1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
|
%% Feel free to use, reuse and abuse the code in this file.
%% @doc Pastebin handler.
-module(toppage_handler).
%% REST Callbacks
-export([init/3]).
-export([allowed_methods/2]).
-export([content_types_provided/2]).
-export([content_types_accepted/2]).
-export([resource_exists/2]).
%% Callback Callbacks
-export([create_paste/2]).
-export([paste_html/2]).
-export([paste_text/2]).
init(_Transport, _Req, []) ->
% For the random number generator:
{X, Y, Z} = now(),
random:seed(X, Y, Z),
{upgrade, protocol, cowboy_rest}.
allowed_methods(Req, State) ->
{[<<"GET">>, <<"POST">>], Req, State}.
content_types_provided(Req, State) ->
{[
{{<<"text">>, <<"plain">>, []}, paste_text},
{{<<"text">>, <<"html">>, []}, paste_html}
], Req, State}.
content_types_accepted(Req, State) ->
{[{{<<"application">>, <<"x-www-form-urlencoded">>, []}, create_paste}],
Req, State}.
resource_exists(Req, _State) ->
case cowboy_req:binding(paste_id, Req) of
{undefined, Req2} ->
{true, Req2, index};
{PasteID, Req2} ->
case valid_path(PasteID) and file_exists(PasteID) of
true -> {true, Req2, PasteID};
false -> {false, Req2, PasteID}
end
end.
create_paste(Req, State) ->
PasteID = new_paste_id(),
{ok, [{<<"paste">>, Paste}], Req3} = cowboy_req:body_qs(Req),
ok = file:write_file(full_path(PasteID), Paste),
case cowboy_req:method(Req3) of
{<<"POST">>, Req4} ->
{<<$/, PasteID/binary>>, Req4, State};
{_, Req4} ->
{true, Req4, State}
end.
paste_html(Req, index) ->
{read_file("index.html"), Req, index};
paste_html(Req, Paste) ->
{Style, Req2} = cowboy_req:qs_val(<<"lang">>, Req, plain),
{format_html(Paste, Style), Req2, Paste}.
paste_text(Req, index) ->
{read_file("index.txt"), Req, index};
paste_text(Req, Paste) ->
{Style, Req2} = cowboy_req:qs_val(<<"lang">>, Req, plain),
{format_text(Paste, Style), Req2, Paste}.
% Private
read_file(Name) ->
{ok, Binary} = file:read_file(full_path(Name)),
Binary.
full_path(Name) ->
{ok, Cwd} = file:get_cwd(),
filename:join([Cwd, "priv", Name]).
file_exists(Name) ->
case file:read_file_info(full_path(Name)) of
{ok, _Info} -> true;
{error, _Reason} -> false
end.
valid_path(<<>>) -> true;
valid_path(<<$., _T/binary>>) -> false;
valid_path(<<$/, _T/binary>>) -> false;
valid_path(<<_Char, T/binary>>) -> valid_path(T).
new_paste_id() ->
Initial = random:uniform(62) - 1,
new_paste_id(<<Initial>>, 7).
new_paste_id(Bin, 0) ->
Chars = <<"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890">>,
<< <<(binary_part(Chars, B, 1))/binary>> || <<B>> <= Bin >>;
new_paste_id(Bin, Rem) ->
Next = random:uniform(62) - 1,
new_paste_id(<<Bin/binary, Next>>, Rem - 1).
format_html(Paste, plain) ->
Text = escape_html_chars(read_file(Paste)),
<<"<!DOCTYPE html><html>",
"<head><title>paste</title></head>",
"<body><pre><code>", Text/binary, "</code></pre></body></html>\n">>;
format_html(Paste, Lang) ->
highlight(full_path(Paste), Lang, "html").
format_text(Paste, plain) ->
read_file(Paste);
format_text(Paste, Lang) ->
highlight(full_path(Paste), Lang, "ansi").
highlight(Path, Lang, Type) ->
Path1 = binary_to_list(Path),
Lang1 = binary_to_list(Lang),
os:cmd(["highlight --syntax=", Lang1,
" --doc-title=paste ",
" --out-format=", Type,
" --include-style ", Path1]).
% Escape some HTML characters that might make a fuss
escape_html_chars(Bin) ->
<< <<(escape_html_char(B))/binary>> || <<B>> <= Bin >>.
escape_html_char($<) -> <<"<">>;
escape_html_char($>) -> <<">">>;
escape_html_char($&) -> <<"&">>;
escape_html_char(C) -> <<C>>.
|
