change - add default configuration paths (#121)

README.md

@@ -33,7 +33,7 @@ of wireproxy by [@juev](https://github.com/juev).
 
 # Usage
 ```
-./wireproxy -c [path to config]
+./wireproxy [-c path to config]
 ```
 
 ```
@@ -47,6 +47,7 @@ Arguments:
 
   -h  --help        Print help information
   -c  --config      Path of configuration file
+                    Default paths: /etc/wireproxy/wireproxy.conf, $HOME/.config/wireproxy.conf
   -s  --silent      Silent mode
   -d  --daemon      Make wireproxy run in background
   -i  --info        Specify the address and port for exposing health status

cmd/wireproxy/main.go

@@ -22,6 +22,12 @@ import (
 // an argument to denote that this process was spawned by -d
 const daemonProcess = "daemon-process"
 
+// default paths for wireproxy config file
+var default_config_paths = []string {
+    "/etc/wireproxy/wireproxy.conf",
+    os.Getenv("HOME")+"/.config/wireproxy.conf",
+}
+
 var version = "1.0.8-dev"
 
 func panicIfError(err error) {
@@ -51,6 +57,16 @@ func executablePath() string {
 	return programPath
 }
 
+// check if default config file paths exist
+func configFilePath() (string, bool) {
+    for _, path := range default_config_paths {
+        if _, err := os.Stat(path); err == nil {
+            return path, true
+        }
+    }
+    return "", false
+}
+
 func lock(stage string) {
 	switch stage {
 	case "boot":
@@ -177,8 +193,12 @@ func main() {
 	}
 
 	if *config == "" {
-		fmt.Println("configuration path is required")
-		return
+        if path, config_exist := configFilePath(); config_exist {
+            *config = path
+        } else {
+            fmt.Println("configuration path is required")
+            return
+        }
 	}
 
 	if !*daemon {