base32::core(n) Base32 encoding base32::core(n) 







base32::core - Expanding basic base32 maps








package require Tcl 8.4


package require base32::core ?0.1?


::base32::core::define map forwvar
    backwvar ivar


::base32::core::valid string pattern
    mvar












This package provides generic commands for the construction of
    full base32 mappings from a basic mapping listing just the codes and
    associated characters. The full mappings, regular and inverse, created here
    map to and from bit sequences, and also handle the partial mappings at the
    end of a string.


This is in essence an internal package to be used by implementors
    of a base32 en- and decoder. A regular user has no need of this package at
    all.









  
::base32::core::define map forwvar backwvar
    ivar

  
This command computes full forward and backward (inverse) mappings from
      the basic map and stores them in the variables named by
      forwvar and backwvar resp. It also constructs a regexp
      pattern for the detection of invalid characters in supposedly base32
      encoded input and stores it in the variable named by ivar.

  
::base32::core::valid string pattern mvar

  
This command checks if the input string is a valid base32 encoded
      string, based on the pattern of invalid characters as generated by
      ::base32::core::define, and some other general rules.
    
The result of the command is a boolean flag. Its value is
        True for a valid string, and False otherwise. In
        the latter case an error message describing the problem with the input
        is stored into the variable named by mvar. The variable is not
        touched if the input was found to be valid.

    
The rules checked by the command, beyond rejection of bad
        characters, are:

  







  
[1]

  
The length of the input is not a multiple of eight,

  
[2]

  
The padding appears not at the end of input, but in the middle,

  
[3]

  
The padding has not of length six, four, three, or one characters,












This document, and the package it describes, will undoubtedly
    contain bugs and other problems. Please report such in the category
    base32 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.








base32








Text processing








Copyright (c) Public domain








  

    0.1
    base32