#!/usr/bin/ruby

# Author: Trizen

# Date: 02 April 2022

# https://github.com/trizen

# Encode data, using logarithms of integers.

# Example:

# Let's say we want to encode the bytes "abc" == [97, 98, 99]

# We try to find an integer n such that log(n) contains '097098099' after the decimal point.

# One such integer is 1453293358, which gives log(1453293358) = 21.097098099...

# Usage:

# sidef script.sf [input_file]

# The script generates a valid Sidef script as output, such that, when executed, it will produce the input data.

define (

PERL_CODE = false # true to generate Perl code

SLICE_SIZE = 1 # how many bytes to encode into an integer

)

func log_encode(bytes) {

var v = bytes.map { '%03d' % _ }.join

for n in (10 .. 99) {

var t = Num("#{n}.#{v}").exp.round

if (t.log.to_s.substr(3).begins_with(v)) {

return t

}

}

return nil

}

var text = File(ARGV[0] \\ __FILE__).read

var values = []

text.bytes.each_slice(SLICE_SIZE, {|*slice|

while (slice.len != SLICE_SIZE) {

slice += ' '.ord

}

values << log_encode(slice)

})

if (PERL_CODE) {

print %Q'print pack("C#{SLICE_SIZE}", unpack("x3(a3)#{SLICE_SIZE}", log)) for qw('

print values.join(' ')

say ')'

}

else {

print 'STDOUT.binmode(":raw");%n['

print values.join(' ')

say %Q'].each { pack("C#{SLICE_SIZE}", unpack("x3(a3)#{SLICE_SIZE}", .log)).print }'

}