Shows the hexadecimal representation of a given floating point value.

f2h.rb

# coding: utf-8
# ex.) $ ruby f2h.rb 1.0 -> 0000803f	00000000000000001000000000111111
require 'getoptlong'

def numeric?(str)
  true if Float(str) rescue false
end

$cmd_opts = GetoptLong.new(
  [ '-b', GetoptLong::NO_ARGUMENT ],
  [ '-d', GetoptLong::NO_ARGUMENT ],
  [ '-s', GetoptLong::NO_ARGUMENT ],
)

$opt_big = false
$opt_dbl = false
$opt_space = false

$cmd_opts.each do |opt, arg|
  case opt
  when '-b'; $opt_big = true
  when '-d'; $opt_dbl = true
  when '-s'; $opt_space = true
  end
end

if $0 == __FILE__
  values = ARGV.select {|arg| numeric?(arg) }
  values.each do |value|
    raw_str = [value.to_f].pack($opt_dbl ? 'D' : 'F').bytes
    raw_str.reverse! if $opt_big
    hex_str = raw_str.map {|byte| "%02x" % byte }.join($opt_space ? ' ' : '')
    print "#{hex_str}\t"
    bin_str = raw_str.map {|byte| "%08b" % byte }.join($opt_space ? ' ' : '')
    print "#{bin_str}\n"
  end
end