create folder "received" if it doesnt exist

src/main.rs

@@ -233,6 +233,10 @@ fn main() {
 
 
     println!("Received all packets, writing to file");
+
+    //create folder "received" if it does not exist
+    std::fs::create_dir_all("received").expect("Failed to create directory");
+
     //write packets to file
     let mut file = std::fs::File::create("received/".to_string()+filename).expect("Failed to create file");
     for i in 0..packets.len() {