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yencode(n)                          Text encoding & decoding binary data                          yencode(n)



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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)

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DESCRIPTION
       This  package provides a Tcl-only implementation of the yEnc file encoding. This is a recently intro-duced introduced
       duced 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 spe-cial special
       cial 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 tak-ing taking
              ing 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 charac-ters characters
              ters 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 -o=yend
       =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://source -
       forge.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




base64                                              1.1.2                                         yencode(n)