ascii85(n) Text encoding & decoding binary data ascii85(n) 







ascii85 - ascii85-encode/decode binary data








package require Tcl 8.4


package require ascii85 ?1.0?


::ascii85::encode ?-maxlen maxlen?
    ?-wrapchar wrapchar? string


::ascii85::decode string












This package provides procedures to encode binary data into
    ascii85 and back.



  
::ascii85::encode ?-maxlen maxlen? ?-wrapchar
    wrapchar? string

  
Ascii85 encodes the given binary string and returns the encoded
      result. Inserts the character wrapchar every maxlen
      characters of output. wrapchar defaults to newline. maxlen
      defaults to 76.
    
Note well: If your string is not simple ascii you
        should fix the string encoding before doing ascii85 encoding. See the
        examples.

    
The command will throw an error for negative values of
        maxlen, or if maxlen is not an integer number.

  

  
::ascii85::decode string

  
Ascii85 decodes the given string and returns the binary data. The
      decoder ignores whitespace in the string, as well as tabs and
    newlines.










% ascii85::encode "Hello, world"
87cURD_*#TDfTZ)



% ascii85::encode [string repeat xyz 24]
G^4U[H$X^\H?a^]G^4U[H$X^\H?a^]G^4U[H$X^\H?a^]G^4U[H$X^\H?a^]G^4U[H$X^\H?a^]G
^4U[H$X^\H?a^]
% ascii85::encode -wrapchar "" [string repeat xyz 24]
G^4U[H$X^\H?a^]G^4U[H$X^\H?a^]G^4U[H$X^\H?a^]G^4U[H$X^\H?a^]G^4U[H$X^\H?a^]G^4U[H$X^\H?a^]



# NOTE: ascii85 encodes BINARY strings.
% set chemical [encoding convertto utf-8 "C\u2088H\u2081\u2080N\u2084O\u2082"]
% set encoded [ascii85::encode $chemical]
6fN]R8E,5Pidu\UiduhZidua
% set caffeine [encoding convertfrom utf-8 [ascii85::decode $encoded]]










  
[1]

  
http://en.wikipedia.org/wiki/Ascii85

  
[2]

  
Postscript Language Reference Manual, 3rd Edition, page 131.
      http://www.adobe.com/devnet/postscript/pdfs/PLRM.pdf










This document, and the package it describes, will undoubtedly
    contain bugs and other problems. Please report such in the category
    base64 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.








ascii85, encoding








Text processing








Copyright (c) 2010, Emiliano Gavilán








  

    1.0
    base64