yencode(3tcl) Text encoding & decoding binary data yencode(3tcl) 







yencode - Y-encode/decode binary data








package require Tcl 8.2


package require yencode ?1.1.2?


::yencode::encode string


::yencode::decode string


::yencode::yencode ?-name string?
    ?-line integer? ?-crc32 boolean? (-file
    filename | ?--? string)


::yencode::ydecode (-file filename |
    ?--? string)












This package provides a Tcl-only implementation of the yEnc file
    encoding. This is a recently introduced method of encoding binary files for
    transmission through Usenet. This encoding packs binary data into a format
    that requires an 8-bit clean transmission layer but that escapes characters
    special to the NNTP posting protocols. See
    http://www.yenc.org/ for details concerning the algorithm.



  
::yencode::encode string

  
returns the yEnc encoded data.

  
::yencode::decode string

  
Decodes the given yEnc encoded data.

  
::yencode::yencode ?-name string? ?-line
    integer? ?-crc32 boolean? (-file filename
    | ?--? string)

  
Encode a file or block of data.

  
::yencode::ydecode (-file filename | ?--?
    string)

  
Decode a file or block of data. A file may contain more than one embedded
      file so the result is a list where each element is a three element list of
      filename, file size and data.











  

  
Cause the yencode or ydecode commands to read their data from the named
      file rather that taking a string parameter.

  

  
The encoded data header line contains the suggested file name to be used
      when unpacking the data. Use this option to change this from the default
      of "data.dat".

  

  
The yencoded data header line contains records the line length used during
      the encoding. Use this option to select a line length other that the
      default of 128. Note that NNTP imposes a 1000 character line length limit
      and some gateways may have trouble with more than 255 characters per
    line.

  

  
The yEnc specification recommends the inclusion of a cyclic redundancy
      check value in the footer. Use this option to change the default from
      true to false.








% set d [yencode::yencode -file testfile.txt]
=ybegin line=128 size=584 name=testfile.txt
 -o- data not shown -o-
=yend size=584 crc32=ded29f4f












  
[1]

  
http://www.yenc.org/yenc-draft.1.3.txt










This document, and the package it describes, will undoubtedly
    contain bugs and other problems. Please report such in the category
    base64 of the Tcllib Trackers
    [http://core.tcl.tk/tcllib/reportlist]. Please also report any ideas for
    enhancements you may have for either package and/or documentation.


When proposing code changes, please provide unified diffs,
    i.e the output of diff -u.


Note further that attachments are strongly preferred over
    inlined patches. Attachments can be made by going to the Edit form of
    the ticket immediately after its creation, and then using the left-most
    button in the secondary navigation bar.








encoding, yEnc, ydecode, yencode








Text processing








Copyright (c) 2002, Pat Thoyts








  

    1.1.2
    tcllib