UUlib

NAME

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

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 $i = 0; my $uu = GetFileListItem $i; $i++) {
if ($uu−>state & FILE_OK) {
$uu−>decode;
print $uu−>filename, "\n";
}
}

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.

EXPORTED CONSTANTS

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

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

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

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

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

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)

EXPORTED FUNCTIONS

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.
Initialize

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

CleanUp

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

Setting and querying options
$option = GetOption OPT_xxx
SetOption OPT_xxx, opt-value

See the "OPT_xxx" constants above to see which options exist.

Setting various callbacks
SetMsgCallback [callback−function]
SetBusyCallback [callback−function]
SetFileCallback [callback−function]
SetFNameFilter [callback−function]

Call the currently selected FNameFilter
$file = FNameFilter $file

Loading sourcefiles, optionally fuzzy merge and start decoding
($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 $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 "SetFNameFilter" functionality.

$retval = Smerge $pass

If you are desperate, try to call "Smerge" with increasing $pass values, beginning at 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 "OPT_AUTOCHECK" option has been disabled (by default it is enabled) to speed up file loading, then you have to call "Smerge −1" after loading all files as an additional pre-pass (which is normally done by "LoadFile").

$item = GetFileListItem $item_number

Return the $item structure for the $item_number’th found file, or "undef" of no file with that number exists.

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

Decoding files
$retval = $item−>rename($newname)

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

$retval = $item−>decode_temp

Decode the file into a temporary location, use "$item−>infile" to retrieve the temporary filename.

$retval = $item−>remove_temp

Remove the temporarily decoded file again.

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

Decode the file to it’s destination, or the given target path.

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

Querying (and setting) item attributes
$state = $item−>state
$mode = $item−>mode([newmode])
$uudet = $item−>uudet
$size = $item−>size
$filename = $item−>filename([newfilename})
$subfname = $item−>subfname
$mimeid = $item−>mimeid
$mimetype = $item−>mimetype
$binfile = $item−>binfile

Information about source parts
$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 "sfname" and possibly the "partno" and "filename" members.

Functions below not documented and not very well tested
QuickDecode
EncodeMulti
EncodePartial
EncodeToStream
EncodeToFile
E_PrepSingle
E_PrepPartial

EXTENSION FUNCTIONS
Functions found in this module but not documented in the uulib documentation:
$msg = straction ACT_xxx

Return a human readable string representing the given action code.

$msg = strerror RET_xxx

Return a human readable string representing the given error code.

$str = strencoding xxx_ENCODED

Return the name of the encoding type as a string.

$str = strmsglevel MSG_xxx

Returns the message level as a string.

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 "undef", which means that no filename could be found (and likely no one exists, so it is safe to also return "undef" in this case). If it doesn’t return anything (not even "undef"!), then nothing happens, so this is a no-op callback:

sub cb {
return ();
}

If it returns "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 ();
}

LARGE EXAMPLE DECODER

This is the file "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
$i = 0;
while ($uu = GetFileListItem $i) {
$i++;
print "file nr. $i";
print " state ", $uu−>state;
print " mode ", $uu−>mode;
print " uudet ", strencoding $uu−>uudet;
print " size ", $uu−>size;
print " filename ", $uu−>filename;
print " subfname ", $uu−>subfname;
print " mimeid ", $uu−>mimeid;
print " mimetype ", $uu−>mimetype;
print "\n";
# print additional info about all parts
for ($uu−>parts) {
while (my ($k, $v) = each %$_) {
print "$k > $v, ";
}
print "\n";
}
print $uu−>filename;
$uu−>remove_temp;
if (my $err = $uu−>decode ()) {
print ", ", strerror $err, "\n";
} else {
print ", saved as uudst/", $uu−>filename, "\n";
}
}
print "cleanup...\n";
CleanUp;

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.

SEE ALSO

perl(1), uudeview homepage at http://www.uni−frankfurt.de/~fp/uudeview/.