Headerize Your Bash Scripts

If you've ever stumbled across my code — especially the shell scripts — you'll notice something consistent: they all start with a bold ASCII header.

It’s not just for aesthetics (though it does look cool 😎). It helps me track:

• When the script was created
• Who wrote it (me 👋)
• And when it was last modified

Manually updating that info? Nah. Too tedious.

So I built a lightweight CLI tool called headerize that automatically adds or updates headers in my .sh or .py files.

Let me walk you through how I did it — and how you can too.

⚡️ Why Automate Headers?

If you write a lot of scripts, a standardized header saves time and avoids confusion. Here’s what my headers look like:

#!/bin/bash

#
#       ███╗   ██╗██╗██╗  ██╗ █████╗ ██████╗ ███████╗
#       ████╗  ██║██║██║  ██║██╔══██╗██╔══██╗██╔════╝
#       ██╔██╗ ██║██║███████║███████║██████╔╝███████╗
#       ██║╚██╗██║██║██╔══██║██╔══██║██╔══██╗╚════██║
#       ██║ ╚████║██║██║  ██║██║  ██║██║  ██║███████║
#       ╚═╝  ╚═══╝╚═╝╚═╝  ╚═╝╚═╝  ╚═╝╚═╝  ╚═╝╚══════╝
#       DRAFTED BY [https://nih.ar] ON 10-04-2021.
#       SOURCE [myscript.sh] LAST MODIFIED ON 06-04-2025.
#

Now, imagine doing that manually every time, and updating the date whenever you tweak something. This tool does it all — and even smartly preserves the original "drafted" date.

🧪 Meet headerize

This is a Bash script that:

• Adds a full header if one doesn't exist
• Updates the "last modified" date if a header is already present
• Works with .sh, .py, and any other files you want to include

Let’s set it up.

Step 1: Create the headerize Script

📁 Location: I like to keep my CLI tools in ~/bin, but you can place it wherever you like.

mkdir -p ~/bin
touch ~/bin/headerize
chmod +x ~/bin/headerize

Main Script:

#!/bin/bash

website="https://nih.ar"
today=$(date +"%d-%m-%Y")
file="$1"

if [[ "${file##*.}" == "py" ]]; then
    cbang="#!/usr/bin/env python3"
else
    cbang="#!/bin/bash"
fi

heading() {
    cat <<EOF > "$file"
$cbang

#
#       ███╗   ██╗██╗██╗  ██╗ █████╗ ██████╗ ███████╗
#       ████╗  ██║██║██║  ██║██╔══██╗██╔══██╗██╔════╝
#       ██╔██╗ ██║██║███████║███████║██████╔╝███████╗
#       ██║╚██╗██║██║██╔══██║██╔══██║██╔══██╗╚════██║
#       ██║ ╚████║██║██║  ██║██║  ██║██║  ██║███████║
#       ╚═╝  ╚═══╝╚═╝╚═╝  ╚═╝╚═╝  ╚═╝╚═╝  ╚═╝╚══════╝
#       DRAFTED BY [$website] ON $today.
#       SOURCE [$file] LAST MODIFIED ON $today.
#
EOF
}

if [ -s "$file" ]; then
    line10=$(sed -n 10p "$file")

    if [[ "${line10:20:14}" != "$website" ]]; then
        # No header — prepend new header
        tmp="$(mktemp)"
        heading
        cat "$file" >> "$tmp"
        mv "$tmp" "$file"
    else
        # Header exists — just update the last modified line
        modline="#       SOURCE [$file] LAST MODIFIED ON $today."
        sed -i "11s|.*|$modline|" "$file"
    fi
else
    heading
fi

echo "" >> "$file"

Step 2: Add It to Your PATH

If ~/bin isn’t in your path yet, add this to your .bashrc or .zshrc:

export PATH="$HOME/bin:$PATH"

Then reload your shell:

source ~/.bashrc   # or ~/.zshrc

Now you can run it from anywhere:

headerize myscript.sh

Bonus: Add an Alias

alias h='headerize'

Then just:

h script.sh

Real World Usage

Whenever I start a new script or edit an existing one, I just run:

headerize filename.sh

If it's a new file → it adds a full header. If it's an old file → it updates the "Last Modified" line only. Creation date stays untouched. Clean and reliable.

That's It

I like building tools that do one job well. This little script has saved me countless tiny moments — and made my codebase feel more personal and professional.

Feel free to fork it, tweak it, or drop me a line if you improve it.

# Last updated on 2025-04-06.