| 1 |
NAME |
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Convert::UUlib - decode uu/xx/b64/mime/yenc/etc-encoded data from a |
| 3 |
massive number of files |
| 4 |
|
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SYNOPSIS |
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use Convert::UUlib ':all'; |
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|
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# read all the files named on the commandline and decode them |
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# into the CURRENT directory. See below for a longer example. |
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LoadFile $_ for @ARGV; |
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|
| 12 |
for my $uu (GetFileList) { |
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if ($uu->state & FILE_OK) { |
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$uu->decode; |
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print $uu->filename, "\n"; |
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} |
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} |
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|
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DESCRIPTION |
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This module started as an interface to the uulib/uudeview library by |
| 21 |
Frank Pilhofer that can be used to decode all kinds of usenet (and |
| 22 |
other) binary messages. |
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|
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After upstream abondoned the project, th library was continuously |
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bugfixed and improved in this module, with major focuses on security |
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fixes, correctness and speed (that does not mean that this library is |
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considered safe with untrusted data, but it surely is safer than the |
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poriginal uudeview). |
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|
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Read the file doc/library.pdf from the distribution for in-depth |
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information about the C-library used in this interface, and the rest of |
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this document and especially the non-trivial decoder program at the end. |
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|
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EXPORTED CONSTANTS |
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Action code constants |
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ACT_IDLE we don't do anything |
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ACT_SCANNING scanning an input file |
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ACT_DECODING decoding into a temp file |
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ACT_COPYING copying temp to target |
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ACT_ENCODING encoding a file |
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|
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Message severity levels |
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MSG_MESSAGE just a message, nothing important |
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MSG_NOTE something that should be noticed |
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MSG_WARNING important msg, processing continues |
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MSG_ERROR processing has been terminated |
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MSG_FATAL decoder cannot process further requests |
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MSG_PANIC recovery impossible, app must terminate |
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|
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Options |
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OPT_VERSION version number MAJOR.MINORplPATCH (ro) |
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OPT_FAST assumes only one part per file |
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OPT_DUMBNESS switch off the program's intelligence |
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OPT_BRACKPOL give numbers in [] higher precendence |
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OPT_VERBOSE generate informative messages |
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OPT_DESPERATE try to decode incomplete files |
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OPT_IGNREPLY ignore RE:plies (off by default) |
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OPT_OVERWRITE whether it's OK to overwrite ex. files |
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OPT_SAVEPATH prefix to save-files on disk |
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OPT_IGNMODE ignore the original file mode |
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OPT_DEBUG print messages with FILE/LINE info |
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OPT_ERRNO get last error code for RET_IOERR (ro) |
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OPT_PROGRESS retrieve progress information |
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OPT_USETEXT handle text messages |
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OPT_PREAMB handle Mime preambles/epilogues |
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OPT_TINYB64 detect short B64 outside of Mime |
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OPT_ENCEXT extension for single-part encoded files |
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OPT_REMOVE remove input files after decoding (dangerous) |
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OPT_MOREMIME strict MIME adherence |
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OPT_DOTDOT ".."-unescaping has not yet been done on input files |
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OPT_RBUF set default read I/O buffer size in bytes |
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OPT_WBUF set default write I/O buffer size in bytes |
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OPT_AUTOCHECK automatically check file list after every loadfile |
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|
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Result/Error codes |
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RET_OK everything went fine |
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RET_IOERR I/O Error - examine errno |
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RET_NOMEM not enough memory |
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RET_ILLVAL illegal value for operation |
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RET_NODATA decoder didn't find any data |
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RET_NOEND encoded data wasn't ended properly |
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RET_UNSUP unsupported function (encoding) |
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RET_EXISTS file exists (decoding) |
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RET_CONT continue -- special from ScanPart |
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RET_CANCEL operation canceled |
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|
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File States |
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This code is zero, i.e. "false": |
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|
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UUFILE_READ Read in, but not further processed |
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|
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The following state codes are or'ed together: |
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|
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FILE_MISPART Missing Part(s) detected |
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FILE_NOBEGIN No 'begin' found |
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FILE_NOEND No 'end' found |
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FILE_NODATA File does not contain valid uudata |
