory tree

• Chapter 4: Texting and Driving
• Introduction
• Basic regular expression primer
• Searching and mining "text" inside a file with grep
• Column-wise cutting of a file with cut
• Frequency of words used in a given file
• Basic sed primer
• Basic awk primer
• Replacing strings from a text or file
• Compressing or decompressing JavaScript
• Iterating through lines, words, and characters in a file
• Merging multiple files as columns
• Printing the nth word or column in a file or line
• Printing text between line numbers or patterns
• Checking palindrome strings with a script
• Printing lines in the reverse order
• Parsing e-mail addresses and URLs from text
• Printing n lines before or after a pattern in a file
• Removing a sentence in a file containing a word
• Implementing head, tail, and tac with awk
• Text slicing and parameter operations

• Chapter 5: Tangled Web? Not At All!
• Introduction
• Downloading from a web page
• Downloading a web page as formatted plain text
• A primer on cURL
• Accessing Gmail from the command line
• Parsing data from a website
• Image crawler and downloader
• Web photo album generator
• Twitter command-line client
• define utility with Web backend
• Finding broken links in a website
• Tracking changes to a website
• Posting to a web page and reading response

• Chapter 6: The Backup Plan
• Introduction
• Archiving with tar
• Archiving with cpio
• Compressing with gunzip (gzip)
• Compressing with bunzip (bzip)
• Compressing with lzma
• Archiving and compressing with zip
• squashfs – the heavy compression filesystem
• Cryptographic tools and hashes
• Backup snapshots with rsync
• Version control based backup with Git
• Cloning hard drive and disks with dd

• Chapter 7: The Old-boy Network
• Introduction
• Basic networking primer
• Let's ping!
• Listing all the machines alive on a network
• Transferring files
• Setting up an Ethernet and wireless LAN with script
• Password-less auto-login with SSH
• Running commands on remote host with SSH
• Mounting a remote drive at a local mount point
• Multi-casting window messages on a network
• Network traffic and port analysis

• Chapter 8: Put on the Monitor's Cap
• Introduction
• Disk usage hacks
• Calculating execution time for a command
• Information about logged users, boot logs, and failure boot
• Printing the 10 most frequently-used commands
• Listing the top 10 CPU consuming process in a hour
• Monitoring command outputs with watch
• Logging access to files and directories
• Logfile management with logrotate
• Logging with syslog
• Monitoring user logins to find intruders
• Remote disk usage health monitor
• Finding out active user hours on a system

• Chapter 9: Administration Calls
• Introduction
• Gathering information about processes
• Killing processes and send or respond to signals
• which, whereis, file, whatis, and loadavg explained
• Sending messages to user terminals
• Gathering system information
• Using /proc – gathering information
• Scheduling with cron
• Writing and reading MySQL database from Bash
• User administration script
• Bulk image resizing and format conversion

• Index