ArgumentParser for fan control

Parses arguments for phosphor-fan-control.

The header file is in the base directory of the repository
and can be common to all fan applications.  The cpp file
needs to be in the subdirectory of the application that uses
it, in this case control.

Change-Id: I93dba60daf8f78667df970ab47ec018d90a8c14f
Signed-off-by: Matt Spinler <spinler@us.ibm.com>

2 files changed, 135 insertions, 0 deletions

diff --git a/argument.hpp b/argument.hpp
new file mode 100644
index 0000000..c314006
--- /dev/null
+++ b/argument.hpp
@@ -0,0 +1,45 @@
+#pragma once
+
+#include <getopt.h>
+#include <map>
+#include <string>
+
+namespace phosphor
+{
+namespace fan
+{
+namespace util
+{
+
+/**
+ * Parses command line arguments.
+ * This header can be used by all fan applications, while
+ * the .cpp will need to be implemented by each of them.
+ */
+class ArgumentParser
+{
+    public:
+        ArgumentParser(int argc, char** argv);
+        ArgumentParser() = delete;
+        ArgumentParser(const ArgumentParser&) = delete;
+        ArgumentParser(ArgumentParser&&) = default;
+        ArgumentParser& operator=(const ArgumentParser&) = delete;
+        ArgumentParser& operator=(ArgumentParser&&) = default;
+        ~ArgumentParser() = default;
+        const std::string& operator[](const std::string& opt);
+
+        static void usage(char** argv);
+
+        static constexpr auto true_string = "true";
+        static const std::string empty_string;
+
+    private:
+        std::map<const std::string, std::string> arguments;
+
+        static const option options[];
+        static const char* optionstr;
+};
+
+}
+}
+}
diff --git a/control/argument.cpp b/control/argument.cpp
new file mode 100644
index 0000000..2852dee
--- /dev/null
+++ b/control/argument.cpp
@@ -0,0 +1,90 @@
+/**
+ * Copyright © 2017 IBM Corporation
+ *
+ * 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.
+ */
+#include <iostream>
+#include <iterator>
+#include <algorithm>
+#include "argument.hpp"
+
+namespace phosphor
+{
+namespace fan
+{
+namespace util
+{
+
+ArgumentParser::ArgumentParser(int argc, char** argv)
+{
+    auto option = 0;
+    while (-1 != (option = getopt_long(argc, argv, optionstr, options, NULL)))
+    {
+        if ((option == '?') || (option == 'h'))
+        {
+            usage(argv);
+            exit(-1);
+        }
+
+        auto i = &options[0];
+        while ((i->val != option) && (i->val != 0))
+        {
+            ++i;
+        }
+
+        if (i->val)
+        {
+            arguments[i->name] = (i->has_arg ? optarg : true_string);
+        }
+    }
+}
+
+const std::string& ArgumentParser::operator[](const std::string& opt)
+{
+    auto i = arguments.find(opt);
+    if (i == arguments.end())
+    {
+        return empty_string;
+    }
+    else
+    {
+        return i->second;
+    }
+}
+
+void ArgumentParser::usage(char** argv)
+{
+    std::cerr << "Usage: " << argv[0] << " [options]\n";
+    std::cerr << "Options:\n";
+    std::cerr << "    --help               Print this menu\n";
+    std::cerr << "    --init               Sets fans to full speed, delays, exits\n";
+    std::cerr << "    --control            Start fan control algorithm\n";
+    std::cerr << std::flush;
+}
+
+const option ArgumentParser::options[] =
+{
+    { "init",    no_argument,  NULL,   'i' },
+    { "control",  no_argument,  NULL,   'c' },
+    { "help",   no_argument,        NULL,   'h' },
+    { 0, 0, 0, 0},
+};
+
+const char* ArgumentParser::optionstr = "ich?";
+
+const std::string ArgumentParser::empty_string = "";
+
+}
+}
+}
+// vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4