Fix command executor timeout handling and add detached mode

- Add detached mode for long-running processes via detached=true config
- Fix process termination on timeout using process groups and kill -TERM/-KILL
- Remove double shell wrapping that was breaking command execution
- Track PIDs via wrapper script to enable proper process cleanup
- Flush port messages after timeout to prevent Tortoise MQTT errors
- Update example config to demonstrate detached command usage

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

server/lib/systant/command_executor.ex

@@ -42,7 +42,8 @@ defmodule Systant.CommandExecutor do
           description: cmd["description"],
           trigger: cmd["trigger"],
           allowed_params: cmd["allowed_params"] || [],
-          timeout: cmd["timeout"] || 10
+          timeout: cmd["timeout"] || 10,
+          detached: cmd["detached"] || false
         }
       end)
     else
@@ -115,8 +116,8 @@ defmodule Systant.CommandExecutor do
       # If running as root and this looks like a Wayland command, wrap with sudo
       final_command_with_user = maybe_wrap_with_sudo(final_command_string, command_config)
       
-      # Always wrap in sh -c for shell features (variables, pipes, etc.)
+      # Return the command string directly - we'll handle shell execution in execute_regular_command
-      {:ok, ["sh", "-c", final_command_with_user]}
+      {:ok, final_command_with_user}
     else
       {:error, "Command configuration must be a string"}
     end
@@ -172,18 +173,6 @@ defmodule Systant.CommandExecutor do
     end)
   end
   
-  defp substitute_parameters(command_parts, params) do
-    param_map = build_param_map(params)
-    
-    Enum.map(command_parts, fn part ->
-      case part do
-        "$" <> var_name ->
-          Map.get(param_map, var_name, part)
-        _ ->
-          part
-      end
-    end)
-  end
   
   defp build_param_map(params) do
     # For now, use simple mapping: first param is $SERVICE, $PATH, $PROCESS, $HOST, etc.
@@ -241,66 +230,233 @@ defmodule Systant.CommandExecutor do
   end
   
   defp execute_system_command(final_command, command_config, parsed_command) do
+    is_detached = command_config["detached"] || false
     timeout = (command_config["timeout"] || 10) * 1000  # Convert to milliseconds
-    start_time = System.monotonic_time(:millisecond)
     
     # Build environment for command execution
     env = build_command_environment()
     
+    if is_detached do
+      Logger.info("Executing detached command: #{inspect(final_command)}")
+    else
       Logger.info("Executing system command: #{inspect(final_command)} (timeout: #{timeout}ms)")
+    end
+    
     Logger.debug("Environment PATH: #{Map.get(env, "PATH")}")
     Logger.debug("Environment USER: #{Map.get(env, "USER")}")
     Logger.debug("Environment HOME: #{Map.get(env, "HOME")}")
     Logger.debug("Environment XDG_RUNTIME_DIR: #{Map.get(env, "XDG_RUNTIME_DIR")}")
     
-    try do
+    if is_detached do
-      task = Task.async(fn ->
+      # For detached processes, spawn and immediately return success
-        System.cmd(List.first(final_command), Enum.drop(final_command, 1), 
+      execute_detached_command(final_command, env, parsed_command)
-                   stderr_to_stdout: true, env: env)
+    else
-      end)
+      # For regular processes, wait for completion with timeout
+      execute_regular_command(final_command, env, timeout, parsed_command)
+    end
+  end
   
-      case Task.await(task, timeout) do
+  defp execute_detached_command(command_string, env, parsed_command) do
-        {output, 0} ->
+    try do
-          execution_time = System.monotonic_time(:millisecond) - start_time
+      # Use spawn to start process without waiting
-          Logger.info("Command completed successfully in #{execution_time}ms")
+      port = Port.open({:spawn_executable, "/bin/sh"}, [
+        :binary,
+        :exit_status,
+        args: ["-c", command_string],
+        env: Enum.map(env, fn {k, v} -> {String.to_charlist(k), String.to_charlist(v)} end)
+      ])
+      
+      # Close the port immediately to detach
+      Port.close(port)
+      
+      Logger.info("Detached command started successfully")
       
