check occupied port

Signed-off-by: FTCHD <144691102+FTCHD@users.noreply.github.com>

main.ts

@@ -118,7 +118,8 @@ async function validateInstance() {
 
 async function checkAlreadyRunning() {
     try {
-        const running = await invoke<boolean>('is_rclone_running')
+        const rcPort = 5572
+        const running = await invoke<boolean>('is_rclone_running', { port: rcPort })
         if (running) {
             const confirmed = await ask(
                 'Rclone is already running on this system.\n\nPlease stop it before launching Rclone UI.',

src-tauri/src/lib.rs

@@ -183,7 +183,27 @@ fn get_uid() -> String {
 }
 
 #[tauri::command]
-fn is_rclone_running() -> bool {
+fn is_rclone_running(port: Option<u16>) -> bool {
+
+    if let Some(port) = port {
+        use std::net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr, TcpStream};
+        use std::time::Duration;
+
+        let timeout = Duration::from_millis(200);
+        let addrs = [
+            SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), port),
+            SocketAddr::new(IpAddr::V6(Ipv6Addr::LOCALHOST), port),
+        ];
+
+        for addr in addrs.iter() {
+            if let Ok(stream) = TcpStream::connect_timeout(addr, timeout) {
+                drop(stream);
+                return true;
+            }
+        }
+
+        return false;
+    }
 
     let system = System::new_all();
     for (_pid, process) in system.processes() {