webmcp
view framework/env/encode/mime/unstructured_header_line.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 function encode.mime.unstructured_header_line(key, value)
2 if not value then
3 return ""
4 end
5 local charset = "UTF-8" -- TODO: support other charsets
6 local key_length = #key + #(": ")
7 if string.find(value, "^[\t -~]*$") then
8 local need_encoding = false
9 local parts = { key, ": " }
10 local line_length = key_length
11 local first_line = true
12 for spaced_word in string.gmatch(value, "[\t ]*[^\t ]*") do
13 if #spaced_word + line_length > 76 then
14 if first_line or #spaced_word > 76 then
15 need_encoding = true
16 break
17 end
18 parts[#parts+1] = "\r\n"
19 line_length = 0
20 end
21 parts[#parts+1] = spaced_word
22 line_length = line_length + #spaced_word
23 first_line = false
24 end
25 if not need_encoding then
26 parts[#parts+1] = "\r\n"
27 return table.concat(parts)
28 end
29 charset = "US-ASCII"
30 end
31 local parts = { key, ": " }
32 local line_length
33 local opening = "=?" .. charset .. "?Q?"
34 local closing = "?="
35 local indentation = ""
36 for i = 1, key_length do
37 indentation = indentation .. " "
38 end
39 local open = false
40 for char in string.gmatch(value, ".") do
41 local encoded_char
42 if string.find(char, "^[0-9A-Za-z%.%-]$") then
43 encoded_char = char
44 else
45 local byte = string.byte(char)
46 if byte == 32 then
47 encoded_char = "_"
48 else
49 encoded_char = string.format("=%02X", byte)
50 end
51 end
52 if open and line_length + #encoded_char > 76 then
53 parts[#parts+1] = closing
54 parts[#parts+1] = "\r\n"
55 parts[#parts+1] = indentation
56 open = false
57 end
58 if not open then
59 parts[#parts+1] = opening
60 line_length = key_length + #opening + #closing
61 open = true
62 end
63 parts[#parts+1] = encoded_char
64 line_length = line_length + #encoded_char
65 end
66 if open then
67 parts[#parts+1] = "?="
68 end
69 parts[#parts+1] = "\r\n"
70 return table.concat(parts)
71 end