feat: add default config fallback

This reverts commit 6021ec89f5.

README.md

@@ -12,7 +12,9 @@ For info that with "EVIOCGRAB" the keyboard events can be consumed exclusively b
 
 ## Configuration
 
-The configuration can be 
+The configuration can be provided by either specifying a config file path via the `-c` parameter. If no parameter is provided, the default config path under `$HOME/.config/UsbMakroBoard.yaml` is used.
+
+Find the config schema in [schemas/config.schema.json](./schemas/config.schema.json) as well as a default config in [config.yaml](./config.yaml).
 
 ## Allowing non-root access to the device
 

src/main.cpp

@@ -7,6 +7,7 @@
 #include <fcntl.h>
 #include <linux/input.h>
 #include <iostream>
+#include <cstdlib>
 #include <spdlog/spdlog.h>
 #include <spdlog/sinks/stdout_sinks.h>
 #include <yaml-cpp/yaml.h>
@@ -57,7 +58,7 @@ std::pair<int, int> mapKeyEventToRowColumn(int keyEventNumber, const std::unorde
 
 std::string getConfigPathFromCliArguments(int argc, char *argv[])
 {
-    std::string configPath = "config.yaml";
+    std::string configPath;
     int opt;
     while ((opt = getopt(argc, argv, "c:")) != -1)
     {
@@ -71,6 +72,18 @@ std::string getConfigPathFromCliArguments(int argc, char *argv[])
             exit(EXIT_FAILURE);
         }
     }
+
+    if (configPath.empty()) {
+        const char *home = std::getenv("HOME");
+        if (home != nullptr) {
+            configPath = std::string(home) + "/.config/usbMakroBoard.yaml";
+        }
+        else {
+            std::cerr << "HOME environment variable is not set. Exiting.\n";
+            exit(EXIT_FAILURE);
+        }
+    }
+    
     return configPath;
 }