Move IsFileExists into shadowsocks package as utility.

cmd/shadowsocks-local/local.go

@@ -196,20 +196,6 @@ func enoughOptions(config *ss.Config) bool {
 		config.LocalPort != 0 && config.Password != ""
 }
 
-func isFileExists(path string) (bool, error) {
-	stat, err := os.Stat(path)
-	if err == nil {
-		if stat.Mode()&os.ModeType == 0 {
-			return true, nil
-		}
-		return false, errors.New(path + " exists but is not regular file")
-	}
-	if os.IsNotExist(err) {
-		return false, nil
-	}
-	return false, err
-}
-
 func main() {
 	var configFile string
 	var cmdConfig ss.Config
@@ -223,7 +209,7 @@ func main() {
 
 	flag.Parse()
 
-	exists, err := isFileExists(configFile)
+	exists, err := ss.IsFileExists(configFile)
 	// If no config file in current directory, try search it in the binary directory
 	// Note there's no portable way to detect the binary directory.
 	binDir := path.Dir(os.Args[0])

shadowsocks/util.go

@@ -0,0 +1,20 @@
+package shadowsocks
+
+import (
+	"errors"
+	"os"
+)
+
+func IsFileExists(path string) (bool, error) {
+	stat, err := os.Stat(path)
+	if err == nil {
+		if stat.Mode()&os.ModeType == 0 {
+			return true, nil
+		}
+		return false, errors.New(path + " exists but is not regular file")
+	}
+	if os.IsNotExist(err) {
+		return false, nil
+	}
+	return false, err
+}