Copy function && Separate function for everything

Program.cs

@@ -1,5 +1,6 @@
 public class Program {
     static void Main(string[] args) {
-        
+        string result = Update.copyEverthingToBackup();
+        Console.WriteLine(result);
     }
 }

Update.cs

@@ -1,21 +1,23 @@
 using System.Diagnostics;
 public class Update {
-    public string homePath { get; set; } = string.Empty;
-    public void getHomePath() {
+    public static string getHomePath() {
+        string homePath = string.Empty;
+
         if(Environment.OSVersion.Platform == PlatformID.Unix) {
             homePath = Environment.GetEnvironmentVariable("HOME");
+            return homePath;
         } else {
-            Console.WriteLine("This script doesn't support your operating system.");
+            throw new ApplicationException("This script doesn't support your operating system.");
         }
     }
 
-    public void startUpdate() {
+    public static void startUpdate() {
         Process process = new Process();
 
         ProcessStartInfo processStartInfo = new ProcessStartInfo();
         //processStartInfo.WindowStyle = ProcessWindowStyle.Hidden;
         processStartInfo.FileName = @"yay";
-        processStartInfo.WorkingDirectory = homePath;
+        processStartInfo.WorkingDirectory = getHomePath();
         //processStartInfo.Arguments = "--color";
         processStartInfo.RedirectStandardOutput = false;
         processStartInfo.RedirectStandardError = false;
@@ -23,5 +25,29 @@ public class Update {
 
         process.StartInfo = processStartInfo;
         process.Start();
+
+        process.StandardInput.WriteLine(" ");
+
+        //shellStream.WriteLine("passwd fadwa");
+        //shellStream.Expect("Enter new password:");
+        //shellStream.WriteLine("fadwa");
+        //shellStream.Expect("Retype new password:");
+        //shellStream.WriteLine("fadwa");
+
+    }
+
+    public static string copyEverthingToBackup() {
+        string fileName = "fstab";
+        string sourcePath = @"/etc/";
+        string targetPath =  getHomePath();
+
+        string sourceFile = System.IO.Path.Combine(sourcePath, fileName);
+        string destFile = System.IO.Path.Combine(targetPath, fileName);
+
+        System.IO.Directory.CreateDirectory(targetPath);
+
+        System.IO.File.Copy(sourceFile, destFile, true);
+
+        return $"Copied {fileName} to {targetPath}";
     }
 }