Add simulator detect

ETTrace/ETTraceRunner/ConnectivityHelper.swift

@@ -0,0 +1,32 @@
+//
+//  ConnectivityHelper.swift
+//  ETTrace
+//
+//  Created by Noah Martin on 2/27/25.
+//
+
+import Foundation
+
+func isPortInUse(port: Int) -> Bool {
+    let sock = socket(AF_INET, SOCK_STREAM, 0)
+    if sock == -1 {
+        print("Failed to create socket")
+        return false
+    }
+
+    var addr = sockaddr_in()
+    addr.sin_len = UInt8(MemoryLayout<sockaddr_in>.size);
+    addr.sin_family = sa_family_t(AF_INET)
+    addr.sin_port = in_port_t(port).bigEndian
+    addr.sin_addr.s_addr = INADDR_LOOPBACK.bigEndian
+
+    let result = withUnsafePointer(to: &addr) {
+        $0.withMemoryRebound(to: sockaddr.self, capacity: 1) {
+            connect(sock, $0, socklen_t(MemoryLayout<sockaddr_in>.size))
+        }
+    }
+
+    close(sock)
+
+    return result == 0
+}

ETTrace/ETTraceRunner/ProcessSelector.swift

@@ -0,0 +1,62 @@
+//
+//  ProcessSelector.swift
+//  ETTrace
+//
+//  Created by Noah Martin on 2/27/25.
+//
+
+import Foundation
+
+struct RunningProcess {
+  let path: String
+  let pid: Int
+  let bundleID: String?
+}
+
+func trimPath(_ path: String) -> String {
+    let pattern = "/([^/]+\\.app)/"
+    if let range = path.range(of: pattern, options: .regularExpression) {
+        return String(path[range.lowerBound...])
+    }
+    return path
+}
+
+func listRunningProcesses() -> [RunningProcess] {
+  var results: [RunningProcess] = []
+  let numberOfProcesses = proc_listpids(UInt32(PROC_ALL_PIDS), 0, nil, 0) / Int32(MemoryLayout<pid_t>.size)
+  guard numberOfProcesses > 0 else { return [] }
+
+  var pids = [pid_t](repeating: 0, count: Int(numberOfProcesses))
+
+  let result = proc_listpids(UInt32(PROC_ALL_PIDS), 0, &pids, Int32(pids.count * MemoryLayout<pid_t>.size))
+  guard result > 0 else { return [] }
+
+  for pid in pids {
+    if pid == 0 { continue }
+
+    var pathBuffer = [CChar](repeating: 0, count: 4 * 1024)
+
+    let pathResult = proc_pidpath(pid, &pathBuffer, UInt32(pathBuffer.count))
+    if pathResult > 0 {
+      let path = String(cString: pathBuffer)
+      if path.contains("CoreSimulator/Devices/") {
+        let url = URL(fileURLWithPath: path)
+        var bundleID: String? = nil
+        var bundleURL = url
+        while bundleURL.pathComponents.count > 1 {
+          if bundleURL.pathExtension == "app" {
+            break
+          }
+          bundleURL.deleteLastPathComponent()
+        }
+
+        if bundleURL.pathExtension == "app",
+        let bundle = Bundle(url: bundleURL) {
+          bundleID = bundle.bundleIdentifier
+        }
+        results.append(.init(path: trimPath(path), pid: Int(pid), bundleID: bundleID))
+      }
+    }
+  }
+  return results
+}

ETTrace/ETTraceRunner/RunnerHelper.swift

@@ -34,12 +34,29 @@ class RunnerHelper {
     }
 
     func start() async throws {
-        print("Please open the app on the \(useSimulator ? "simulator" : "device")")
-        if !useSimulator {
-            print("Re-run with `--simulator` to connect to the simulator.")
+        if !useSimulator || !isPortInUse(port: Int(PTPortNumber)) {
+          // App is not ready to connect
+          if useSimulator {
+            let running = listRunningProcesses()
+            if !running.isEmpty {
+              print("\(running.count) app\(running.count == 1 ? " was" : "s were") found but \(running.count == 1 ? "it is" : "they are") not running ettrace.")
+              for p in running {
+                if let bundleId = p.bundleID {
+                  print("\tBundle Id: \(bundleId) path: \(p.path)")
+                } else {
+                  print("\tPath: \(p.path)")
+                }
+              }
+            }
+          }
+
+          print("Please open the app on the \(useSimulator ? "simulator" : "device")")
+          if !useSimulator {
+              print("Re-run with `--simulator` to connect to the simulator.")
+          }
+          print("Press return when ready...")
+          _ = readLine()
         }
-        print("Press return when ready...")
-        _ = readLine()
 
         print("Connecting to device.")