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FILE_OK All Parts found, ready to decode |
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FILE_ERROR Error while decoding |
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FILE_DECODED Successfully decoded |
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FILE_TMPFILE Temporary decoded file exists |
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|
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Encoding types |
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UU_ENCODED UUencoded data |
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B64_ENCODED Mime-Base64 data |
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XX_ENCODED XXencoded data |
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BH_ENCODED Binhex encoded |
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PT_ENCODED Plain-Text encoded (MIME) |
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QP_ENCODED Quoted-Printable (MIME) |
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YENC_ENCODED yEnc encoded (non-MIME) |
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|
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EXPORTED FUNCTIONS |
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Initializing and cleanup |
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Initialize is automatically called when the module is loaded and |
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allocates quite a small amount of memory for todays machines ;) CleanUp |
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releases that again. |
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|
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On my machine, a fairly complete decode with DBI backend needs about |
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10MB RSS to decode 20000 files. |
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|
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CleanUp |
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Release memory, file items and clean up files. Should be called |
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after a decoidng run, if you want to start a new one. |
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|
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Setting and querying options |
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$option = GetOption OPT_xxx |
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SetOption OPT_xxx, opt-value |
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|
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See the "OPT_xxx" constants above to see which options exist. |
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|
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Setting various callbacks |
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SetMsgCallback [callback-function] |
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SetBusyCallback [callback-function] |
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SetFileCallback [callback-function] |
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SetFNameFilter [callback-function] |
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|
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Call the currently selected FNameFilter |
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$file = FNameFilter $file |
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|
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Loading sourcefiles, optionally fuzzy merge and start decoding |
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($retval, $count) = LoadFile $fname, [$id, [$delflag, [$partno]]] |
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Load the given file and scan it for encoded contents. Optionally tag |
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it with the given id, and if $delflag is true, delete the file after |
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it is no longer necessary. If you are certain of the part number, |
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you can specify it as the last argument. |
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|
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A better (usually faster) way of doing this is using the |
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"SetFNameFilter" functionality. |
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|
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$retval = Smerge $pass |
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If you are desperate, try to call "Smerge" with increasing $pass |
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values, beginning at 0, to try to merge parts that usually would not |
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have been merged. |
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|
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Most probably this will result in garbled files, so never do this by |
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default, except: |
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|
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If the "OPT_AUTOCHECK" option has been disabled (by default it is |
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enabled) to speed up file loading, then you *have* to call "Smerge |
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-1" after loading all files as an additional pre-pass (which is |
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normally done by "LoadFile"). |
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|
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$item = GetFileListItem $item_number |
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Return the $item structure for the $item_number'th found file, or |
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"undef" of no file with that number exists. |
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|
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The first file has number 0, and the series has no holes, so you can |
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iterate over all files by starting with zero and incrementing until |
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you hit "undef". |
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|
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This function has to walk the linear list of fils on each access, so |
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if you want to iterate over all items, it is usually faster to use |
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"GetFileList". |
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|
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@items = GetFileList |
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Similar to "GetFileListItem", but returns all files in one go, which |
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is very much faster for large number of items, and has no drawbacks |
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when used for a small number of items. |
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|
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Decoding files |
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$retval = $item->rename ($newname) |
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Change the ondisk filename where the decoded file will be saved. |
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|
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$retval = $item->decode_temp |
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Decode the file into a temporary location, use "$item->infile" to |
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retrieve the temporary filename. |
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|
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$retval = $item->remove_temp |
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Remove the temporarily decoded file again. |
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|
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$retval = $item->decode ([$target_path]) |
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Decode the file to its destination, or the given target path. |
