Adding an EURion constellation to A4 PDF

eurionize.sh

#!/bin/bash

if [[ "$#" -ne 1 ]]; then
    echo "Usage: $0 filename" >&2
    exit 1
fi
if [[ ! -e "$1" ]]; then
    echo "$1 not found" >&2
    exit 1
fi

RAND=$(awk 'BEGIN {srand(); printf("%u", 1048576*rand());}')

gs -dSAFER -dBATCH -dNOPAUSE -sDEVICE=pdfwrite \
    -dPDFSETTINGS=/prepress -dEmbedAllFonts=true -dSubsetFonts=true \
    -dCompatibilityLevel=1.6 -dCompressPages=true -sOutputFile="${1%.*}_e.pdf" -_ "${1}" <<EOT
%!PS
% https://en.wikipedia.org/wiki/EURion_constellation
% http://www.bbc.com/future/story/20150624-the-secret-codes-of-british-banknotes
% this script presumes that your input has DIN/A4 paper dimensions (i.e. 595/842 points)

${RAND} srand
<< /BeginPage {
    pop
    gsave
    matrix defaultmatrix setmatrix
    1 1 20 {
        pop
        gsave
        rand 595 mod rand 842 mod translate
        rand 360 mod rotate
        2.8346 2.8346 scale
        0 0.1933 0.5714 0.0667 setcmykcolor
        .3 setlinewidth
        0 0 .4 0 360 arc stroke
        2.5 0 .4 0 360 arc stroke
        78 rotate 2.6 0 .4 0 360 arc stroke
        110 rotate 4.0 0 .4 0 360 arc stroke
        70 rotate 3.8 0 .4 0 360 arc stroke
        grestore
    } for
    grestore
} bind
>> setpagedevice
EOT