Convert-UUlib/UUlib.pm

package Convert::UUlib;

no warnings;
use strict;

use Carp;

require Exporter;
require DynaLoader;

our $VERSION = 1.62;

our @ISA = qw(Exporter DynaLoader);

our @_consts = qw(
        ACT_COPYING ACT_DECODING ACT_ENCODING ACT_IDLE ACT_SCANNING

        FILE_DECODED FILE_ERROR FILE_MISPART FILE_NOBEGIN FILE_NODATA
        FILE_NOEND FILE_OK FILE_READ FILE_TMPFILE

        MSG_ERROR MSG_FATAL MSG_MESSAGE MSG_NOTE MSG_PANIC MSG_WARNING

        OPT_RBUF OPT_WBUF
        OPT_BRACKPOL OPT_DEBUG OPT_DESPERATE OPT_DUMBNESS OPT_ENCEXT
        OPT_ERRNO OPT_FAST OPT_IGNMODE OPT_IGNREPLY OPT_OVERWRITE OPT_PREAMB
        OPT_PROGRESS OPT_SAVEPATH OPT_TINYB64 OPT_USETEXT OPT_VERBOSE
        OPT_VERSION OPT_REMOVE OPT_MOREMIME OPT_DOTDOT OPT_AUTOCHECK

        RET_CANCEL RET_CONT RET_EXISTS RET_ILLVAL RET_IOERR RET_NODATA
        RET_NOEND RET_NOMEM RET_OK RET_UNSUP

        B64_ENCODED BH_ENCODED PT_ENCODED QP_ENCODED
        XX_ENCODED UU_ENCODED YENC_ENCODED
);

our @_funcs = qw(
        Initialize CleanUp GetOption SetOption strerror SetMsgCallback
        SetBusyCallback SetFileCallback SetFNameFilter SetFileNameCallback
        FNameFilter LoadFile GetFileListItem GetFileList RenameFile DecodeToTemp
        RemoveTemp DecodeFile InfoFile Smerge QuickDecode EncodeMulti
        EncodePartial EncodeToStream EncodeToFile E_PrepSingle
        E_PrepPartial

        straction strencoding strmsglevel
);

our @EXPORT = @_consts;
our @EXPORT_OK = @_funcs;
our %EXPORT_TAGS = (all => [@_consts,@_funcs], constants => \@_consts);

bootstrap Convert::UUlib $VERSION;

Initialize();

# not when < 5.005_6x
# END { CleanUp() }

for (@_consts) {
   my $constant = constant($_);
   no strict 'refs';
   *$_ = sub () { $constant };
}

# action code -> string mapping
sub straction($) {
   return 'copying'     if $_[0] == &ACT_COPYING;
   return 'decoding'    if $_[0] == &ACT_DECODING;
   return 'encoding'    if $_[0] == &ACT_ENCODING;
   return 'idle'        if $_[0] == &ACT_IDLE;
   return 'scanning'    if $_[0] == &ACT_SCANNING;
   'unknown';
}

# encoding type -> string mapping
sub strencoding($) {
   return 'uuencode'            if $_[0] == &UU_ENCODED;
   return 'base64'              if $_[0] == &B64_ENCODED;
   return 'yenc'                if $_[0] == &YENC_ENCODED;
   return 'binhex'              if $_[0] == &BH_ENCODED;
   return 'plaintext'           if $_[0] == &PT_ENCODED;
   return 'quoted-printable'    if $_[0] == &QP_ENCODED;
   return 'xxencode'            if $_[0] == &XX_ENCODED;
   'unknown';
}

sub strmsglevel($) {
   return 'message'     if $_[0] == &MSG_MESSAGE;
   return 'note'        if $_[0] == &MSG_NOTE;
   return 'warning'     if $_[0] == &MSG_WARNING;
   return 'error'       if $_[0] == &MSG_ERROR;
   return 'panic'       if $_[0] == &MSG_PANIC;
   return 'fatal'       if $_[0] == &MSG_FATAL;
   'unknown';
}

1;
__END__

=head1 NAME

Convert::UUlib - Perl interface to the uulib library (a.k.a. uudeview/uuenview).

=head1 SYNOPSIS

 use Convert::UUlib ':all';
 
 # read all the files named on the commandline and decode them
 # into the CURRENT directory. See below for a longer example.
 LoadFile $_ for @ARGV;
 for my $uu (GetFileList) {
    if ($uu->state & FILE_OK) {
      $uu->decode;
      print $uu->filename, "\n";
    }
 }

=head1 DESCRIPTION

Read the file doc/library.pdf from the distribution for in-depth
information about the C-library used in this interface, and the rest of
this document and especially the non-trivial decoder program at the end.

