Created
December 6, 2011 05:56
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Base64 encode/decode for Codea (Lua)
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-- Lua 5.1+ base64 v3.0 (c) 2009 by Alex Kloss <alexthkloss@web.de> | |
-- licensed under the terms of the LGPL2 | |
-- character table string | |
local b='ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/' | |
-- encoding | |
function enc(data) | |
return ((data:gsub('.', function(x) | |
local r,b='',x:byte() | |
for i=8,1,-1 do r=r..(b%2^i-b%2^(i-1)>0 and '1' or '0') end | |
return r; | |
end)..'0000'):gsub('%d%d%d?%d?%d?%d?', function(x) | |
if (#x < 6) then return '' end | |
local c=0 | |
for i=1,6 do c=c+(x:sub(i,i)=='1' and 2^(6-i) or 0) end | |
return b:sub(c+1,c+1) | |
end)..({ '', '==', '=' })[#data%3+1]) | |
end | |
-- decoding | |
function dec(data) | |
data = string.gsub(data, '[^'..b..'=]', '') | |
return (data:gsub('.', function(x) | |
if (x == '=') then return '' end | |
local r,f='',(b:find(x)-1) | |
for i=6,1,-1 do r=r..(f%2^i-f%2^(i-1)>0 and '1' or '0') end | |
return r; | |
end):gsub('%d%d%d?%d?%d?%d?%d?%d?', function(x) | |
if (#x ~= 8) then return '' end | |
local c=0 | |
for i=1,8 do c=c+(x:sub(i,i)=='1' and 2^(7-i) or 0) end | |
return string.char(c) | |
end)) |
from quick lookup seems missing end
for dec()
function, also dec()
function works improperly, proper version is here http://lua-users.org/wiki/BaseSixtyFour
looks like you need one more end
line 35
in line 32 it mast be "for i=1,8 do c=c+(x:sub(i,i)=='1' and 2^(8-i) or 0) end" ?
Hey. how to add support for another language?
in line 32 it mast be "for i=1,8 do c=c+(x:sub(i,i)=='1' and 2^(8-i) or 0) end" ?
Yes it's 8. He didn't correct it yet
"yet"? It's a decade old and not my code - I just copied/pasted it here for a project long ago. 7 years ago rafis posted a link to a proper version. Go use that. FWIW - It worked when I used it way back when. YMMV.
Giỏi.yith"÷%(×'
Higiy
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Thanks bro, good code!