webmcp
view framework/env/encode/mime/base64.lua @ 3:795b764629ca
Version 1.0.3
Important bugfix related to internal forwards (Bug was introduced by the restriction of views with underscore prefix in Version 1.0.2)
Important bugfix related to internal forwards (Bug was introduced by the restriction of views with underscore prefix in Version 1.0.2)
| author | jbe |
|---|---|
| date | Thu Dec 10 12:00:00 2009 +0100 (2009-12-10) |
| parents | 9fdfb27f8e67 |
| children |
line source
1 local alphabet = {
2 "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M",
3 "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z",
4 "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m",
5 "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z",
6 "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "+", "/"
7 }
9 function encode.mime.base64(str)
10 local parts = {}
11 local pos = 1
12 local block_count = 0
13 while pos <= #str do
14 local s = string.sub(str, pos, pos + 2)
15 local n = 0
16 for i = 1, 3 do
17 n = n * 256
18 if i <= #s then
19 n = n + string.byte(string.sub(s, i, i))
20 end
21 end
22 parts[#parts+1] = alphabet[math.floor(n / 262144) + 1]
23 parts[#parts+1] = alphabet[math.floor(n / 4096) % 64 + 1]
24 if #s > 1 then
25 parts[#parts+1] = alphabet[math.floor(n / 64) % 64 + 1]
26 else
27 parts[#parts+1] = "="
28 end
29 if #s > 2 then
30 parts[#parts+1] = alphabet[n % 64 + 1]
31 else
32 parts[#parts+1] = "="
33 end
34 block_count = block_count + 1
35 if block_count == 19 then
36 parts[#parts+1] = "\r\n"
37 block_count = 0
38 end
39 pos = pos + #s
40 end
41 if block_count > 0 then
42 parts[#parts+1] = "\r\n"
43 end
44 return table.concat(parts)
45 end