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

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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 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

base64								       1.1.2							     yencode(3tcl)