=head1 EXPORTED CONSTANTS

=head2 Action code constants

  ACT_IDLE      we don't do anything
  ACT_SCANNING  scanning an input file
  ACT_DECODING  decoding into a temp file
  ACT_COPYING   copying temp to target
  ACT_ENCODING  encoding a file

=head2 Message severity levels

  MSG_MESSAGE   just a message, nothing important
  MSG_NOTE      something that should be noticed
  MSG_WARNING   important msg, processing continues
  MSG_ERROR     processing has been terminated
  MSG_FATAL     decoder cannot process further requests
  MSG_PANIC     recovery impossible, app must terminate

=head2 Options

  OPT_VERSION   version number MAJOR.MINORplPATCH (ro)
  OPT_FAST      assumes only one part per file
  OPT_DUMBNESS  switch off the program's intelligence
  OPT_BRACKPOL  give numbers in [] higher precendence
  OPT_VERBOSE   generate informative messages
  OPT_DESPERATE try to decode incomplete files
  OPT_IGNREPLY  ignore RE:plies (off by default)
  OPT_OVERWRITE whether it's OK to overwrite ex. files
  OPT_SAVEPATH  prefix to save-files on disk
  OPT_IGNMODE   ignore the original file mode
  OPT_DEBUG     print messages with FILE/LINE info
  OPT_ERRNO     get last error code for RET_IOERR (ro)
  OPT_PROGRESS  retrieve progress information
  OPT_USETEXT   handle text messages
  OPT_PREAMB    handle Mime preambles/epilogues
  OPT_TINYB64   detect short B64 outside of Mime
  OPT_ENCEXT    extension for single-part encoded files
  OPT_REMOVE    remove input files after decoding (dangerous)
  OPT_MOREMIME  strict MIME adherence
  OPT_DOTDOT    ".."-unescaping has not yet been done on input files
  OPT_RBUF      set default read I/O buffer size in bytes
  OPT_WBUF      set default write I/O buffer size in bytes
  OPT_AUTOCHECK automatically check file list after every loadfile

=head2 Result/Error codes

  RET_OK        everything went fine
  RET_IOERR     I/O Error - examine errno
  RET_NOMEM     not enough memory
  RET_ILLVAL    illegal value for operation
  RET_NODATA    decoder didn't find any data
  RET_NOEND     encoded data wasn't ended properly
  RET_UNSUP     unsupported function (encoding)
  RET_EXISTS    file exists (decoding)
  RET_CONT      continue -- special from ScanPart
  RET_CANCEL    operation canceled

=head2 File States

 This code is zero, i.e. "false":

  UUFILE_READ   Read in, but not further processed

 The following state codes are or'ed together:

  FILE_MISPART  Missing Part(s) detected
  FILE_NOBEGIN  No 'begin' found
  FILE_NOEND    No 'end' found
  FILE_NODATA   File does not contain valid uudata
  FILE_OK       All Parts found, ready to decode
  FILE_ERROR    Error while decoding
  FILE_DECODED  Successfully decoded
  FILE_TMPFILE  Temporary decoded file exists

=head2 Encoding types

  UU_ENCODED    UUencoded data
  B64_ENCODED   Mime-Base64 data
  XX_ENCODED    XXencoded data
  BH_ENCODED    Binhex encoded
  PT_ENCODED    Plain-Text encoded (MIME)
  QP_ENCODED    Quoted-Printable (MIME)
  YENC_ENCODED  yEnc encoded (non-MIME)

=head1 EXPORTED FUNCTIONS

=head2 Initializing and cleanup

Initialize is automatically called when the module is loaded and allocates
quite a small amount of memory for todays machines ;) CleanUp releases that
again.

On my machine, a fairly complete decode with DBI backend needs about 10MB
RSS to decode 20000 files.

=over

=item Initialize

Not normally necessary, (re-)initializes the library.

=item CleanUp

Not normally necessary, could be called at the end to release memory
before starting a new decoding round.

=back

=head2 Setting and querying options

=over

=item $option = GetOption OPT_xxx

=item SetOption OPT_xxx, opt-value

=back

See the C<OPT_xxx> constants above to see which options exist.

=head2 Setting various callbacks

=over

=item SetMsgCallback [callback-function]

=item SetBusyCallback [callback-function]

=item SetFileCallback [callback-function]

=item SetFNameFilter [callback-function]

=back

=head2 Call the currently selected FNameFilter

=over

=item $file = FNameFilter $file

=back

=head2 Loading sourcefiles, optionally fuzzy merge and start decoding

=over

=item ($retval, $count) = LoadFile $fname, [$id, [$delflag, [$partno]]]

Load the given file and scan it for encoded contents. Optionally tag it
with the given id, and if C<$delflag> is true, delete the file after it
is no longer necessary. If you are certain of the part number, you can
specify it as the last argument.

A better (usually faster) way of doing this is using the C<SetFNameFilter>
functionality.

=item $retval = Smerge $pass

If you are desperate, try to call C<Smerge> with increasing C<$pass>
values, beginning at C<0>, to try to merge parts that usually would not
have been merged.

Most probably this will result in garbled files, so never do this by
default, except:

If the C<OPT_AUTOCHECK> option has been disabled (by default it is
enabled) to speed up file loading, then you I<have> to call C<Smerge -1>
after loading all files as an additional pre-pass (which is normally done
by C<LoadFile>).

=item $item = GetFileListItem $item_number

Return the C<$item> structure for the C<$item_number>'th found file, or
C<undef> of no file with that number exists.

The first file has number C<0>, and the series has no holes, so you can
iterate over all files by starting with zero and incrementing until you
hit C<undef>.

This function has to walk the linear list of fils on each access, so
if you want to iterate over all items, it is usually faster to use
C<GetFileList>.

=item @items = GetFileList

Similar to C<GetFileListItem>, but returns all files in one go.

=back

=head2 Decoding files

=over

=item $retval = $item->rename ($newname)

Change the ondisk filename where the decoded file will be saved.

