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
|
% Licensed under the Apache License, Version 2.0 (the "License"); you may not
% use this file except in compliance with the License. You may obtain a copy of
% the License at
%
% http://www.apache.org/licenses/LICENSE-2.0
%
% Unless required by applicable law or agreed to in writing, software
% distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
% WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
% License for the specific language governing permissions and limitations under
% the License.
%% @doc Saves a Key/Value pair to a ini file. The Key consists of a Section
%% and Option combination. If that combination is found in the ini file
%% the new value replaces the old value. If only the Section is found the
%% Option and value combination is appended to the Section. If the Section
%% does not yet exist in the ini file, it is added and the Option/Value
%% pair is appended.
%% @see couch_config
-module(couch_config_writer).
-export([save_to_file/2]).
%% @spec save_to_file(
%% Config::{{Section::string(), Option::string()}, Value::string()},
%% File::filename()) -> ok
%% @doc Saves a Section/Key/Value triple to the ini file File::filename()
save_to_file({{Section, Key}, Value}, File) ->
{ok, OldFileContents} = file:read_file(File),
Lines = re:split(OldFileContents, "\r\n|\n|\r|\032", [{return, list}]),
SectionLine = "[" ++ Section ++ "]",
{ok, Pattern} = re:compile(["^(", Key, "\\s*=)|\\[[a-zA-Z0-9\_-]*\\]"]),
NewLines = process_file_lines(Lines, [], SectionLine, Pattern, Key, Value),
NewFileContents = reverse_and_add_newline(strip_empty_lines(NewLines), []),
case file:write_file(File, NewFileContents) of
ok ->
ok;
{error, eacces} ->
{file_permission_error, File};
Error ->
Error
end.
process_file_lines([Section|Rest], SeenLines, Section, Pattern, Key, Value) ->
process_section_lines(Rest, [Section|SeenLines], Pattern, Key, Value);
process_file_lines([Line|Rest], SeenLines, Section, Pattern, Key, Value) ->
process_file_lines(Rest, [Line|SeenLines], Section, Pattern, Key, Value);
process_file_lines([], SeenLines, Section, _Pattern, Key, Value) ->
% Section wasn't found. Append it with the option here.
[Key ++ " = " ++ Value, Section, "" | strip_empty_lines(SeenLines)].
process_section_lines([Line|Rest], SeenLines, Pattern, Key, Value) ->
case re:run(Line, Pattern, [{capture, all_but_first}]) of
nomatch -> % Found nothing interesting. Move on.
process_section_lines(Rest, [Line|SeenLines], Pattern, Key, Value);
{match, []} -> % Found another section. Append the option here.
lists:reverse(Rest) ++
[Line, "", Key ++ " = " ++ Value | strip_empty_lines(SeenLines)];
{match, _} -> % Found the option itself. Replace it.
lists:reverse(Rest) ++ [Key ++ " = " ++ Value | SeenLines]
end;
process_section_lines([], SeenLines, _Pattern, Key, Value) ->
% Found end of file within the section. Append the option here.
[Key ++ " = " ++ Value | strip_empty_lines(SeenLines)].
reverse_and_add_newline([Line|Rest], Content) ->
reverse_and_add_newline(Rest, [Line, "\n", Content]);
reverse_and_add_newline([], Content) ->
Content.
strip_empty_lines(["" | Rest]) ->
strip_empty_lines(Rest);
strip_empty_lines(All) ->
All.
|
