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


NAME

yencode - Y-encode/decode binary data

SYNOPSIS

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)

 




 


DESCRIPTION

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.




OPTIONS



  
-filename name

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





  
-name string

  
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".





  
-line integer

  
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.





  
-crc32 boolean

  
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







REFERENCES



  
[1]

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




BUGS, IDEAS, FEEDBACK

This document, and the package it describes, will undoubtedly contain bugs and
  other problems. Please report such in the category base64 of the
  Tcllib SF Trackers [http://sourceforge.net/tracker/?group_id=12883].
  Please also report any ideas for enhancements you may have for either package
  and/or documentation.

KEYWORDS

encoding, yEnc, ydecode, yencode

CATEGORY

Text processing

COPYRIGHT


Copyright (c) 2002, Pat Thoyts








  

    1.1.2
    base64