=item $retval = $item->decode_temp

Decode the file into a temporary location, use C<< $item->infile >> to
retrieve the temporary filename.

=item $retval = $item->remove_temp

Remove the temporarily decoded file again.

=item $retval = $item->decode ([$target_path])

Decode the file to its destination, or the given target path.

=item $retval = $item->info (callback-function)

=back

=head2 Querying (and setting) item attributes

=over

=item $state    = $item->state

=item $mode     = $item->mode ([newmode])

=item $uudet    = $item->uudet

=item $size     = $item->size

=item $filename = $item->filename ([newfilename})

=item $subfname = $item->subfname

=item $mimeid   = $item->mimeid

=item $mimetype = $item->mimetype

=item $binfile  = $item->binfile

=back

=head2 Information about source parts

=over

=item $parts = $item->parts

Return information about all parts (source files) used to decode the file
as a list of hashrefs with the following structure:

 {
   partno   => <integer describing the part number, starting with 1>,
   # the following member sonly exist when they contain useful information
   sfname   => <local pathname of the file where this part is from>,
   filename => <the ondisk filename of the decoded file>,
   subfname => <used to cluster postings, possibly the posting filename>,
   subject  => <the subject of the posting/mail>,
   origin   => <the possible source (From) address>,
   mimetype => <the possible mimetype of the decoded file>,
   mimeid   => <the id part of the Content-Type>,
 }

Usually you are interested mostly the C<sfname> and possibly the C<partno>
and C<filename> members.

=back

=head2 Functions below are not documented and not very well tested - feedback welcome

  QuickDecode
  EncodeMulti
  EncodePartial
  EncodeToStream
  EncodeToFile
  E_PrepSingle
  E_PrepPartial

=head2 EXTENSION FUNCTIONS

Functions found in this module but not documented in the uulib documentation:

=over

=item $msg = straction ACT_xxx

Return a human readable string representing the given action code.

=item $msg = strerror RET_xxx

Return a human readable string representing the given error code.

=item $str = strencoding xxx_ENCODED

Return the name of the encoding type as a string.

=item $str = strmsglevel MSG_xxx

Returns the message level as a string.

=item SetFileNameCallback $cb

Sets (or queries) the FileNameCallback, which is called whenever the
decoding library can't find a filename and wants to extract a filename
from the subject line of a posting. The callback will be called with
two arguments, the subject line and the current candidate for the
filename. The latter argument can be C<undef>, which means that no
filename could be found (and likely no one exists, so it is safe to also
return C<undef> in this case). If it doesn't return anything (not even
C<undef>!), then nothing happens, so this is a no-op callback:

   sub cb {
      return ();
   }

If it returns C<undef>, then this indicates that no filename could be
found. In all other cases, the return value is taken to be the filename.

This is a slightly more useful callback:

  sub cb {
     return unless $_[1]; # skip "Re:"-plies et al.
     my ($subject, $filename) = @_;
     # if we find some *.rar, take it
     return $1 if $subject =~ /(\w+\.rar)/;
     # otherwise just pass what we have
     return ();
  }

=back

=head1 LARGE EXAMPLE DECODER

This is the file C<example-decoder> from the distribution, put here
instead of more thorough documentation.

   #!/usr/bin/perl

   # decode all the files in the directory uusrc/ and copy
   # the resulting files to uudst/

   use Convert::UUlib ':all';

   sub namefilter {
      my ($path) = @_;

      $path=~s/^.*[\/\\]//;

      $path
   }

   sub busycb {
      my ($action, $curfile, $partno, $numparts, $percent, $fsize) = @_;
      $_[0]=straction($action);
      print "busy_callback(", (join ",",@_), ")\n";
      0
   }

   SetOption OPT_RBUF, 128*1024;
   SetOption OPT_WBUF, 1024*1024;
   SetOption OPT_IGNMODE, 1;
   SetOption OPT_IGNMODE, 1;
   SetOption OPT_VERBOSE, 1;

   # show the three ways you can set callback functions. I normally
   # prefer the one with the sub inplace.
   SetFNameFilter \&namefilter;

   SetBusyCallback "busycb", 333;

   SetMsgCallback sub {
      my ($msg, $level) = @_;
      print uc strmsglevel $_[1], ": $msg\n";
   };

   # the following non-trivial FileNameCallback takes care
   # of some subject lines not detected properly by uulib:
   SetFileNameCallback sub {
      return unless $_[1]; # skip "Re:"-plies et al.
      local $_ = $_[0];

      # the following rules are rather effective on some newsgroups,
      # like alt.binaries.games.anime, where non-mime, uuencoded data
      # is very common

      # if we find some *.rar, take it as the filename
      return $1 if /(\S{3,}\.(?:[rstuvwxyz]\d\d|rar))\s/i;

      # one common subject format
      return $1 if /- "(.{2,}?\..+?)" (?:yenc )?\(\d+\/\d+\)/i;

      # - filename.par (04/55)
      return $1 if /- "?(\S{3,}\.\S+?)"? (?:yenc )?\(\d+\/\d+\)/i;

      # - (xxx) No. 1 sayuri81.jpg 756565 bytes
      # - (20 files) No.17 Roseanne.jpg [2/2]
      return $1 if /No\.[ 0-9]+ (\S+\....) (?:\d+ bytes )?\[/;

