The Base64 module provides for the encoding (#encode64) and decoding (#decode64) of binary data using a Base64 representation.
The following particular features are also provided:
encode into lines of a given length (#b64encode)
decode the special format specified in RFC2047 for the representation of email headers (decode_b)
A simple encoding and decoding.
require "base64" enc = Base64.encode64('Send reinforcements') # -> "U2VuZCByZWluZm9yY2VtZW50cw==\n" plain = Base64.decode64(enc) # -> "Send reinforcements"
The purpose of using base64 to encode data is that it translates any binary data into purely printable characters. It is specified in RFC 2045 (www.faqs.org/rfcs/rfc2045.html).
Prints the Base64 encoded version of
bin
(a String
) in lines of len
(default 60) characters.
require 'base64' data = "Now is the time for all good coders\nto learn Ruby" Base64.b64encode(data)
Generates:
Tm93IGlzIHRoZSB0aW1lIGZvciBhbGwgZ29vZCBjb2RlcnMKdG8gbGVhcm4g UnVieQ==
# File base64.rb, line 112 def b64encode(bin, len = 60) encode64(bin).scan(/.{1,#{len}}/) do print $&, "\n" end end
Returns the Base64-decoded version of str
.
require 'base64' str = 'VGhpcyBpcyBsaW5lIG9uZQpUaGlzIG' + 'lzIGxpbmUgdHdvClRoaXMgaXMgbGlu' + 'ZSB0aHJlZQpBbmQgc28gb24uLi4K' puts Base64.decode64(str)
Generates:
This is line one This is line two This is line three And so on...
# File base64.rb, line 58 def decode64(str) str.unpack("m")[0] end
Decodes text formatted using a subset of RFC2047 (the one used for mime-encoding mail headers).
Only supports an encoding type of 'b' (base 64), and only supports
the character sets ISO-2022-JP and SHIFT_JIS (so the only two encoded word
sequences recognized are =?ISO-2022-JP?B?...=
and
=?SHIFT_JIS?B?...=
). Recognition of these sequences is case
insensitive.
# File base64.rb, line 72 def decode_b(str) str.gsub!(/=\?ISO-2022-JP\?B\?([!->@-~]+)\?=/i) { decode64($1) } str = Kconv::toeuc(str) str.gsub!(/=\?SHIFT_JIS\?B\?([!->@-~]+)\?=/i) { decode64($1) } str = Kconv::toeuc(str) str.gsub!(/\n/, ' ') str.gsub!(/\0/, '') str end
Returns the Base64-encoded version of str
.
require 'base64' Base64.b64encode("Now is the time for all good coders\nto learn Ruby")
Generates:
Tm93IGlzIHRoZSB0aW1lIGZvciBhbGwgZ29vZCBjb2RlcnMKdG8gbGVhcm4g UnVieQ==
# File base64.rb, line 96 def encode64(bin) [bin].pack("m") end