go through the documentation.

go through the script.

• I've tried my best to explain it with the help of comments & kept it simple.

• only spaces, no tabs.
• no eval.
• always run shellcheck.
• use $(cmd) instead of `cmd`.
• script should remain posix (sh) compliant.
• use explicit path ./dir instead of dir.
• run shfmt -i 2 -ci -bn -s -p -w to format the script.
• script must remain readable and simple.
• no loss in flexibility and options.
• users choice should be prioritized.
• (I know this is stupid but) no conditional statements for now, but conditional operators can definitely be used.
• avoid set, using someone else's rule set for own script is a bad practice. Instead create your rules yourself this will definitely increase the size of code but output will also be definite. check this