      # try to detect some common forms of filenames
      return $1 if /([a-z0-9_\-+.]{3,}\.[a-z]{3,4}(?:.\d+))/i;

      # otherwise just pass what we have
      ()
   };

   # now read all files in the directory uusrc/*
   for (<uusrc/*>) {
      my ($retval, $count) = LoadFile ($_, $_, 1);
      print "file($_), status(", strerror $retval, ") parts($count)\n";
   }

   SetOption OPT_SAVEPATH, "uudst/";

   # now wade through all files and their source parts
   for my $uu (GetFileList) {
      print "file ", $uu->filename, "\n";
      print " state ", $uu->state, "\n";
      print " mode ", $uu->mode, "\n";
      print " uudet ", strencoding $uu->uudet, "\n";
      print " size ", $uu->size, "\n";
      print " subfname ", $uu->subfname, "\n";
      print " mimeid ", $uu->mimeid, "\n";
      print " mimetype ", $uu->mimetype, "\n";

      # print additional info about all parts
      print " parts";
      for ($uu->parts) {
         for my $k (sort keys %$_) {
            print " $k=$_->{$k}";
         }
         print "\n";
      }

      $uu->remove_temp;

      if (my $err = $uu->decode) {
         print " ERROR ", strerror $err, "\n";
      } else {
         print " successfully saved as uudst/", $uu->filename, "\n";
      }
   }

   print "cleanup...\n";

   CleanUp;

=head1 PERLMULTICORE SUPPORT

This module supports the perlmulticore standard (see
L<http://perlmulticore.schmorp.de/> for more info) for the following
functions - generally these are functions accessing the disk and/or using
considerable CPU time:

   LoadFile
   $item->decode
   $item->decode_temp
   $item->remove_temp
   $item->info

The perl interpreter will be reacquired/released on every callback
invocation, so for performance reasons, callbacks should be avoided if
that is costly.

Future versions might enable multicore support for more functions.

=head1 BUGS AND LIMITATIONS

The original uulib library this module uses was written at a time where
main memory of measured in megabytes and buffer overflows as a security
thign didn't exist. While a lot of security fixes have been applied over
the years (includign some defense in depth mechanism that can shield
against a lot of as-of-yet undetected bugs), using this library for
security purposes requires care.

Likewise, file sizes when the uulib library was written were tiny compared
to today, so do not expect this library to handle files larger than 2GB.

=head1 AUTHOR

Marc Lehmann <schmorp@schmorp.de>, the original uulib library was written
by Frank Pilhofer <fp@informatik.uni-frankfurt.de>, and later heavily
bugfixed by Marc Lehmann.

=head1 SEE ALSO

perl(1), uudeview homepage at L<http://www.fpx.de/fp/Software/UUDeview/>.

