xref: /openbmc/openpower-vpd-parser/vpd-manager/include/utility/common_utility.hpp (revision fa5e4d325ef9cea3c841fe89d202c340f92bd8c6)
1 #pragma once
2 
3 #include "constants.hpp"
4 #include "logger.hpp"
5 
6 #include <algorithm>
7 #include <cstdio>
8 #include <cstdlib>
9 #include <vector>
10 
11 /**
12  * @brief Namespace to host common utility methods.
13  *
14  * A method qualifies as a common utility function if,
15  * A)It is being used by the utility namespace at the same level as well as
16  * other files directly.
17  * B) The utility should be a leaf node and should not be dependent on any other
18  * utility.
19  *                  *******************
20  *                  | Commmon Utility | - - - - - - -
21  *                  *******************              |
22  *                          /\                       |
23  *                         /  \                      |
24  *         ****************    ****************      |
25  *         | json utility |    | dbus utility |      |
26  *         ****************    ****************      |
27  *                 \                 /               |
28  *                  \               /                |
29  *               ************************            |
30  *               | Vpd specific Utility | - - - - - - -
31  *               ************************
32  */
33 
34 namespace vpd
35 {
36 
37 namespace commonUtility
38 {
39 /** @brief Return the hex representation of the incoming byte.
40  *
41  * @param [in] i_aByte - The input byte.
42  * @returns Hex representation of the byte as a character.
43  */
toHex(size_t i_aByte)44 constexpr auto toHex(size_t i_aByte)
45 {
46     constexpr auto l_map = "0123456789abcdef";
47     return l_map[i_aByte];
48 }
49 
50 /**
51  * @brief API to return null at the end of variadic template args.
52  *
53  * @return empty string.
54  */
getCommand()55 inline std::string getCommand()
56 {
57     return "";
58 }
59 
60 /**
61  * @brief API to arrange create command.
62  *
63  * @param[in] arguments to create the command
64  * @return Command string
65  */
66 template <typename T, typename... Types>
getCommand(T i_arg1,Types...i_args)67 inline std::string getCommand(T i_arg1, Types... i_args)
68 {
69     std::string l_cmd = " " + i_arg1 + getCommand(i_args...);
70 
71     return l_cmd;
72 }
73 
74 /**
75  * @brief API to create shell command and execute.
76  *
77  * @throw std::runtime_error.
78  *
79  * @param[in] arguments for command
80  * @returns output of that command
81  */
82 template <typename T, typename... Types>
executeCmd(T && i_path,Types...i_args)83 inline std::vector<std::string> executeCmd(T&& i_path, Types... i_args)
84 {
85     std::vector<std::string> l_cmdOutput;
86     std::array<char, constants::CMD_BUFFER_LENGTH> l_buffer;
87 
88     std::string l_cmd = i_path + getCommand(i_args...);
89 
90     std::unique_ptr<FILE, decltype(&pclose)> l_cmdPipe(
91         popen(l_cmd.c_str(), "r"), pclose);
92 
93     if (!l_cmdPipe)
94     {
95         logging::logMessage(
96             "popen failed with error " + std::string(strerror(errno)));
97         throw std::runtime_error("popen failed!");
98     }
99     while (fgets(l_buffer.data(), l_buffer.size(), l_cmdPipe.get()) != nullptr)
100     {
101         l_cmdOutput.emplace_back(l_buffer.data());
102     }
103 
104     return l_cmdOutput;
105 }
106 
107 /** @brief Converts string to lower case.
108  *
109  * @param [in] i_string - Input string.
110  */
toLower(std::string & i_string)111 inline void toLower(std::string& i_string)
112 {
113     std::transform(i_string.begin(), i_string.end(), i_string.begin(),
114                    [](unsigned char l_char) { return std::tolower(l_char); });
115 }
116 } // namespace commonUtility
117 } // namespace vpd
118