NAME

       tcl::transform::rot - rot-encryption

SYNOPSIS

       package require Tcl  8.6

       package require tcl::transform::core  ?1?

       package require tcl::transform::rot  ?1?

       ::tcl::transform::rot chan key

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DESCRIPTION

       The tcl::transform::rot package provides a command creating a channel transformation which
       performs primitive encryption (on writing) and decryption (on reading) on  the  alphabetic
       characters. The algorithm is the Caesar-cipher, a specific variant of which is rot13.

       A related transformations in this module is tcl::transform::otp.

       The  internal  TclOO  class  implementing  the  transform  handler  is  a sub-class of the
       tcl::transform::core framework.

API

       ::tcl::transform::rot chan key
              This command creates a rot encryption transformation on top of the channel chan and
              returns its handle.

              The  "key" specifies how far characters are rotated in the alphabet, and is wrapped
              to the range "0...25".

              Note that this transformation affects only bytes in the ranges ASCII  65...90,  and
              97...122,  i.e.  the  upper- and lower-case alphabetic characters, i.e. "A...Z" and
              "a...z". All other bytes are passed through unchanged.

BUGS, IDEAS, FEEDBACK

       This document, and the package it describes,  will  undoubtedly  contain  bugs  and  other
       problems.   Please  report  such  in  the  category  virtchannel  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.

KEYWORDS

       caesar  cipher, channel transformation, cipher, decryption, encryption, reflected channel,
       rot, rot13, tip 230, transformation, virtual channel

CATEGORY

       Channels

COPYRIGHT

       Copyright (c) 2009 Andreas Kupries <andreas_kupries@users.sourceforge.net>