=cut

Revision:	1.47
Committed:	Fri Feb 28 16:57:25 2020 UTC (4 years, 2 months ago) by root
Branch:	MAIN
Changes since 1.46:	+26 -23 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	package Convert::UUlib;
2
3	root	1.28	no warnings;
4			use strict;
5
6	root	1.1	use Carp;
7
8			require Exporter;
9			require DynaLoader;
10
11	root	1.44	our $VERSION = 1.62;
12	root	1.1
13	root	1.28	our @ISA = qw(Exporter DynaLoader);
14	root	1.1
15	root	1.28	our @_consts = qw(
16	root	1.1	ACT_COPYING ACT_DECODING ACT_ENCODING ACT_IDLE ACT_SCANNING
17
18			FILE_DECODED FILE_ERROR FILE_MISPART FILE_NOBEGIN FILE_NODATA
19			FILE_NOEND FILE_OK FILE_READ FILE_TMPFILE
20
21			MSG_ERROR MSG_FATAL MSG_MESSAGE MSG_NOTE MSG_PANIC MSG_WARNING
22
23	root	1.25	OPT_RBUF OPT_WBUF
24	root	1.1	OPT_BRACKPOL OPT_DEBUG OPT_DESPERATE OPT_DUMBNESS OPT_ENCEXT
25			OPT_ERRNO OPT_FAST OPT_IGNMODE OPT_IGNREPLY OPT_OVERWRITE OPT_PREAMB
26			OPT_PROGRESS OPT_SAVEPATH OPT_TINYB64 OPT_USETEXT OPT_VERBOSE
27	root	1.34	OPT_VERSION OPT_REMOVE OPT_MOREMIME OPT_DOTDOT OPT_AUTOCHECK
28	root	1.1
29			RET_CANCEL RET_CONT RET_EXISTS RET_ILLVAL RET_IOERR RET_NODATA
30			RET_NOEND RET_NOMEM RET_OK RET_UNSUP
31
32	root	1.11	B64_ENCODED BH_ENCODED PT_ENCODED QP_ENCODED
33	root	1.5	XX_ENCODED UU_ENCODED YENC_ENCODED
34	root	1.1	);
35
36	root	1.28	our @_funcs = qw(
37	root	1.6	Initialize CleanUp GetOption SetOption strerror SetMsgCallback
38			SetBusyCallback SetFileCallback SetFNameFilter SetFileNameCallback
39	root	1.47	FNameFilter LoadFile GetFileListItem GetFileList RenameFile DecodeToTemp
40	root	1.6	RemoveTemp DecodeFile InfoFile Smerge QuickDecode EncodeMulti
41			EncodePartial EncodeToStream EncodeToFile E_PrepSingle
42	root	1.35	E_PrepPartial
43	root	1.1
44			straction strencoding strmsglevel
45			);
46
47	root	1.28	our @EXPORT = @_consts;
48			our @EXPORT_OK = @_funcs;
49			our %EXPORT_TAGS = (all => [@_consts,@_funcs], constants => \@_consts);
50	root	1.1
51			bootstrap Convert::UUlib $VERSION;
52
53			Initialize();
54
55			# not when < 5.005_6x
56			# END { CleanUp() }
57
58			for (@_consts) {
59			my $constant = constant($_);
60	root	1.28	no strict 'refs';
61	root	1.1	*$_ = sub () { $constant };
62			}
63
64			# action code -> string mapping
65			sub straction($) {
66			return 'copying' if $_[0] == &ACT_COPYING;
67			return 'decoding' if $_[0] == &ACT_DECODING;
68			return 'encoding' if $_[0] == &ACT_ENCODING;
69			return 'idle' if $_[0] == &ACT_IDLE;
70			return 'scanning' if $_[0] == &ACT_SCANNING;
71	root	1.5	'unknown';
72	root	1.1	}
73
74			# encoding type -> string mapping
75			sub strencoding($) {
76	root	1.5	return 'uuencode' if $_[0] == &UU_ENCODED;
77	root	1.11	return 'base64' if $_[0] == &B64_ENCODED;
78	root	1.5	return 'yenc' if $_[0] == &YENC_ENCODED;
79	root	1.1	return 'binhex' if $_[0] == &BH_ENCODED;
80			return 'plaintext' if $_[0] == &PT_ENCODED;
81			return 'quoted-printable' if $_[0] == &QP_ENCODED;
82			return 'xxencode' if $_[0] == &XX_ENCODED;
83	root	1.5	'unknown';
84	root	1.1	}
85
86			sub strmsglevel($) {
87			return 'message' if $_[0] == &MSG_MESSAGE;
88			return 'note' if $_[0] == &MSG_NOTE;
89			return 'warning' if $_[0] == &MSG_WARNING;
90			return 'error' if $_[0] == &MSG_ERROR;
91			return 'panic' if $_[0] == &MSG_PANIC;
92			return 'fatal' if $_[0] == &MSG_FATAL;
93	root	1.5	'unknown';
94	root	1.1	}
95
96			1;
97			__END__
98
99			=head1 NAME
100
101			Convert::UUlib - Perl interface to the uulib library (a.k.a. uudeview/uuenview).
102
103			=head1 SYNOPSIS
104
105			use Convert::UUlib ':all';
106
107	root	1.11	# read all the files named on the commandline and decode them
108	root	1.13	# into the CURRENT directory. See below for a longer example.
109			LoadFile $_ for @ARGV;
110	root	1.47	for my $uu (GetFileList) {
111	root	1.13	if ($uu->state & FILE_OK) {
112			$uu->decode;
113			print $uu->filename, "\n";
114			}
115	root	1.1	}
116
117	root	1.11	=head1 DESCRIPTION
118	root	1.1
119	root	1.11	Read the file doc/library.pdf from the distribution for in-depth
120			information about the C-library used in this interface, and the rest of
121			this document and especially the non-trivial decoder program at the end.
122
123			=head1 EXPORTED CONSTANTS
124
125			=head2 Action code constants
126
127			ACT_IDLE we don't do anything
128			ACT_SCANNING scanning an input file
129			ACT_DECODING decoding into a temp file
130			ACT_COPYING copying temp to target
131			ACT_ENCODING encoding a file
132
133			=head2 Message severity levels
134
135			MSG_MESSAGE just a message, nothing important
136			MSG_NOTE something that should be noticed
137			MSG_WARNING important msg, processing continues
138			MSG_ERROR processing has been terminated
139			MSG_FATAL decoder cannot process further requests
140			MSG_PANIC recovery impossible, app must terminate
141
142			=head2 Options
143
144			OPT_VERSION version number MAJOR.MINORplPATCH (ro)
145			OPT_FAST assumes only one part per file
146			OPT_DUMBNESS switch off the program's intelligence
147			OPT_BRACKPOL give numbers in [] higher precendence
148			OPT_VERBOSE generate informative messages
149			OPT_DESPERATE try to decode incomplete files
