refactor: use regexp to get root path

main.go

@@ -1,18 +1,20 @@
 package main
 
 import (
-	"log"
-	"os/exec"
-	"strings"
+	"os"
+	"regexp"
 )
 
-func RootDir() string {
-	cmdOut, err := exec.Command("git", "rev-parse", "--show-toplevel").Output()
-	if err != nil {
-		log.Fatalf("exec.Command: %s", err)
+func RootDir(projectDirName string) string {
+	if projectDirName == "" {
 		return ""
 	}
 
-	rootDir := strings.TrimSpace(string(cmdOut))
-	return rootDir
+	projectName := regexp.MustCompile(`^(.*` + projectDirName + `)`)
+	currentWorkDirectory, _ := os.Getwd()
+	rootPath := projectName.Find([]byte(currentWorkDirectory))
+	if len(rootPath) <= 0 {
+		return ""
+	}
+	return string(rootPath)
 }