       {:ok, %{
         request_id: parsed_command.request_id,
         command: parsed_command.trigger,
         status: "success",
-            output: String.trim(output),
+        output: "Command started in detached mode",
-            execution_time: execution_time / 1000.0,
+        detached: true,
         timestamp: DateTime.utc_now() |> DateTime.to_iso8601()
       }}
-          
-        {output, exit_code} ->
-          execution_time = System.monotonic_time(:millisecond) - start_time
-          Logger.warning("Command failed with exit code #{exit_code} in #{execution_time}ms")
-          
-          {:ok, %{
-            request_id: parsed_command.request_id,
-            command: parsed_command.trigger,
-            status: "error",
-            output: String.trim(output),
-            error: "Command exited with code #{exit_code}",
-            execution_time: execution_time / 1000.0,
-            timestamp: DateTime.utc_now() |> DateTime.to_iso8601()
-          }}
-      end
     rescue
       error ->
-        execution_time = System.monotonic_time(:millisecond) - start_time
+        Logger.error("Failed to start detached command: #{inspect(error)}")
-        Logger.error("Command execution failed: #{inspect(error)}")
         
         {:ok, %{
           request_id: parsed_command.request_id,
           command: parsed_command.trigger,
           status: "error",
           output: "",
-          error: "Execution failed: #{inspect(error)}",
+          error: "Failed to start detached command: #{inspect(error)}",
+          timestamp: DateTime.utc_now() |> DateTime.to_iso8601()
+        }}
+    end
+  end
+  
+  defp execute_regular_command(command_string, env, timeout, parsed_command) do
+    start_time = System.monotonic_time(:millisecond)
+    
+    # Wrap the command with PID tracking
+    wrapper_script = """
+    echo "SYSTANT_PID:$$"
+    exec #{command_string}
+    """
+    
+    port = Port.open({:spawn_executable, "/bin/sh"}, [
+      :binary,
+      :exit_status,
+      :stderr_to_stdout,
+      args: ["-c", wrapper_script],
+      env: Enum.map(env, fn {k, v} -> {String.to_charlist(k), String.to_charlist(v)} end)
+    ])
+    
+    # Set up monitoring
+    ref = Port.monitor(port)
+    
+    # Collect output with PID extraction
+    output = collect_port_output_with_pid(port, ref, timeout, "", nil)
+    
+    case output do
+      {:ok, data, exit_status, _pid} ->
+        execution_time = System.monotonic_time(:millisecond) - start_time
+        
+        case exit_status do
+          0 ->
+            Logger.info("Command completed successfully in #{execution_time}ms")
+            
+            {:ok, %{
+              request_id: parsed_command.request_id,
+              command: parsed_command.trigger,
+              status: "success",
+              output: String.trim(data),
               execution_time: execution_time / 1000.0,
               timestamp: DateTime.utc_now() |> DateTime.to_iso8601()
             }}
+            
+          code ->
+            Logger.warning("Command failed with exit code #{code} in #{execution_time}ms")
+            
+            {:ok, %{
+              request_id: parsed_command.request_id,
+              command: parsed_command.trigger,
+              status: "error",
+              output: String.trim(data),
+              error: "Command exited with code #{code}",
+              execution_time: execution_time / 1000.0,
+              timestamp: DateTime.utc_now() |> DateTime.to_iso8601()
+            }}
+        end
+        
+      {:timeout, partial_output, pid} ->
+        execution_time = System.monotonic_time(:millisecond) - start_time
+        
+        # First, close the port to prevent more data
+        try do
+          Port.close(port)
+        rescue
+          _ -> :ok
+        end
+        
+        # Kill the process group if we have a PID
+        if pid do
+          kill_process_group(pid)
+        end
+        
+        # Flush any remaining port messages to prevent them from going to other processes
+        flush_port_messages(port)
+        
+        Logger.error("Command timed out after #{timeout}ms and was terminated")
+        
+        {:ok, %{
+          request_id: parsed_command.request_id,
+          command: parsed_command.trigger,
+          status: "error",
+          output: String.trim(partial_output),
+          error: "Command timed out after #{timeout / 1000} seconds and was terminated",
+          execution_time: execution_time / 1000.0,
+          timestamp: DateTime.utc_now() |> DateTime.to_iso8601()
+        }}
+        
+      {:error, reason} ->
+        execution_time = System.monotonic_time(:millisecond) - start_time
+        Logger.error("Command execution failed: #{inspect(reason)}")
+        
+        {:ok, %{
+          request_id: parsed_command.request_id,
+          command: parsed_command.trigger,
+          status: "error",
+          output: "",
+          error: "Execution failed: #{inspect(reason)}",
+          execution_time: execution_time / 1000.0,
+          timestamp: DateTime.utc_now() |> DateTime.to_iso8601()
+        }}
+    end
+  end
+  
+  
+  defp kill_process_group(pid) when is_integer(pid) do
+    # Kill the entire process group
+    Logger.info("Killing process group for PID #{pid}")
+    System.cmd("kill", ["-TERM", "-#{pid}"], stderr_to_stdout: true)
+    
+    # Give it a moment to terminate gracefully
+    Process.sleep(100)
+    
+    # Force kill if still alive
+    case System.cmd("kill", ["-0", "#{pid}"], stderr_to_stdout: true) do
+      {_, 0} ->
+        Logger.warning("Process #{pid} still alive, sending SIGKILL")
+        System.cmd("kill", ["-KILL", "-#{pid}"], stderr_to_stdout: true)
+      _ ->
+        :ok
+    end
+  end
+  defp kill_process_group(_), do: :ok
+  
+  defp flush_port_messages(port) do
+    receive do
+      {^port, _} ->
+        # Recursively flush more messages
+        flush_port_messages(port)
+    after
+      0 ->
+        # No more messages
+        :ok
+    end
+  end
+  
+  defp collect_port_output_with_pid(port, ref, timeout, acc, pid) do
+    receive do
+      {^port, {:data, data}} ->
+        # Extract PID if we see it in the output
+        {new_pid, cleaned_data} = extract_pid(data, pid)
+        collect_port_output_with_pid(port, ref, timeout, acc <> cleaned_data, new_pid)
+        
+      {^port, {:exit_status, status}} ->
+        # Demonitor to avoid receiving DOWN message
+        Port.demonitor(ref, [:flush])
+        {:ok, acc, status, pid}
+        
+      {:DOWN, ^ref, :port, ^port, reason} ->
+        {:error, reason}
+        
+    after
+      timeout ->
+        # Demonitor to avoid receiving DOWN message after timeout
+        Port.demonitor(ref, [:flush])
+        {:timeout, acc, pid}
+    end
+  end
+  
+  defp extract_pid(data, current_pid) do
+    case Regex.run(~r/SYSTANT_PID:(\d+)\n/, data) do
+      [full_match, pid_str] ->
+        pid = String.to_integer(pid_str)
+        cleaned = String.replace(data, full_match, "")
+        {pid, cleaned}
+      nil ->
+        {current_pid, data}
     end
   end
   

