ascii85(n) Text encoding & decoding binary data ascii85(n)______________________________________________________________________________NAMEascii85 - 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
_________________________________________________________________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://source‐
forge.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 Gavilán
base64 1.0 ascii85(n)