Book Image

Linux Shell Scripting Bootcamp

By : James K Lewis
Book Image

Linux Shell Scripting Bootcamp

By: James K Lewis

Overview of this book

Linux Shell Scripting Bootcamp is all about learning the essentials of script creation, validating parameters, and checking for the existence of files and other items needed by the script. We will use scripts to explore iterative operations using loops and learn different types of loop statements, with their differences. Along with this, we will also create a numbered backup script for backup files. Further, you will get well-versed with how variables work on a Linux system and how they relate to scripts. You’ll also learn how to create and call subroutines in a script and create interactive scripts. The most important archive commands, zip and tar, are also discussed for performing backups. Later, you will dive deeper by understanding the use of wget and curl scripts and the use of checksum and file encryption in further chapters. Finally, you will learn how to debug scripts and scripting best practices that will enable you to write a great code every time! By the end of the book, you will be able to write shell scripts that can dig data from the web and process it efficiently.
Table of Contents (19 chapters)
Linux Shell Scripting Bootcamp
Credits
About the Author
Acknowledgement
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
Index

ssh prompt


When I run a Linux system I tend to have at least 30 terminal windows open. Some of these are logged into the other machines in my house. As of this writing I am logged into laptop1, laptop4, and gabi1 (my girlfriend's laptop running Fedora 20). I found a while back that if the prompt were different on these terminals it was harder for me to get mixed up and type the right command but on the wrong computer. Needless to say that could be a disaster. For a while I would change the prompt manually but that got old very quickly. One day I found almost by accident a really cool solution to this problem. I have used this technique on Red Hat Enterprise Linux, Fedora, and CentOS and so it should work on your system as well (with maybe a little bit of tweaking).

These lines are in the $HOME/.bashrc file on all my systems:

# Modified 1/17/2014
set | grep XAUTHORITY
rc=$?
if [ $rc -eq 0 ] ; then
 PS1="\h \w # "
else
 PS1="\h \h \h \h \w # "
fi

So what this does is use the set command to grep...