[//000000001]: # (tcl::transform::rot \- Reflected/virtual channel support)
[//000000002]: # (Generated from file 'rot\.man' by tcllib/doctools with format 'markdown')
[//000000003]: # (Copyright &copy; 2009 Andreas Kupries <andreas\_kupries@users\.sourceforge\.net>)
[//000000004]: # (tcl::transform::rot\(n\) 1 tcllib "Reflected/virtual channel support")

<hr> [ <a href="../../../../toc.md">Main Table Of Contents</a> &#124; <a
href="../../../toc.md">Table Of Contents</a> &#124; <a
href="../../../../index.md">Keyword Index</a> &#124; <a
href="../../../../toc0.md">Categories</a> &#124; <a
href="../../../../toc1.md">Modules</a> &#124; <a
href="../../../../toc2.md">Applications</a> ] <hr>

# NAME

tcl::transform::rot \- rot\-encryption

# <a name='toc'></a>Table Of Contents

  - [Table Of Contents](#toc)

  - [Synopsis](#synopsis)

  - [Description](#section1)

  - [API](#section2)

  - [Bugs, Ideas, Feedback](#section3)

  - [Keywords](#keywords)

  - [Category](#category)

  - [Copyright](#copyright)

# <a name='synopsis'></a>SYNOPSIS

package require Tcl 8\.6  
package require tcl::transform::core ?1?  
package require tcl::transform::rot ?1?  

[__::tcl::transform::rot__ *chan* *key*](#1)  

# <a name='description'></a>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](vt\_otp\.md)__\.

The internal __[TclOO](\.\./\.\./\.\./\.\./index\.md\#tcloo)__ class implementing
the transform handler is a sub\-class of the
__[tcl::transform::core](\.\./virtchannel\_core/transformcore\.md)__
framework\.

# <a name='section2'></a>API

  - <a name='1'></a>__::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\.

# <a name='section3'></a>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\.

# <a name='keywords'></a>KEYWORDS

[caesar cipher](\.\./\.\./\.\./\.\./index\.md\#caesar\_cipher), [channel
transformation](\.\./\.\./\.\./\.\./index\.md\#channel\_transformation),
[cipher](\.\./\.\./\.\./\.\./index\.md\#cipher),
[decryption](\.\./\.\./\.\./\.\./index\.md\#decryption),
[encryption](\.\./\.\./\.\./\.\./index\.md\#encryption), [reflected
channel](\.\./\.\./\.\./\.\./index\.md\#reflected\_channel),
[rot](\.\./\.\./\.\./\.\./index\.md\#rot), [rot13](\.\./\.\./\.\./\.\./index\.md\#rot13),
[tip 230](\.\./\.\./\.\./\.\./index\.md\#tip\_230),
[transformation](\.\./\.\./\.\./\.\./index\.md\#transformation), [virtual
channel](\.\./\.\./\.\./\.\./index\.md\#virtual\_channel)

# <a name='category'></a>CATEGORY

Channels

# <a name='copyright'></a>COPYRIGHT

Copyright &copy; 2009 Andreas Kupries <andreas\_kupries@users\.sourceforge\.net>