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[comment {-*- tcl -*- doctools manpage}]
[manpage_begin tcl::transform::rot n 1]
[copyright {2009 Andreas Kupries <andreas_kupries@users.sourceforge.net>}]
[moddesc {Reflected/virtual channel support}]
[category Channels]
[titledesc {rot-encryption}]
[require Tcl 8.6]
[require tcl::transform::core [opt 1]]
[require tcl::transform::rot [opt 1]]
[description]
[para]
The [package 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.
[para] A related transformations in this module is
[package tcl::transform::otp].
[para] The internal [package TclOO] class implementing the transform
handler is a sub-class of the [package tcl::transform::core]
framework.
[section API]
[list_begin definitions]
[call [cmd ::tcl::transform::rot] [arg chan] [arg key]]
This command creates a rot encryption transformation on top of the
channel [arg chan] and returns its handle.
[para] The "[arg key]" specifies how far characters are rotated in the
alphabet, and is wrapped to the range "0...25".
[para] 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.
[list_end]
[section {BUGS, IDEAS, FEEDBACK}]
This document, and the package it describes, will undoubtedly contain
bugs and other problems.
Please report such in the category [emph virtchannel] of the
[uri {http://sourceforge.net/tracker/?group_id=12883} {Tcllib SF Trackers}].
Please also report any ideas for enhancements you may have for either
package and/or documentation.
[keywords rot encryption decryption rot13 transformation {channel transformation}]
[keywords {caesar cipher} cipher {virtual channel} {reflected channel} {tip 230}]
[manpage_end]
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