If you are a Linux operating system enthusiast or on a path to defining yourself as one, then crossing paths with shell scripting is completely inevitable. By definition, a shell script is a program designed to be executed on a Unix/Linux shell environment.
We can associate command-line interpreter (shell) with script operations like printing text, program execution, and file manipulation. Examples of popular Unix/Linux shell environments include GNU Bourne-Again Shell, Bourne Shell, Korn Shell, and C Shell.
Shell scripts that run in a Linux operating system environment are attributed with a .sh file extension. Consider the execution of the following shell script file:
$ ./onescript.sh
The execution of the above shell script is quite basic. If you mind the outlook of your shell scripts, then this article is for you. It will walk us through the installation as a usage of Gum to create glamorous shell scripts.
Gum is pre-packaged with ready-to-use and highly configurable utilities that enable Linux users to implement a few lines of code to successfully come up with applicable shell scripts and dotfiles aliases.
Installation of Gum in Linux
Before we can see what the Gum tool is capable of achieving, we need to install it on our Linux operating system distributions. Since it is not accessible in all major Linux package managers.
We are going to make use of the Homebrew package manager (installable on all major Linux distributions). If you do not already have Homebrew installed on your Linux distribution, refer to the Homebrew installation article that we wrote on it.
Once installed, you can use the Homebrew to install the gum tool.
$ brew install gum
Alternatively, you can install Gum on Debian/Ubuntu distributions using the following commands.
$ echo 'deb [trusted=yes] https://repo.charm.sh/apt/ /' | sudo tee /etc/apt/sources.list.d/charm.list $ sudo apt update && sudo apt install gum
On Arch and Manjaro Linux, use:
$ sudo pacman -S gum
Gum Basic Usage in Linux
Several useful commands are associated with Gum:
Choose from List of Choices
The following command makes it possible to select an option from several listed choices.
$ echo "Make a card pick on any card..." CARD=$(gum choose --height 15 {{A,K,Q,J},{10..2}}" "{♠,♥,♣,♦})
The above command execution should be able to point out the user choice.
Input
With the following command, a user is prompted to provide a standard input on the terminal:
$ gum input > respond.txt
If you need the input to be sensitive, make use of the --password flag.
$ gum input --password > respond.txt
Write
The following command provides multi-line input:
$ gum write > my_story.txt
Filter
Makes it possible to filter a list of values via fuzzy matching.
$ echo red >> colors.txt $ echo green >> colors.txt $ echo blue >> colors.txt $ cat colors.txt | gum filter > selector.txt
The execution of the above commands will lead to the following screen capture display:
We can filter through a list by typing a keyword.
Confirm
Makes it possible to confirm a user’s action before its execution.
$ gum confirm && rm new.txt || echo "Unable to locate file"
Spin
We can also display a spinner while a command/script executes while at the same time specifying the duration of the spin via the sleep command argument.
$ gum spin --spinner dot --title "Accessing LinuxShellTips Website..." -- sleep 10
If you were to create a shell script, your script file should have the following header.
#!/bin/sh
Make the script executable and run it.
$ chmod +x demo.sh $ ./demo.sh
More Gum usage references can be found in its user manual:
$ gum -h
To reference the usage of a command-like format, run:
$ gum format -h
This article guide makes it comfortably easy to begin and evolve in the creation of glamorous shell scripts.
