ChRad

Change Radix. A command line utility to convert integer bases.

Arbitrarily large numbers are supported thanks to ruby's built-in support for bignums. Conversion to or from any positive integer fixed base system is supported.

Mixed-radix systems are not supported. For converting numbers in the factoradic (factorial base) system, use my factoradic gem or faster c utility.

Installation

Run:

gem install chrad

Usage

The command line utility

Options

Usage: chrad [options] -i <input_base> -o <output_base> <number> [...]

REQUIRED OPTIONS

  -i, --input=BASE         Interpret input strings integers in base <BASE>
  -o, --output=BASE        Print converted numbers as integers in base <BASE>

INPUT/OUTPUT FORMAT

      --input-list         Input values as delimiter separated lists
      --output-list        Output values as delimiter separated lists
  -l, --list               Both input and output values as delimiter separated lists
                           (Shorthand for using both --input-list and --output-list)
      --input-sep=CHAR     Use <CHAR> as the delimiter between places
                           in input vales when using --input-list mode
      --output-sep=CHAR    Use <CHAR> as the delimiter between places
                           in output vales when using --output-list mode
  -s, --separator=CHAR     Use <CHAR> as the delimiter between places in both
                           input and output list modes. (shorthand for using
                           both --input-separator=CHAR and --output-separator=CHAR)

DIGIT ALPHABET

      --input-digits=STR   Use the given <STR> as the set of chars to use
                           when interpreting input integers.
                           (Ignored when using--input-list mode.)
      --output-digits=STR  Use the given <STR> as the set of chars to use
                           when printing number in the output base.
                           (Ignored when using--input-list mode.)
  -d, --digits=STR         Use the given <STR> as the set of chars to use
                           for both input and output. (shorthand for using
                           both --input-digits=STR and --output-digits=STR)

      --list-named-digits  List the built-in named digit sets. These names
                           can be passed to any of --digits, --input-digits,
                           or --output-digits using the \"name:\" prefix.
                           (example: \"--digits=base64\")
  -h, --help               Show this help message
      --version            Show version

Examples

$ chrad -i 10 -o 16 255
ff

$ chrad -i 16 -o 2 c9
11001001

$ chrad -i 10 -o 64 --output-digits=name:base64 129633344153503
deadbeef

$ chrad -i 10 -o 64 --output-list 129633344153503
29,30,26,29,27,30,30,31

$ chrad -i 64 -o 64 --input-list --output-digits=name:base64 29,30,26,29,27,30,30,31
deadbeef

$ chrad -i 10 -o 4 --output-digits='♠♡♢♣' 4321

Input/Output

To represent a number in a given base, a set of digits must be available that is at least as large as that base. To support this, chrad allows you to provide a string of characters to use for input, output, or both (with --input-digits, --output-digits, and --digits respectively).

$ chrad -i 16 -o 3 --output-digits .-/ 5717063
/.-../---/...-/./

Built-in Digit Sets

Several commonly used sets of digits are built-in. To use a built-in set, use the name of the wet with the --digits options and a name: prefix.

$ chrad -i 16 -o 64 --output-digits=name:base64 dea

The built-in digit sets are:

$ chrad --list-named-digits
name:base62     ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789
name:base64     ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/
name:base64url  ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_
name:base32rfc  ABCDEFGHIJKLMNOPQRSTUVWXYZ234567
name:base32     0123456789abcdefghijklmnopqrstuv
name:base16     0123456789abcdef

The sets base16 and base32 are the common hexadecimal-style extension of the base 10 digits. The sets base64, base64url, and base32rfc are from RFC 3548.

List Mode

When converting numbers in very large bases, finding appropriate characters to use becomes difficult. To avoid this problem, use list mode. List mode can also make integration easier because it is a base-independent representation.

List mode can be enabled for input, output, or both with --input-list, --output-list, and -l/--list respectively. When list mode is enabled, numbers are represented as a comma (",") separated list of base 10 integers.

$ chrad -i 10 -o 64 --output-list  16772988
63,62,61,60

$ chrad -i 64 -o 16 --input-list 3,30,43,27,59,47
deadbeef

$ chrad -i 8 -o 16 --list 5,4,3,2,1
5,8,13,1

The comma separator can be changed to any character with the --input-sep, --output-sep, and -s/--separator options.

$ chrad -i 10 -o 64 --output-list --output-sep=: 16772988
63:62:61:60

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/pdkl95/chrad.

License

The gem is available as open source under the terms of the MIT License.