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Diffstat (limited to 'Master/tlpkg/tlperl/lib/MIME/Base64.pm')
-rw-r--r-- | Master/tlpkg/tlperl/lib/MIME/Base64.pm | 175 |
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diff --git a/Master/tlpkg/tlperl/lib/MIME/Base64.pm b/Master/tlpkg/tlperl/lib/MIME/Base64.pm new file mode 100644 index 00000000000..6c076d1b7c4 --- /dev/null +++ b/Master/tlpkg/tlperl/lib/MIME/Base64.pm @@ -0,0 +1,175 @@ +package MIME::Base64; + +use strict; +use vars qw(@ISA @EXPORT $VERSION); + +require Exporter; +@ISA = qw(Exporter); +@EXPORT = qw(encode_base64 decode_base64); + +$VERSION = '3.08'; + +require XSLoader; +XSLoader::load('MIME::Base64', $VERSION); + +*encode = \&encode_base64; +*decode = \&decode_base64; + +1; + +__END__ + +=head1 NAME + +MIME::Base64 - Encoding and decoding of base64 strings + +=head1 SYNOPSIS + + use MIME::Base64; + + $encoded = encode_base64('Aladdin:open sesame'); + $decoded = decode_base64($encoded); + +=head1 DESCRIPTION + +This module provides functions to encode and decode strings into and from the +base64 encoding specified in RFC 2045 - I<MIME (Multipurpose Internet +Mail Extensions)>. The base64 encoding is designed to represent +arbitrary sequences of octets in a form that need not be humanly +readable. A 65-character subset ([A-Za-z0-9+/=]) of US-ASCII is used, +enabling 6 bits to be represented per printable character. + +The following functions are provided: + +=over 4 + +=item encode_base64($str) + +=item encode_base64($str, $eol); + +Encode data by calling the encode_base64() function. The first +argument is the string to encode. The second argument is the +line-ending sequence to use. It is optional and defaults to "\n". The +returned encoded string is broken into lines of no more than 76 +characters each and it will end with $eol unless it is empty. Pass an +empty string as second argument if you do not want the encoded string +to be broken into lines. + +=item decode_base64($str) + +Decode a base64 string by calling the decode_base64() function. This +function takes a single argument which is the string to decode and +returns the decoded data. + +Any character not part of the 65-character base64 subset is +silently ignored. Characters occurring after a '=' padding character +are never decoded. + +If the length of the string to decode, after ignoring +non-base64 chars, is not a multiple of 4 or if padding occurs too early, +then a warning is generated if perl is running under C<-w>. + +=back + +If you prefer not to import these routines into your namespace, you can +call them as: + + use MIME::Base64 (); + $encoded = MIME::Base64::encode($decoded); + $decoded = MIME::Base64::decode($encoded); + +=head1 DIAGNOSTICS + +The following warnings can be generated if perl is invoked with the +C<-w> switch: + +=over 4 + +=item Premature end of base64 data + +The number of characters to decode is not a multiple of 4. Legal +base64 data should be padded with one or two "=" characters to make +its length a multiple of 4. The decoded result will be the same +whether the padding is present or not. + +=item Premature padding of base64 data + +The '=' padding character occurs as the first or second character +in a base64 quartet. + +=back + +The following exception can be raised: + +=over 4 + +=item Wide character in subroutine entry + +The string passed to encode_base64() contains characters with code +above 255. The base64 encoding is only defined for single-byte +characters. Use the Encode module to select the byte encoding you +want. + +=back + +=head1 EXAMPLES + +If you want to encode a large file, you should encode it in chunks +that are a multiple of 57 bytes. This ensures that the base64 lines +line up and that you do not end up with padding in the middle. 57 +bytes of data fills one complete base64 line (76 == 57*4/3): + + use MIME::Base64 qw(encode_base64); + + open(FILE, "/var/log/wtmp") or die "$!"; + while (read(FILE, $buf, 60*57)) { + print encode_base64($buf); + } + +or if you know you have enough memory + + use MIME::Base64 qw(encode_base64); + local($/) = undef; # slurp + print encode_base64(<STDIN>); + +The same approach as a command line: + + perl -MMIME::Base64 -0777 -ne 'print encode_base64($_)' <file + +Decoding does not need slurp mode if every line contains a multiple +of four base64 chars: + + perl -MMIME::Base64 -ne 'print decode_base64($_)' <file + +Perl v5.8 and better allow extended Unicode characters in strings. +Such strings cannot be encoded directly, as the base64 +encoding is only defined for single-byte characters. The solution is +to use the Encode module to select the byte encoding you want. For +example: + + use MIME::Base64 qw(encode_base64); + use Encode qw(encode); + + $encoded = encode_base64(encode("UTF-8", "\x{FFFF}\n")); + print $encoded; + +=head1 COPYRIGHT + +Copyright 1995-1999, 2001-2004 Gisle Aas. + +This library is free software; you can redistribute it and/or +modify it under the same terms as Perl itself. + +Distantly based on LWP::Base64 written by Martijn Koster +<m.koster@nexor.co.uk> and Joerg Reichelt <j.reichelt@nexor.co.uk> and +code posted to comp.lang.perl <3pd2lp$6gf@wsinti07.win.tue.nl> by Hans +Mulder <hansm@wsinti07.win.tue.nl> + +The XS implementation uses code from metamail. Copyright 1991 Bell +Communications Research, Inc. (Bellcore) + +=head1 SEE ALSO + +L<MIME::QuotedPrint> + +=cut |