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|
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$retval = $item->info (callback-function) |
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|
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Querying (and setting) item attributes |
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$state = $item->state |
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$mode = $item->mode ([newmode]) |
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$uudet = $item->uudet |
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$size = $item->size |
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$filename = $item->filename ([newfilename}) |
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$subfname = $item->subfname |
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$mimeid = $item->mimeid |
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$mimetype = $item->mimetype |
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$binfile = $item->binfile |
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|
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Information about source parts |
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$parts = $item->parts |
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Return information about all parts (source files) used to decode the |
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file as a list of hashrefs with the following structure: |
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|
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{ |
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partno => <integer describing the part number, starting with 1>, |
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# the following member sonly exist when they contain useful information |
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sfname => <local pathname of the file where this part is from>, |
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filename => <the ondisk filename of the decoded file>, |
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subfname => <used to cluster postings, possibly the posting filename>, |
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subject => <the subject of the posting/mail>, |
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origin => <the possible source (From) address>, |
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mimetype => <the possible mimetype of the decoded file>, |
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mimeid => <the id part of the Content-Type>, |
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} |
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|
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Usually you are interested mostly the "sfname" and possibly the |
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"partno" and "filename" members. |
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|
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Functions below are not documented and not very well tested - feedback welcome |
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QuickDecode |
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EncodeMulti |
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EncodePartial |
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EncodeToStream |
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EncodeToFile |
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E_PrepSingle |
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E_PrepPartial |
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|
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EXTENSION FUNCTIONS |
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Functions found in this module but not documented in the uulib |
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documentation: |
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|
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$msg = straction ACT_xxx |
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Return a human readable string representing the given action code. |
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|
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$msg = strerror RET_xxx |
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Return a human readable string representing the given error code. |
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|
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$str = strencoding xxx_ENCODED |
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Return the name of the encoding type as a string. |
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|
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$str = strmsglevel MSG_xxx |
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Returns the message level as a string. |
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|
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SetFileNameCallback $cb |
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Sets (or queries) the FileNameCallback, which is called whenever the |
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decoding library can't find a filename and wants to extract a |
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filename from the subject line of a posting. The callback will be |
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called with two arguments, the subject line and the current |
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candidate for the filename. The latter argument can be "undef", |
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which means that no filename could be found (and likely no one |
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exists, so it is safe to also return "undef" in this case). If it |
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doesn't return anything (not even "undef"!), then nothing happens, |
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so this is a no-op callback: |
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|
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sub cb { |
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return (); |
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} |
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|
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If it returns "undef", then this indicates that no filename could be |
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found. In all other cases, the return value is taken to be the |
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filename. |
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|
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This is a slightly more useful callback: |
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|
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sub cb { |
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return unless $_[1]; # skip "Re:"-plies et al. |
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my ($subject, $filename) = @_; |
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# if we find some *.rar, take it |
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return $1 if $subject =~ /(\w+\.rar)/; |
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# otherwise just pass what we have |
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return (); |
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} |
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|
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LARGE EXAMPLE DECODER |
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The general workflow for decoding is like this: |
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|
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1. Configure options with "SetOption" or "SetXXXCallback". |
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2. Load all source files with "LoadFile". |
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3. Optionally "Smerge". |
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4. Iterate over all "GetFileList" items (i.e. result files). |
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5. "CleanUp" to delete files and free items. |
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|
