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 Trackers [
http://core.tcl.tk/tcllib/reportlist]. 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