#!/bin/env ruby
#
#############################################################
#
# author:  mathias gumz
# date  :  Don 26 Jun 2003 04:15:48 CEST
# file  :  rbdc
# about :  digits-converter
#
#############################################################
#
#
#
require 'getoptlong'

$DELIM= /:/
$JOIN=':'
$FORMAT= ''

MANPAGE= <<END

ABOUT

  rbdc is a ruby-digit-converter which converts digits from
  different bases into other bases

SYNOPSIS

  rbdc [-h] [-d delimiter] from2to number[delmiter]number

OPTIONS

  --help      -h    display help
  --delim     -d    delimiter (default ':')
  --join      -j    join (default ':')
  --format    -f    format for the output, see examples

  from              see BASES
  to                see BASES

BASES

  - b | bin | binary
  - o | oct | octal
  - d | dec | decimal
  - h | hex | hexadecimal

EXAMPLES

  - rbdc hex2dec 00:22:44:66:88:aa
  - rbdc bin2dec 10111

AUTHOR

  mathias gumz <gumz at cs.uni-magdeburg.de>

BUGS

  none atm

END


# returns the converted number
def conv(how, number)
  case how
  when /d.*2h.*/
    "%#{$FORMAT}x" % number
  when /h.*2d.*/
    "%#{$FORMAT}d" % number.to_s.hex
  when /d.*2o.*/
    "%#{$FORMAT}o" % number
  when /o.*2d.*/
    "%#{$FORMAT}d" % number.to_s.oct
  when /h.*2o.*/
    "%#{$FORMAT}o" % number.to_s.hex
  when /o.*2h.*/
    "%#{$FORMAT}x" % number.to_s.oct
  when /d.*2b.*/
    "%b" % number
  when /h.*2b.*/
    "%b" % number.to_s.hex
  when /o.*2b.*/
    "%b" % number.to_s.oct
  when /b.*2d.*/
    r= 0
    n= number.to_s.length - 1
    number.to_s.each_byte { |b| r+= (b-48) * (2**n); n-= 1 }
    return r
  when /b.*2h.*/
    "%#{$FORMAT}x" % conv("bin2dec", number)
  when /b.*2.*/
    "%#{$FORMAT}o" % conv("bin2dec", number)
  end
end

# main loop
begin
  opts= GetoptLong.new
  opts.set_options(
    [ "--help", "-h",   GetoptLong::NO_ARGUMENT ],
    [ "--delim", "-d",  GetoptLong::REQUIRED_ARGUMENT ],
    [ "--format", "-f", GetoptLong::REQUIRED_ARGUMENT ],
    [ "--join", "-j",   GetoptLong::REQUIRED_ARGUMENT ]
  )
  opts.each do |o,a|
    case o
    when /--help/
      puts MANPAGE
      exit 0
    when /--delim/
      $DELIM= a
    when /--join/
      $JOIN= a
    end
  end

  how = ARGV[0]
  r= ARGV[1].split($DELIM)

  0.upto(r.size-1) do |i|
    r[i]= conv(how, r[i])
  end
  puts r.join($JOIN)
end