Linux Shell Scripting: Automating Command Line Tasks [Video]
Shell scripting involves writing a series of command for the shell to execute. It combines lengthy and repetitive sequences of commands into a single script, which can be stored and executed anytime. This reduces the effort required by the end user and the number of human mistakes.
You will write your first shell script and delve into the shell, to touch the power CLI which provides against the GUI. Also you will learn simple arguments and use getopts to make it a real Shell command. Then you will learn looping and functions for performing complex operations. You will then master Regex and regular expressions to validate your arguments. Finally, you will learn to write logs correctly and fight the temptation to use I/O redirections.
By the end of this course, you will be an expert at creating powerful shell scripts and will have explored the full possibilities of shells.
Style and Approach
This course starts with the simplest possible concept—listing the content of a folder—and leads you to an understanding of what a Linux OS System call is. You will see how programs interact with the OS, and what happens under the hood when you run a script of your own. You will solve tasks in the wrong way first and then learn to do so correctly, with the chance to compare using I/O redirection and the logger utility to write your own logs. The author will ask the question "What will happen?" before firing a command for a concept that has just been explained; that will be your queue to hit the Pause button and think.
|Course Length||2 hours 14 minutes|
|Date Of Publication||30 Nov 2018|
|The First Argument – The Path of the Script|
|The Order of the Arguments – Order Matters!|
|Types of Arguments – Strings, Numbers, and Special Characters|
|Parsing the Arguments – getopts|
|File I/O – Reading from a File and Writing to a File|
|Detaching from the Shell – Screen Utility and the &|
|Rewriting and Appending – The First Log|
|Environmental Variables – Playing with the PATH|
|Function Variables – Passing Arguments and Returning Values|
|Variable Scopes – It Is Not the Same Everywhere|
|Overloading – Redefining the Shell Commands|
|Naming – Naming Conventions|
|Branching – if/then/else and Case|
|Combining Loops and Branches – Nested Loops and Branches|
|Branching and Arguments – An Example init Script|
|Regex – Introduction to Regex|
|Regex Flavors – It Is Not the Same Everywhere|
|Globbing – Globbing Is Not Regex|
|Practice – Practicing Is the Only Way|
|Logging – Use Logger to Write Your Logs|
|Reading the Logs – cut, tail, head, and grep|
|System Calls – What strace Shows|
|The Last Call – Putting It All Together|