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What follows is the file "example-decoder" from the distribution that |
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illustrates the above worklfow in a non-trivial example. |
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|
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#!/usr/bin/perl |
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|
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# decode all the files in the directory uusrc/ and copy |
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# the resulting files to uudst/ |
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|
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use Convert::UUlib ':all'; |
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|
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sub namefilter { |
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my ($path) = @_; |
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|
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$path=~s/^.*[\/\\]//; |
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|
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$path |
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} |
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|
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sub busycb { |
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my ($action, $curfile, $partno, $numparts, $percent, $fsize) = @_; |
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$_[0]=straction($action); |
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print "busy_callback(", (join ",",@_), ")\n"; |
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0 |
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} |
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|
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SetOption OPT_RBUF, 128*1024; |
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SetOption OPT_WBUF, 1024*1024; |
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SetOption OPT_IGNMODE, 1; |
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SetOption OPT_IGNMODE, 1; |
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SetOption OPT_VERBOSE, 1; |
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SetOption OPT_AUTOCHK, 0; |
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|
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# show the three ways you can set callback functions. I normally |
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# prefer the one with the sub inplace. |
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SetFNameFilter \&namefilter; |
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|
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SetBusyCallback "busycb", 333; |
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|
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SetMsgCallback sub { |
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my ($msg, $level) = @_; |
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print uc strmsglevel $_[1], ": $msg\n"; |
| 332 |
}; |
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|
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# the following non-trivial FileNameCallback takes care |
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# of some subject lines not detected properly by uulib: |
| 336 |
SetFileNameCallback sub { |
| 337 |
return unless $_[1]; # skip "Re:"-plies et al. |
| 338 |
local $_ = $_[0]; |
| 339 |
|
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# the following rules are rather effective on some newsgroups, |
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# like alt.binaries.games.anime, where non-mime, uuencoded data |
| 342 |
# is very common |
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|
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# if we find some *.rar, take it as the filename |
| 345 |
return $1 if /(\S{3,}\.(?:[rstuvwxyz]\d\d|rar))\s/i; |
| 346 |
|
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# one common subject format |
| 348 |
return $1 if /- "(.{2,}?\..+?)" (?:yenc )?\(\d+\/\d+\)/i; |
| 349 |
|
| 350 |
# - filename.par (04/55) |
| 351 |
return $1 if /- "?(\S{3,}\.\S+?)"? (?:yenc )?\(\d+\/\d+\)/i; |
| 352 |
|
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# - (xxx) No. 1 sayuri81.jpg 756565 bytes |
| 354 |
# - (20 files) No.17 Roseanne.jpg [2/2] |
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return $1 if /No\.[ 0-9]+ (\S+\....) (?:\d+ bytes )?\[/; |
| 356 |
|
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# try to detect some common forms of filenames |
| 358 |
return $1 if /([a-z0-9_\-+.]{3,}\.[a-z]{3,4}(?:.\d+))/i; |
| 359 |
|
| 360 |
# otherwise just pass what we have |
| 361 |
() |
| 362 |
}; |
| 363 |
|
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# now read all files in the directory uusrc/* |
| 365 |
for (<uusrc/*>) { |
| 366 |
my ($retval, $count) = LoadFile ($_, $_, 1); |
| 367 |
print "file($_), status(", strerror $retval, ") parts($count)\n"; |
| 368 |
} |
| 369 |
|
| 370 |
Smerge -1; |
| 371 |
|
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SetOption OPT_SAVEPATH, "uudst/"; |
| 373 |
|
| 374 |
# now wade through all files and their source parts |
| 375 |
for my $uu (GetFileList) { |
| 376 |
print "file ", $uu->filename, "\n"; |
| 377 |
print " state ", $uu->state, "\n"; |
| 378 |
print " mode ", $uu->mode, "\n"; |
| 379 |
print " uudet ", strencoding $uu->uudet, "\n"; |
| 380 |
print " size ", $uu->size, "\n"; |
| 381 |
print " subfname ", $uu->subfname, "\n"; |
| 382 |
print " mimeid ", $uu->mimeid, "\n"; |
| 383 |
print " mimetype ", $uu->mimetype, "\n"; |
| 384 |
|
| 385 |
# print additional info about all parts |
| 386 |
print " parts"; |
| 387 |
for ($uu->parts) { |
| 388 |
for my $k (sort keys %$_) { |
| 389 |
print " $k=$_->{$k}"; |
| 390 |
} |
| 391 |
print "\n"; |
| 392 |
} |
| 393 |
|
| 394 |
$uu->remove_temp; |
| 395 |
|
| 396 |
if (my $err = $uu->decode) { |
| 397 |
print " ERROR ", strerror $err, "\n"; |
| 398 |
} else { |
| 399 |
print " successfully saved as uudst/", $uu->filename, "\n"; |
| 400 |
} |
| 401 |
} |
| 402 |
|
| 403 |
print "cleanup...\n"; |
| 404 |
|
| 405 |
CleanUp; |
| 406 |
|
| 407 |
PERLMULTICORE SUPPORT |
| 408 |
This module supports the perlmulticore standard (see |
| 409 |
<http://perlmulticore.schmorp.de/> for more info) for the following |
| 410 |
functions - generally these are functions accessing the disk and/or |
| 411 |
using considerable CPU time: |
| 412 |
|
| 413 |
LoadFile |
| 414 |
$item->decode |
| 415 |
$item->decode_temp |
| 416 |
$item->remove_temp |
| 417 |
$item->info |
| 418 |
|
| 419 |
The perl interpreter will be reacquired/released on every callback |
| 420 |
invocation, so for performance reasons, callbacks should be avoided if |
| 421 |
that is costly. |
| 422 |
|
| 423 |
Future versions might enable multicore support for more functions. |
| 424 |
|
| 425 |
BUGS AND LIMITATIONS |
| 426 |
The original uulib library this module uses was written at a time where |
| 427 |
main memory of measured in megabytes and buffer overflows as a security |
| 428 |
thign didn't exist. While a lot of security fixes have been applied over |
| 429 |
the years (includign some defense in depth mechanism that can shield |
| 430 |
against a lot of as-of-yet undetected bugs), using this library for |
| 431 |
security purposes requires care. |
| 432 |
|
| 433 |
Likewise, file sizes when the uulib library was written were tiny |
| 434 |
compared to today, so do not expect this library to handle files larger |
| 435 |
than 2GB. |
| 436 |
|
| 437 |
Lastly, this module uses a very "C-like" interface, which means it |
| 438 |
doesn't protect you from invalid points as you might expect from "more |
| 439 |
perlish" modules - for example, accessing a file item object after |
| 440 |
callinbg "CleanUp" will likely result in crashes, memory corruption, or |
| 441 |
worse. |
| 442 |
|
| 443 |
AUTHOR |
| 444 |
Marc Lehmann <schmorp@schmorp.de>, the original uulib library was |
| 445 |
written by Frank Pilhofer <fp@informatik.uni-frankfurt.de>, and later |
| 446 |
heavily bugfixed by Marc Lehmann. |
| 447 |
|
| 448 |
SEE ALSO |
| 449 |
perl(1), uudeview homepage at <http://www.fpx.de/fp/Software/UUDeview/>. |
| 450 |
|