150			OPT_IGNREPLY ignore RE:plies (off by default)
151			OPT_OVERWRITE whether it's OK to overwrite ex. files
152			OPT_SAVEPATH prefix to save-files on disk
153			OPT_IGNMODE ignore the original file mode
154			OPT_DEBUG print messages with FILE/LINE info
155			OPT_ERRNO get last error code for RET_IOERR (ro)
156			OPT_PROGRESS retrieve progress information
157			OPT_USETEXT handle text messages
158			OPT_PREAMB handle Mime preambles/epilogues
159			OPT_TINYB64 detect short B64 outside of Mime
160			OPT_ENCEXT extension for single-part encoded files
161	root	1.14	OPT_REMOVE remove input files after decoding (dangerous)
162	root	1.11	OPT_MOREMIME strict MIME adherence
163	root	1.15	OPT_DOTDOT ".."-unescaping has not yet been done on input files
164	root	1.35	OPT_RBUF set default read I/O buffer size in bytes
165			OPT_WBUF set default write I/O buffer size in bytes
166			OPT_AUTOCHECK automatically check file list after every loadfile
167	root	1.11
168			=head2 Result/Error codes
169
170			RET_OK everything went fine
171			RET_IOERR I/O Error - examine errno
172			RET_NOMEM not enough memory
173			RET_ILLVAL illegal value for operation
174			RET_NODATA decoder didn't find any data
175			RET_NOEND encoded data wasn't ended properly
176			RET_UNSUP unsupported function (encoding)
177			RET_EXISTS file exists (decoding)
178			RET_CONT continue -- special from ScanPart
179			RET_CANCEL operation canceled
180
181			=head2 File States
182
183			This code is zero, i.e. "false":
184
185			UUFILE_READ Read in, but not further processed
186
187	root	1.13	The following state codes are or'ed together:
188	root	1.11
189			FILE_MISPART Missing Part(s) detected
190			FILE_NOBEGIN No 'begin' found
191			FILE_NOEND No 'end' found
192			FILE_NODATA File does not contain valid uudata
193			FILE_OK All Parts found, ready to decode
194			FILE_ERROR Error while decoding
195			FILE_DECODED Successfully decoded
196			FILE_TMPFILE Temporary decoded file exists
197
198			=head2 Encoding types
199
200			UU_ENCODED UUencoded data
201			B64_ENCODED Mime-Base64 data
202			XX_ENCODED XXencoded data
203			BH_ENCODED Binhex encoded
204			PT_ENCODED Plain-Text encoded (MIME)
205			QP_ENCODED Quoted-Printable (MIME)
206			YENC_ENCODED yEnc encoded (non-MIME)
207	root	1.1
208	root	1.11	=head1 EXPORTED FUNCTIONS
209	root	1.1
210	root	1.11	=head2 Initializing and cleanup
211	root	1.1
212	root	1.11	Initialize is automatically called when the module is loaded and allocates
213	root	1.13	quite a small amount of memory for todays machines ;) CleanUp releases that
214			again.
215	root	1.14
216			On my machine, a fairly complete decode with DBI backend needs about 10MB
217			RSS to decode 20000 files.
218	root	1.1
219	root	1.46	=over
220	root	1.13
221			=item Initialize
222
223			Not normally necessary, (re-)initializes the library.
224
225			=item CleanUp
226
227			Not normally necessary, could be called at the end to release memory
228			before starting a new decoding round.
229
230			=back
231	root	1.1
232	root	1.11	=head2 Setting and querying options
233	root	1.1
234	root	1.46	=over
235	root	1.13
236			=item $option = GetOption OPT_xxx
237
238			=item SetOption OPT_xxx, opt-value
239
240			=back
241
242			See the C<OPT_xxx> constants above to see which options exist.
243	root	1.1
244	root	1.11	=head2 Setting various callbacks
245	root	1.1
246	root	1.46	=over
247	root	1.13
248			=item SetMsgCallback [callback-function]
249
250			=item SetBusyCallback [callback-function]
251
252			=item SetFileCallback [callback-function]
253
254			=item SetFNameFilter [callback-function]
255
256			=back
257	root	1.1
258	root	1.11	=head2 Call the currently selected FNameFilter
259	root	1.1
260	root	1.46	=over
261	root	1.13
262			=item $file = FNameFilter $file
263
264			=back
265	root	1.1
266	root	1.11	=head2 Loading sourcefiles, optionally fuzzy merge and start decoding
267	root	1.1
268	root	1.46	=over
269	root	1.13
270	root	1.16	=item ($retval, $count) = LoadFile $fname, [$id, [$delflag, [$partno]]]
271	root	1.13
272			Load the given file and scan it for encoded contents. Optionally tag it
273	root	1.16	with the given id, and if C<$delflag> is true, delete the file after it
274	root	1.18	is no longer necessary. If you are certain of the part number, you can
275			specify it as the last argument.
276	root	1.16
277			A better (usually faster) way of doing this is using the C<SetFNameFilter>
278			functionality.
279	root	1.13
280			=item $retval = Smerge $pass
281
282			If you are desperate, try to call C<Smerge> with increasing C<$pass>
283			values, beginning at C<0>, to try to merge parts that usually would not
284			have been merged.
285
286			Most probably this will result in garbled files, so never do this by
287	root	1.35	default, except:
288
289			If the C<OPT_AUTOCHECK> option has been disabled (by default it is
290			enabled) to speed up file loading, then you I<have> to call C<Smerge -1>
291			after loading all files as an additional pre-pass (which is normally done
292			by C<LoadFile>).
293	root	1.13
294			=item $item = GetFileListItem $item_number
295
296			Return the C<$item> structure for the C<$item_number>'th found file, or
