built using picocli

• Introduction
• Features
• Installation
• Example
• Motivation

I wanted in this project to build a utility that is handy, if you wanted a hash for a text or file or even multiple files, all you going to do is open the terminal or command prompt and type few commands and provide necessary arguments and that is it, you are one press away from your message digest.

with this handy tool you can hash text, a file or multiple files with various hashing functions with ease.

supported hashing functions are the following:

• SHA-1
• SHA-256
• SHA-384
• SHA-512
• SHA-512/224
• SHA-512/256
• SHA3-224
• SHA3-256
• SHA3-384
• SHA3-512

prerequisites

the only prerequisite is having installation of JDK 17 or higher.

the command called: hash

steps for installing:

1. go to Releases and scroll down to the Assets section
2. download cli-hashed.zip
3. unzip cli-hashed.zip folder, cd to cli-hashed folder, you will find 2 folders bin and repo and 1 text file called hashing_functions.txt
4. create a system environment variable(not user environment variable) called HASHING_FUNCTIONS containing the absolute path to hashing_functions.txt
5. after setting the system environment variable you can execute the hash.bat from the same directory of the launcher scripts i.e. hash.bat

NOTES

• to be able to call hash.bat from any directory, you need to add it into your PATH system or user environment variables.
• it is not mandatory to call hash.bat with extension you can call it like this hash
• type hash in your command-line and press Enter for help
• in repo there you will find the dependencies for the program
• in bin you will find the launcher scripts hash.bat and hash-linux for windows and linux respectively
• the directory of launcher scripts is bin, launcher scripts are hash.bat and hash-linux

Installed and tested in WSL2(Windows Subsystem of Linux 2), ubuntu distribution

prerequisites

the only prerequisite is having installation of JDK 17 or higher.

the command called: hash-linux

steps for installing JDK 17

1. sudo apt update && sudo apt upgrade
2. sudo apt install openjdk-17-jdk openjdk-17-jre
3. Once installed, verify the Java version using the following command: java -version
4. installation folder is located at /usr/lib/jvm/java-17-openjdk-amd64
5. you need to create JAVA_HOME environment variable and export it, to do so
   paste this command export JAVA_HOME="/usr/lib/jvm/java-17-openjdk-amd64" in .bashrc located in /$HOME/.bashrc

steps for installing

1. go to Releases and scroll down to the Assets section
2. download cli-hashed.zip
3. unzip cli-hashed.zip folder in /$HOME/
4. take the generated cli-hashed folder and place it in /$HOME/.local/bin/
5. cd into cli-hashed, you need to make the launcher script as executable using this command sudo chmod 755 hash-linux
6. as in installation of JDK 17 you need to paste this command export HASHING_FUNCTIONS="/$HOME/.local/cli-hashed/hashing_functions.txt" in .bashrc located in /$HOME/.bashrc
7. to be able to call the command hash-linux from anywhere you need to paste these two commands
   CLI_HASHED="/home/kiemkist/.local/cli-hashed"
PATH="$PATH:$CLI_HASHED/bin"
   in .bashrc located in /$HOME/.bashrc

NOTES

• I recommend that you arrange the commands in .bashrc in a proper way so it can be easy on you if you wanted to make any changes
• type hash-linux in your command-line and press Enter for help
• in repo there you will find the dependencies for the program
• in bin you will find the launcher scripts hash.bat and hash-linux for windows and linux respectively
• the directory of launcher scripts is bin, launcher scripts are hash.bat and hash-linux

examples pictures are taken from a run of the program on windows machine

help message:

hashing text:

hashing file:

hashing multiple files:

I was aiming to solidify my understanding of building an app that is designated for the command line, using picocli library eased the process for me, it abstracted a lot of layers to help me focus on the important things, I learned things about java like system properties, calling methods dynamically using .class(it's merely an object representing the class at runtime).

I ventured to git realm and discovered git tags, git Releases. I used semantic versioning specification to version my program, semantic versioning can be used to standardize the process of versioning of your software, I also Learned about one of the ways to package your software using launcher scripts, I used Maven appassembler plugin to achieve that.

It was such a great experience, I Learned a lot, dealing only with the command-line, it exposed me to different perspectives of Windows powershell and Linux bash shell.

I used picocli to build this TUI app, it was seamless and pleasant experience, documentation of picocli was clear and there was a lot of supportive examples.