server/systant.toml

@@ -120,11 +120,24 @@ log_all_commands = true
 [[commands.available]]
 name = "screenshot"
 trigger = "screenshot"
-description = "Take a screenshot and save to home directory"
+description = "Take a screenshot and save to ~/Pictures/Screenshots"
-command = "grim /home/ryan/screenshot-$(date +%Y%m%d-%H%M%S).png"
+command = "grim /home/ryan/Pictures/Screenshots/screenshot-$(date +%Y%m%d-%H%M%S).png"
 
 [[commands.available]]
 name = "lock_screen"
 trigger = "lock"
 description = "Lock the screen immediately"
 command = "hyprctl dispatch exec swaylock"
+
+[[commands.available]]
+name = "android_mirror_start"
+trigger = "android_mirror_start"
+description = "Start Android screen mirroring"
+command = "scrcpy --tcpip=luna.home --window-title luna.scrcpy -S --audio-source=playback --audio-dup"
+detached = true
+
+[[commands.available]]
+name = "android_mirror_stop"
+trigger = "android_mirror_stop"
+description = "Stop Android screen mirroring"
+command = "hyprctl clients -j | jq '. | map(select(.title == \"luna.scrcpy\")).[0].pid' | xargs kill"

server/systant.toml.example

@@ -102,6 +102,14 @@ command = "ping"
 allowed_params = ["-c", "4", "8.8.8.8", "google.com", "1.1.1.1"]
 description = "Network connectivity test"
 
+# Example of a detached command for long-running processes
+[[commands.available]]
+trigger = "start_app"
+command = "firefox"
+detached = true  # Don't wait for the process to exit, just launch it
+timeout = 5      # Timeout only applies to launching, not running
+description = "Start Firefox browser (detached)"
+
 [logging]
 level = "info"                                          # debug, info, warn, error
 log_config_changes = true