Book Image

Mastering Linux Shell Scripting

By : Andrew Mallett
Book Image

Mastering Linux Shell Scripting

By: Andrew Mallett

Overview of this book

Shell scripting is a quick method to prototype a complex application or a problem by automating tasks when working on Linux-based systems. Using both simple one-line commands and command sequences complex problems can be solved with ease, from text processing to backing up sysadmin tools. In this book, you’ll discover everything you need to know to master shell scripting and make informed choices about the elements you employ. Get to grips with the fundamentals of creating and running a script in normal mode, and in debug mode. Learn about various conditional statements' code snippets, and realize the power of repetition and loops in your shell script. Implement functions and edit files using the Stream Editor, script in Perl, program in Python – as well as complete coverage of other scripting languages to ensure you can choose the best tool for your project.
Table of Contents (21 chapters)
Mastering Linux Shell Scripting
About the Author
About the Reviewer

Using code snippets

All we mean by the term code snippets is a prepared code that we can read into our current script. This is especially easy with vim being able to read the contents of other text files during editing:

:r <path-and-filename>

For example, if we need to read the contents of a file called if located in $HOME/snippets, we will use the following key sequences in vim:

:r $HOME/snippets/if

The contents of this file is read into the current document below the current cursor position. In this way, we can make the code snippets as complex as we need and maintain the correct indentations to aide readability and consistency.

So, we will make it our duty to always create a snippets directory in our home directory:

$ mkdir -m 700 $HOME/snippets

It is not required to share the directory, so it is good practice to set the mode to 700 or private to the user when it is being created.

When creating snippets, it is your choice to use a pseudo-code or real examples. My preference is...