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NAME

MIME::Base64 - Encoding and decoding of base64 strings
 

SYNOPSIS

 use MIME::Base64;

 $encoded = encode_base64('Aladdin:open sesame');
 $decoded = decode_base64($encoded);

DESCRIPTION

The following functions are provided:

encode_base64($str)

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.

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 "-w".

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);

DIAGNOSTICS

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.

Premature padding of base64 data

The '=' padding character occurs as the first or second character in a base64 quartet.

The following exception can be raised:

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.

EXAMPLES

   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;

COPYRIGHT

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)  

SEE ALSO

Index

NAME

SYNOPSIS

DESCRIPTION

DIAGNOSTICS

EXAMPLES

COPYRIGHT

SEE ALSO

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