Graham Barr

NAME

Encode::Base32::Crockford - encode/decode numbers using Douglas Crockford's Base32 Encoding

VERSION

version 2.112991

DESCRIPTION

Douglas Crockford describes a Base32 Encoding at http://www.crockford.com/wrmg/base32.html. He says: "[Base32 Encoding is] a 32-symbol notation for expressing numbers in a form that can be conveniently and accurately transmitted between humans and computer systems."

This module provides methods to convert numbers to and from that notation.

SYNOPSIS

    use Encode::Base32::Crockford qw(:all); # import all methods

or

    use Encode::Base32::Crockford qw(base32_decode); # your choice of methods
    
    my $decoded = base32_decode_with_checksum("16JD");
    my $encoded = base32_encode_with_checksum(1234);

METHODS

base32_encode

    print base32_encode(1234); # prints "16J"

Encode a base 10 number. Will die on inappropriate input.

base32_encode_with_checksum

    print base32_encode_with_checksum(1234); # prints "16JD"

Encode a base 10 number with a checksum symbol appended. See the spec for a description of the checksum mechanism. Wraps the previous method so will also die on bad input.

base32_decode

    print base32_decode("16J"); # prints "1234"

    print base32_decode("IO", { mode => "warn"   }); # print "32" but warn
    print base32_decode("IO", { mode => "strict" }); # dies

Decode an encoded number into base 10. Will die on inappropriate input. The function is case-insensitive, and will strip any hyphens in the input (see normalize()). A hashref of options may be passed, with the only valid option being mode. If set to "warn", normalization will produce a warning; if set to "strict", requiring normalization will cause a fatal error.

base32_decode_with_checksum

    print base32_decode_with_checksum("16JD"); # prints "1234"

Decode an encoded number with a checksum into base 10. Will die if the checksum isn't correct, and die on inappropriate input. Takes the same mode option as base32_decode.

normalize

    my $string = "ix-Lb-Ko";
    my $clean = normalize($string);

    # $string is now '1X1BK0'.

The spec allows for certain symbols in encoded strings to be read as others, to avoid problems with misread strings. This function will perform the following conversions in the input string:

  • "i" or "I" to 1

  • "l" or "L" to 1

  • "o" or "O" to 0

It will also remove any instances of "-" in the input, which are permitted by the spec as chunking symbols to aid human reading of an encoded string, and uppercase the output.

AUTHOR

Graham Barr <gbarr@cpan.org>

CREDITS

The original module was written by Earle Martin <hex@cpan.org>

COPYRIGHT

This code is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

REPOSITORY

The git repository for this distribution is available at https://github.com/gbarr/Encode-Base32-Crockford