When my wife said to me “Let me show you a t-shirt I saw…”, I wasn’t sure what to expect, but it definitely wasn’t an obfuscated bash script printed on the back designed to print a happy Easter egg message.

I’m not in the habit of clickbaity headlinesI’ve no idea at all how many views this site gets, but I’m willing to bet it’s not even double-digit humans per month. but I can see why subeditors have such fun with them. The title above is, strictly speaking, entirely accurate, but probably not what you think. The obfuscated code in question is actually an easter egg, it’s being supplied via Uniqlo stores on an excellent t-shirt designed by Akamai in support of their Peace for All campaign.

And it’s very cool! The front has a heart in curly braces:

While the back has a big alphanumeric block:

Is that … a shebang?!

My wife was right that I’d want to see it. Was that… a shebang?

Take a closer look at the text block:

Yes, a shebang! On a t-shirt sold in a high street store, no less. And it is clearly a base64 encoded Here string being fed to eval via base64 --decode.

Interesting. I told my wife "that’s basically how people ship viruses’ and bought it.

OCR was cumbersome

There was good news and bad news:

I ran OCR in a few ways: First, using the built-in OCR of the circle-to-search feature on Android, which is often very good. Second, by using Tesseract with a few options and tweaks. And third by running it through Claude. After diffing the three to look for mismatches and getting Claude to output a table of locations for quick scanning, it became trivial but time-consuimg to tidy up the remainder. The resulting string was:

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

The decoded script

After Base64 decoding, the resulting script is a welcoming and nicely commented Easter egg:

#!/bin/bash

# Congratulations! You found the easter egg! ❤️
# おめでとうございます！隠されたサプライズを見つけました！❤️

# Define the text to animate
text="♥PEACE♥FOR♥ALL♥PEACE♥FOR♥ALL♥PEACE♥FOR♥ALL♥PEACE♥FOR♥ALL♥PEACE♥FOR♥ALL♥"

# Get terminal dimensions
cols=$(tput cols)
lines=$(tput lines)

# Calculate the length of the text
text_length=${#text}

# Hide the cursor
tput civis

# Trap CTRL+C to show the cursor before exiting
trap "tput cnorm; exit" SIGINT

# Set frequency scaling factor
freq=0.2

# Infinite loop for continuous animation
for (( t=0; ; t+=1 )); do
    # Extract one character at a time
    char="${text:t % text_length:1}"
    
    # Calculate the angle in radians
    angle=$(echo "($t) * $freq" | bc -l)

    # Calculate the sine of the angle
    sine_value=$(echo "s($angle)" | bc -l)

    # Calculate x position using the sine value
    x=$(echo "($cols / 2) + ($cols / 4) * $sine_value" | bc -l)
    x=$(printf "%.0f" "$x")

    # Ensure x is within terminal bounds
    if (( x < 0 )); then x=0; fi
    if (( x >= cols )); then x=$((cols - 1)); fi

    # Calculate color gradient between 12 (cyan) and 208 (orange)
    color_start=12
    color_end=208
    color_range=$((color_end - color_start))
    color=$((color_start + (color_range * t / lines) % color_range))

    # Print the character with 256-color support
    echo -ne "\033[38;5;${color}m"$(tput cup $t $x)"$char\033[0m"

    # Line feed to move downward
    echo ""

done

The result is a continuous happy sine-wave loop of the campaign message, Peace for All:

Detail: The font choice

I guess Uniqlo is run through Windows though: one thing that struck me was the font, which I’m almost certain is ConsolasI was fortunate enough to correspond with the designer, Lucas de Groot, once in relation to a legal case in which someone had used one of his fonts to forge a document. He was very helpful and kind enough to confirm the necessary facts in writing, even though he owed nothing to us. , which I’m fond of. Note the very shallowly-slashed 0, the lack of serif on the 1 and the rounded curves of letters like BDyg and number 2. It’s striking because it’s primarily a Windows font, so not the sort of thing I’d expect to see calling Bash.

Linux, the language of the Internet

Akamai put out a press release about the shirt when it was released, which is another sort of interesting due to the blend of tech and marketing:

Design message

More than 25 years ago, Akamai helped make the internet we know today possible. This shirt’s design is a callback to those early days of life online. The light tan color is a reference to the “beige box” plastic casings that housed the early internet computers, and the heart on the front represents how the internet has been used for good all over the world. On the back of the T-shirt is real code. It’s a reference to Linux, the open-source language of the internet. This common language unites Akamai with the world’s top brands and the people they serve, as we work together toward a vision of a safer and more connected world.

Not the first

I deliberately didn’t search for spoilers at first, but I see that I am of course not the first person to get nerd-sniped by this. Wen Chuan Lee and that post also links to another (against which I’ve cross-checked my transcription above). I’m happy to carry on the chain.