How to make –version custom command in linux

February 6, 2022

So, I just started to introduce myself with custom commands in Linux and created one but now I want it to be executed globally like this,
say my command is owncmd
#!/bin/bash
echo "Heya custom commands"

this works perfectly fine when I execute
$-owncmd
but I wanted to write the version or help page like :
$- owncmd –version OR owncmd –help

>Solution :

You should make a CLI (Command Line Interface).
To do this, you should parse the command line arguments, like --help and --version. You can access them with $1, $2, …

Here is an example on your code :

#!/bin/bash

cli_help() {
    # --help: Shows help message
    echo "
owncmd - Custom command

Usage:
    owncmd [options]

Options:
    --help / -h: Show this message and exit.
    --version / -V: Show version number and exit.
"
    exit
}

cli_version() {
    # --version: Show version
    echo "owncmd v1.0"
    exit
}

# Argument
case $1 in
    "--help"|"-h")
        cli_help
        ;;
    "--version"|"-V")
        cli_version
        ;;
esac
# Main program
echo "Heya custom commands"

The program look at the first argument $1.

If it is --help or -h: Show an help message (function cli_help) and exit
If it is --version or -V: Show version number (function cli_version) and exit