1 /**
2  * Copyright 2017 Google Inc.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *     http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "util.hpp"
18 
19 #include <filesystem>
20 #include <iostream>
21 #include <string>
22 
23 namespace pid_control
24 {
25 
26 /*
27  * There are two basic paths I want to support:
28  * 1. /sys/class/hwmon/hwmon0/pwm1
29  * 2. /sys/devices/platform/ahb/1e786000.pwm-tacho-controller/hwmon/<asterisk
30  * asterisk>/pwm1
31  *
32  * In this latter case, I want to fill in that gap.  Assuming because it's this
33  * path that it'll only have one directory there.
34  */
35 
36 static constexpr auto platform = "/sys/devices/platform/";
37 namespace fs = std::filesystem;
38 
39 std::string FixupPath(std::string original)
40 {
41     std::string::size_type n, x;
42 
43     /* TODO: Consider the merits of using regex for this. */
44     n = original.find("**");
45     x = original.find(platform);
46 
47     if ((n != std::string::npos) && (x != std::string::npos))
48     {
49         /* This path has some missing pieces and we support it. */
50         std::string base = original.substr(0, n);
51         std::string fldr;
52         std::string f = original.substr(n + 2, original.size() - (n + 2));
53 
54         /* Equivalent to glob and grab 0th entry. */
55         for (const auto& folder : fs::directory_iterator(base))
56         {
57             fldr = folder.path();
58             break;
59         }
60 
61         if (!fldr.length())
62         {
63             return original;
64         }
65 
66         return fldr + f;
67     }
68     else
69     {
70         /* It'll throw an exception when we use it if it's still bad. */
71         return original;
72     }
73 }
74 
75 } // namespace pid_control
76