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



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NAME
       ascii85 - ascii85-encode/decode binary data

SYNOPSIS
       package require Tcl  8.4

       package require ascii85  ?1.0?

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

       ::ascii85::decode string

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DESCRIPTION
       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.

EXAMPLES
              % 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]]


REFERENCES
       [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

BUGS, IDEAS, FEEDBACK
       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.

KEYWORDS
       ascii85, encoding

CATEGORY
       Text processing

COPYRIGHT
       Copyright (c) 2010, Emiliano Gavilan




base64                                1.0                           ascii85(n)
