Shell scripting
Automate and learn how to improve your shell scripting skills with this series of articles.
Check if a directory or file exists
How to check if a directory or file exists within shell script?
Summary
Within a shell script we can test for the presence of directories and files. In this article we look at the basics and the more exotic options available. Testing the presence and type of a file can be done using the test command. For shell scripts, it is more common to use the [ command. Yes, it is an actual command. However, it may also be available as a so-called builtin and part of the shell.
Strip one or more characters from a variable or output
Want to delete one or more characters from a variable or piped output? There are multiple ways to achieve this using standard system utilities.
Making scripts (more) secure and safe
When you create a shell script, many things can go wrong. With a few basics you can catch errors easier and at the same time make your scripts (more) failsafe.
Summary
When you create a shell script, many things can go wrong. With a few basics you can catch errors easier and at the same time make your scripts (more) failsafe. The beauty of shell scripting is that with just a few steps this can be achieved! Empty variables: nounset (-u) A very typical issue in shell scripts is an incorrect or empty variable. Usually this happens due to a typo, but sometimes also assignments can be wrong.
Prompt for user input in a shell script
How to prompt users in your shell script, like asking answer Yes or No? In this article we look at options to achieve this.
Summary
Shell scripts can be powerful for automation. Sometimes, we want to ask the user for input. Let’s have a look at a few options that can be very handy for your next shell script! Fill a variable with input provided by the user If we like the user to provide us with some details, like a name, email address, or hostname, we can use the read command. read -p "What is your name?
5 things you didn’t know about shell scripting
Shell scripting doesn't have to be boring. Let's look at a few common things that many don't know about about shell scripts.
Summary
Our security auditing tool Lynis is a toolkit consisting of several shell scripts. Many users of the software actually never realized it was written as a bunch of shells scripts. Now that the secret is out, it is time to learn why we used shell scripting. Here are 5 reasons! 1. Shell scripting is powerful Yes, people asked us why our tool Lynis was not written in Perl, Python, Ruby, C++ etc.