ncsi: Add code to accept command line arguments

Accepts command line arguments for interface index,
ncsi channel,package etc.

Change-Id: Ib2b049a2fb017593a0a4329b26bbd64c65c8b580
Signed-off-by: Ratan Gupta <ratagupt@in.ibm.com>
diff --git a/argument.hpp b/argument.hpp
new file mode 100644
index 0000000..51438b4
--- /dev/null
+++ b/argument.hpp
@@ -0,0 +1,68 @@
+#pragma once
+
+#include <getopt.h>
+#include <map>
+#include <string>
+
+namespace phosphor
+{
+namespace network
+{
+namespace ncsi
+{
+/** @brief Class - Encapsulates parsing command line options and
+ *                 populating arguments
+ */
+class ArgumentParser
+{
+    public:
+        ArgumentParser() = delete;
+        ~ArgumentParser() = default;
+        ArgumentParser(const ArgumentParser&) = delete;
+        ArgumentParser& operator=(const ArgumentParser&) = delete;
+        ArgumentParser(ArgumentParser&&) = default;
+        ArgumentParser& operator=(ArgumentParser&&) = default;
+
+        /** @brief Contructs Argument object
+         *
+         *  @param argc - the main function's argc passed as is
+         *  @param argv - the main function's argv passed as is
+         *  @return Object constructed
+         */
+        ArgumentParser(int argc, char** argv);
+
+        /** @brief Given an option, returns its argument(optarg)
+         *
+         *  @param opt - command line option string
+         *
+         *  @return argument which is a standard optarg
+         */
+        const std::string& operator[](const std::string& opt);
+
+        /** @brief Displays usage
+         *
+         *  @param argv - the main function's argv passed as is
+         */
+        static void usage(char** argv);
+
+        /** @brief Set to 'true' when an option is passed */
+        static const std::string trueString;
+
+        /** @brief Set to '' when an option is not passed */
+        static const std::string emptyString;
+
+    private:
+        /** @brief Option to argument mapping */
+        std::map<const std::string, std::string> arguments;
+
+        /** @brief Array of struct options as needed by getopt_long */
+        static const option options[];
+
+        /** @brief optstring as needed by getopt_long */
+        static const char* optionStr;
+};
+
+} // namespace ncsi
+} // namespace network
+} // namespace phosphor
+