Improve cxxopts usage to avoid segfaults

src/electricity-logger/main.cpp

@@ -10,7 +10,26 @@
 #include <stdexcept>
 #include <string>
 
-std::optional<cxxopts::ParseResult> ExtractArgs(int argc, char ** argv)
+struct CommandlineParameters
+{
+    CommandlineParameters(std::string const & serialDevicePath, std::string const & databaseConnectionString)
+     : DeviceType(serialDevicePath), DatabaseConnectionString(databaseConnectionString) { };
+
+    std::string DeviceType;
+    std::string DatabaseConnectionString;
+};
+
+std::optional<std::string> TryGetStringArgument(cxxopts::ParseResult const & parseResult, std::string const & name)
+{
+    if(!parseResult.contains(name))
+    {
+        return {};
+    }
+
+    return parseResult[name].as_optional<std::string>();
+}
+
+std::optional<CommandlineParameters> TryGetCommandlineArguments(int argc, char ** argv)
 {
     cxxopts::Options options(
         "electricity-logger",
@@ -24,22 +43,25 @@ std::optional<cxxopts::ParseResult> ExtractArgs(int argc, char ** argv)
         "Path to the sqlite3 database file",
         cxxopts::value<std::string>());
 
-    if(argc == 1)
-    {
-        std::cout << options.help() << std::endl;
-        return {};
-    }
-
     try
     {
-        auto const parsed = options.parse(argc, argv);
+        auto const parseResult = options.parse(argc, argv);
-        return parsed;
+        auto const serialDevicePath = TryGetStringArgument(parseResult, "serial-device");
+        auto const databaseConnectionString = TryGetStringArgument(parseResult, "connection-string");
+
+        if(serialDevicePath.has_value() && databaseConnectionString.has_value())
+        {
+            return CommandlineParameters(serialDevicePath.value(), databaseConnectionString.value());
+        }
     }
     catch(cxxopts::exceptions::exception const & e)
     {
         spdlog::error(e.what());
         return {};
     }
+
+    std::cout << options.help() << std::endl;
+    return {};
 }
 
 DSMR::Data ReadData(std::string const & devicePath)
@@ -100,18 +122,15 @@ DSMR::Data ReadData(std::string const & devicePath)
 
 int main(int argc, char ** argv)
 {
-    auto const maybeArgs = ExtractArgs(argc, argv);
+    auto const parameters = TryGetCommandlineArguments(argc, argv);
-    if(!maybeArgs.has_value())
+    if(!parameters.has_value())
     {
         return 1;
     }
 
-    auto const & args = maybeArgs.value();
+    auto const data = ReadData(parameters->DeviceType);
 
-    auto const data = ReadData(args["serial-device"].as<std::string>());
+    Database db(parameters->DatabaseConnectionString);
-
-    auto const connectionStringValue = args["connection-string"].as<std::string>();
-    Database db(connectionStringValue);
     db.Insert(data, std::time(nullptr));
 
     return 0;

src/solar-logger/main.cpp

@@ -21,7 +21,43 @@ namespace detail
     }
 }
 
-std::optional<cxxopts::ParseResult> ExtractArgs(int argc, char ** argv)
+struct CommandlineParameters
+{
+    CommandlineParameters(
+        std::string const & deviceType,
+        std::string const & deviceUrl,
+        unsigned const deviceFetchTimeOut,
+        std::string const & databaseConnectionString)
+     : DeviceType(deviceType), DeviceUrl(deviceUrl), DeviceFetchTimeOut(deviceFetchTimeOut),
+       DatabaseConnectionString(databaseConnectionString) { };
+
+    std::string DeviceType;
+    std::string DeviceUrl;
+    unsigned DeviceFetchTimeOut;
+    std::string DatabaseConnectionString;
+};
+
+std::optional<std::string> TryGetStringArgument(cxxopts::ParseResult const & parseResult, std::string const & name)
+{
+    if(!parseResult.contains(name))
+    {
+        return {};
+    }
+
+    return parseResult[name].as_optional<std::string>();
+}
+
+std::optional<unsigned> TryGetUnsignedArgument(cxxopts::ParseResult const & parseResult, std::string const & name)
+{
+    if(!parseResult.contains(name))
+    {
+        return {};
+    }
+
+    return parseResult[name].as_optional<unsigned>();
+}
+
+std::optional<CommandlineParameters> TryGetCommandlineArguments(int argc, char ** argv)
 {
     cxxopts::Options options(
         "solar-logger",
@@ -49,14 +85,30 @@ std::optional<cxxopts::ParseResult> ExtractArgs(int argc, char ** argv)
 
     try
     {
-        auto const parsed = options.parse(argc, argv);
+        auto const parseResult = options.parse(argc, argv);
-        return parsed;
+        auto const deviceType = TryGetStringArgument(parseResult, "type");
+        auto const deviceUrl = TryGetStringArgument(parseResult, "url");
+        auto const deviceFetchTimeOut = TryGetUnsignedArgument(parseResult, "timeout");
+        auto const databaseConnectionString = TryGetStringArgument(parseResult, "connection-string");
+
+        if(deviceType.has_value() && deviceUrl.has_value() && deviceFetchTimeOut.has_value()
+           && databaseConnectionString.has_value())
+        {
+            return CommandlineParameters(
+                deviceType.value(),
+                deviceUrl.value(),
+                deviceFetchTimeOut.value(),
+                databaseConnectionString.value());
+        }
     }
     catch(cxxopts::exceptions::exception const & e)
     {
         spdlog::error(e.what());
         return {};
     }
+
+    std::cout << options.help() << std::endl;
+    return {};
 }
 
 std::optional<std::string> FetchDataFromURL(const std::string & url, const unsigned int timeout)
@@ -97,21 +149,19 @@ std::optional<std::string> FetchDataFromURL(const std::string & url, const unsig
 
 int main(int argc, char ** argv)
 {
-    auto const maybeArgs = ExtractArgs(argc, argv);
+    auto const parameters = TryGetCommandlineArguments(argc, argv);
-    if(!maybeArgs.has_value())
+    if(!parameters.has_value())
     {
         return 1;
     }
 
-    auto const & args = maybeArgs.value();
+    Database db(parameters->DatabaseConnectionString);
-
-    Database db(args["connection-string"].as<std::string>());
     auto const now = std::time(nullptr);
-    auto const resourceType = args["type"].as<std::string>();
+    auto const resourceType = parameters->DeviceType;
 
     if(resourceType == "Zeverlution")
     {
-        auto const webResource = FetchDataFromURL(args["url"].as<std::string>(), args["timeout"].as<unsigned>());
+        auto const webResource = FetchDataFromURL(parameters->DeviceUrl, parameters->DeviceFetchTimeOut);
         if(!webResource.has_value())
         {
             return -1;
@@ -136,7 +186,7 @@ int main(int argc, char ** argv)
     }
     else if(resourceType == "Envoy")
     {
-        auto const webResource = FetchDataFromURL(args["url"].as<std::string>(), args["timeout"].as<unsigned>());
+        auto const webResource = FetchDataFromURL(parameters->DeviceUrl, parameters->DeviceFetchTimeOut);
         if(!webResource.has_value())
         {
             return -1;