297			C<undef> of no file with that number exists.
298
299			The first file has number C<0>, and the series has no holes, so you can
300			iterate over all files by starting with zero and incrementing until you
301			hit C<undef>.
302
303	root	1.47	This function has to walk the linear list of fils on each access, so
304			if you want to iterate over all items, it is usually faster to use
305			C<GetFileList>.
306
307			=item @items = GetFileList
308
309			Similar to C<GetFileListItem>, but returns all files in one go.
310
311	root	1.13	=back
312
313			=head2 Decoding files
314
315	root	1.46	=over
316	root	1.13
317	root	1.46	=item $retval = $item->rename ($newname)
318	root	1.13
319			Change the ondisk filename where the decoded file will be saved.
320
321			=item $retval = $item->decode_temp
322
323			Decode the file into a temporary location, use C<< $item->infile >> to
324			retrieve the temporary filename.
325
326			=item $retval = $item->remove_temp
327
328			Remove the temporarily decoded file again.
329
330	root	1.46	=item $retval = $item->decode ([$target_path])
331	root	1.13
332	root	1.46	Decode the file to its destination, or the given target path.
333	root	1.13
334	root	1.46	=item $retval = $item->info (callback-function)
335	root	1.13
336			=back
337	root	1.1
338	root	1.11	=head2 Querying (and setting) item attributes
339	root	1.1
340	root	1.46	=over
341	root	1.13
342			=item $state = $item->state
343
344	root	1.46	=item $mode = $item->mode ([newmode])
345	root	1.13
346			=item $uudet = $item->uudet
347
348			=item $size = $item->size
349
350	root	1.46	=item $filename = $item->filename ([newfilename})
351	root	1.13
352			=item $subfname = $item->subfname
353
354			=item $mimeid = $item->mimeid
355
356			=item $mimetype = $item->mimetype
357
358			=item $binfile = $item->binfile
359
360			=back
361
362			=head2 Information about source parts
363
364	root	1.46	=over
365	root	1.13
366			=item $parts = $item->parts
367
368			Return information about all parts (source files) used to decode the file
369			as a list of hashrefs with the following structure:
370
371			{
372			partno => <integer describing the part number, starting with 1>,
373			# the following member sonly exist when they contain useful information
374			sfname => <local pathname of the file where this part is from>,
375			filename => <the ondisk filename of the decoded file>,
376			subfname => <used to cluster postings, possibly the posting filename>,
377			subject => <the subject of the posting/mail>,
378			origin => <the possible source (From) address>,
379			mimetype => <the possible mimetype of the decoded file>,
380			mimeid => <the id part of the Content-Type>,
381			}
382	root	1.1
383	root	1.13	Usually you are interested mostly the C<sfname> and possibly the C<partno>
384			and C<filename> members.
385	root	1.1
386	root	1.13	=back
387	root	1.1
388	root	1.46	=head2 Functions below are not documented and not very well tested - feedback welcome
389	root	1.1
390	root	1.11	QuickDecode
391			EncodeMulti
392			EncodePartial
393			EncodeToStream
394			EncodeToFile
395			E_PrepSingle
396			E_PrepPartial
397	root	1.6
398			=head2 EXTENSION FUNCTIONS
399
400			Functions found in this module but not documented in the uulib documentation:
401
402	root	1.46	=over
403	root	1.6
404	root	1.11	=item $msg = straction ACT_xxx
405
406			Return a human readable string representing the given action code.
407
408			=item $msg = strerror RET_xxx
409
410			Return a human readable string representing the given error code.
411
412			=item $str = strencoding xxx_ENCODED
413
414			Return the name of the encoding type as a string.
415
416			=item $str = strmsglevel MSG_xxx
417
418			Returns the message level as a string.
419
420	root	1.6	=item SetFileNameCallback $cb
421
422			Sets (or queries) the FileNameCallback, which is called whenever the
423			decoding library can't find a filename and wants to extract a filename
424			from the subject line of a posting. The callback will be called with
425			two arguments, the subject line and the current candidate for the
426			filename. The latter argument can be C<undef>, which means that no
427			filename could be found (and likely no one exists, so it is safe to also
428			return C<undef> in this case). If it doesn't return anything (not even
429			C<undef>!), then nothing happens, so this is a no-op callback:
430
431			sub cb {
432			return ();
433			}
434
435			If it returns C<undef>, then this indicates that no filename could be
436			found. In all other cases, the return value is taken to be the filename.
437
438			This is a slightly more useful callback:
439
440			sub cb {
441			return unless $_[1]; # skip "Re:"-plies et al.
442			my ($subject, $filename) = @_;
443			# if we find some *.rar, take it
444			return $1 if $subject =~ /(\w+\.rar)/;
445			# otherwise just pass what we have
446			return ();
447			}
448
449			=back
450	root	1.1
451	root	1.11	=head1 LARGE EXAMPLE DECODER
452
453			This is the file C<example-decoder> from the distribution, put here
454			instead of more thorough documentation.
455
456	root	1.32	#!/usr/bin/perl
457	root	1.11
458	root	1.32	# decode all the files in the directory uusrc/ and copy
459			# the resulting files to uudst/
460	root	1.11
461	root	1.32	use Convert::UUlib ':all';
462	root	1.11
463	root	1.32	sub namefilter {
464			my ($path) = @_;
465	root	1.11
466	root	1.32	$path=~s/^.*[\/\\]//;
467	root	1.11
468	root	1.32	$path
469			}
470	root	1.11
471	root	1.32	sub busycb {
472			my ($action, $curfile, $partno, $numparts, $percent, $fsize) = @_;
473			$_[0]=straction($action);
474			print "busy_callback(", (join ",",@_), ")\n";
475			0
476			}
477	root	1.11
478	root	1.32	SetOption OPT_RBUF, 128*1024;
479			SetOption OPT_WBUF, 1024*1024;
480			SetOption OPT_IGNMODE, 1;
481			SetOption OPT_IGNMODE, 1;
482			SetOption OPT_VERBOSE, 1;
483
484			# show the three ways you can set callback functions. I normally
485			# prefer the one with the sub inplace.
486			SetFNameFilter \&namefilter;
487
488			SetBusyCallback "busycb", 333;
489
490			SetMsgCallback sub {
491			my ($msg, $level) = @_;
492			print uc strmsglevel $_[1], ": $msg\n";
493			};
494
495			# the following non-trivial FileNameCallback takes care
496			# of some subject lines not detected properly by uulib:
497			SetFileNameCallback sub {
498			return unless $_[1]; # skip "Re:"-plies et al.
499			local $_ = $_[0];
500
501			# the following rules are rather effective on some newsgroups,
502			# like alt.binaries.games.anime, where non-mime, uuencoded data
503			# is very common
504
505			# if we find some *.rar, take it as the filename
506			return $1 if /(\S{3,}\.(?:[rstuvwxyz]\d\d\|rar))\s/i;
507
508			# one common subject format
509			return $1 if /- "(.{2,}?\..+?)" (?:yenc )?\(\d+\/\d+\)/i;
510
511			# - filename.par (04/55)
512			return $1 if /- "?(\S{3,}\.\S+?)"? (?:yenc )?\(\d+\/\d+\)/i;
513
514			# - (xxx) No. 1 sayuri81.jpg 756565 bytes
515			# - (20 files) No.17 Roseanne.jpg [2/2]
516			return $1 if /No\.[ 0-9]+ (\S+\....) (?:\d+ bytes )?\[/;
517
518			# try to detect some common forms of filenames
519			return $1 if /([a-z0-9_\-+.]{3,}\.[a-z]{3,4}(?:.\d+))/i;
520
521			# otherwise just pass what we have
522			()
523			};
524
525			# now read all files in the directory uusrc/*
526	root	1.47	for (<uusrc/*>) {
527	root	1.32	my ($retval, $count) = LoadFile ($_, $_, 1);
528			print "file($_), status(", strerror $retval, ") parts($count)\n";
529			}
530	root	1.11
531	root	1.32	SetOption OPT_SAVEPATH, "uudst/";
532	root	1.11
533	root	1.32	# now wade through all files and their source parts
534	root	1.47	for my $uu (GetFileList) {
535			print "file ", $uu->filename, "\n";
536			print " state ", $uu->state, "\n";
537			print " mode ", $uu->mode, "\n";
538			print " uudet ", strencoding $uu->uudet, "\n";
539			print " size ", $uu->size, "\n";
540			print " subfname ", $uu->subfname, "\n";
541			print " mimeid ", $uu->mimeid, "\n";
542			print " mimetype ", $uu->mimetype, "\n";
543	root	1.32
544			# print additional info about all parts
545	root	1.47	print " parts";
546	root	1.32	for ($uu->parts) {
547	root	1.47	for my $k (sort keys %$_) {
548			print " $k=$_->{$k}";
549	root	1.32	}
550			print "\n";
551			}
552
553			$uu->remove_temp;
554
555	root	1.47	if (my $err = $uu->decode) {
556			print " ERROR ", strerror $err, "\n";
557	root	1.32	} else {
558	root	1.47	print " successfully saved as uudst/", $uu->filename, "\n";
559	root	1.32	}
560			}
561	root	1.11
562	root	1.32	print "cleanup...\n";
563	root	1.11
564	root	1.32	CleanUp;
565	root	1.11
566	root	1.46	=head1 PERLMULTICORE SUPPORT
567
568			This module supports the perlmulticore standard (see
569			L<http://perlmulticore.schmorp.de/> for more info) for the following
570			functions - generally these are functions accessing the disk and/or using
571			considerable CPU time:
572
573			LoadFile
574			$item->decode
575			$item->decode_temp
576			$item->remove_temp
577			$item->info
578
579			The perl interpreter will be reacquired/released on every callback
580			invocation, so for performance reasons, callbacks should be avoided if
581			that is costly.
582
583			Future versions might enable multicore support for more functions.
584
585	root	1.45	=head1 BUGS AND LIMITATIONS
586
587			The original uulib library this module uses was written at a time where
588			main memory of measured in megabytes and buffer overflows as a security
589			thign didn't exist. While a lot of security fixes have been applied over
590			the years (includign some defense in depth mechanism that can shield
591			against a lot of as-of-yet undetected bugs), using this library for
592			security purposes requires care.
593
594			Likewise, file sizes when the uulib library was written were tiny compared
595			to today, so do not expect this library to handle files larger than 2GB.
596
597	root	1.1	=head1 AUTHOR
598
599	root	1.23	Marc Lehmann <schmorp@schmorp.de>, the original uulib library was written
600	root	1.11	by Frank Pilhofer <fp@informatik.uni-frankfurt.de>, and later heavily
601			bugfixed by Marc Lehmann.
602	root	1.1
603			=head1 SEE ALSO
604
605	root	1.45	perl(1), uudeview homepage at L<http://www.fpx.de/fp/Software/UUDeview/>.
606	root	1.1
607			=cut
608	root	1.45