# Logging Logging has come to Terminal.Gui! You can now enable comprehensive logging of the internals of the libray. This can help diagnose issues with specific terminals, keyboard cultures and/or operating system specific issues. To enable file logging you should set the static property `Logging.Logger` to an instance of `Microsoft.Extensions.Logging.ILogger`. If your program already uses logging you can provide a shared instance or instance from Dependency Injection (DI). Alternatively you can create a new log to ensure only Terminal.Gui logs appear. Any logging framework will work (Serilog, NLog, Log4Net etc) but you should ensure you only log to File or UDP etc (i.e. not to console!). ## Worked example with Serilog to file Here is an example of how to add logging of Terminal.Gui internals to your program using Serilog file log. Add the Serilog dependencies: ``` dotnet add package Serilog dotnet add package Serilog.Sinks.File dotnet add package Serilog.Extensions.Logging ``` Create a static helper function to create the logger and store in `Logging.Logger`: ```csharp Logging.Logger = CreateLogger(); static ILogger CreateLogger() { // Configure Serilog to write logs to a file Log.Logger = new LoggerConfiguration() .MinimumLevel.Verbose() // Verbose includes Trace and Debug .WriteTo.File("logs/logfile.txt", rollingInterval: RollingInterval.Day) .CreateLogger(); // Create a logger factory compatible with Microsoft.Extensions.Logging using var loggerFactory = LoggerFactory.Create(builder => { builder .AddSerilog(dispose: true) // Integrate Serilog with ILogger .SetMinimumLevel(LogLevel.Trace); // Set minimum log level }); // Get an ILogger instance return loggerFactory.CreateLogger("Global Logger"); } ``` This will create logs in your executables directory (e.g.`\bin\Debug\net8.0`). Example logs: ``` 2025-02-15 13:36:48.635 +00:00 [INF] Main Loop Coordinator booting... 2025-02-15 13:36:48.663 +00:00 [INF] Creating NetOutput 2025-02-15 13:36:48.668 +00:00 [INF] Creating NetInput 2025-02-15 13:36:48.671 +00:00 [INF] Main Loop Coordinator booting complete 2025-02-15 13:36:49.145 +00:00 [INF] Run 'MainWindow(){X=0,Y=0,Width=0,Height=0}' 2025-02-15 13:36:49.163 +00:00 [VRB] Mouse Interpreter raising ReportMousePosition 2025-02-15 13:36:49.165 +00:00 [VRB] AnsiResponseParser handled as mouse '[<35;50;23m' 2025-02-15 13:36:49.166 +00:00 [VRB] MainWindow triggered redraw (NeedsDraw=True NeedsLayout=True) 2025-02-15 13:36:49.167 +00:00 [INF] Console size changes from '{Width=0, Height=0}' to {Width=120, Height=30} 2025-02-15 13:36:49.859 +00:00 [VRB] AnsiResponseParser releasing ' ' 2025-02-15 13:36:49.867 +00:00 [VRB] MainWindow triggered redraw (NeedsDraw=True NeedsLayout=True) 2025-02-15 13:36:50.857 +00:00 [VRB] MainWindow triggered redraw (NeedsDraw=True NeedsLayout=True) 2025-02-15 13:36:51.417 +00:00 [VRB] MainWindow triggered redraw (NeedsDraw=True NeedsLayout=True) 2025-02-15 13:36:52.224 +00:00 [VRB] Mouse Interpreter raising ReportMousePosition 2025-02-15 13:36:52.226 +00:00 [VRB] AnsiResponseParser handled as mouse '[<35;51;23m' 2025-02-15 13:36:52.226 +00:00 [VRB] Mouse Interpreter raising ReportMousePosition 2025-02-15 13:36:52.226 +00:00 [VRB] AnsiResponseParser handled as mouse '[<35;52;23m' 2025-02-15 13:36:52.226 +00:00 [VRB] Mouse Interpreter raising ReportMousePosition 2025-02-15 13:36:52.226 +00:00 [VRB] AnsiResponseParser handled as mouse '[<35;53;23m' ... 2025-02-15 13:36:52.846 +00:00 [VRB] Mouse Interpreter raising ReportMousePosition 2025-02-15 13:36:52.846 +00:00 [VRB] AnsiResponseParser handled as mouse '[<35;112;4m' 2025-02-15 13:36:54.151 +00:00 [INF] RequestStop '' 2025-02-15 13:36:54.151 +00:00 [VRB] AnsiResponseParser handled as keyboard '[21~' 2025-02-15 13:36:54.225 +00:00 [INF] Input loop exited cleanly ``` ## Metrics If you are finding that the UI is slow or unresponsive - or are just interested in performance metrics. You can see these by instaling the `dotnet-counter` tool and running it for your process. ``` dotnet tool install dotnet-counters --global ``` ``` dotnet-counters monitor -n YourProcessName --counters Terminal.Gui ``` Example output: ``` Press p to pause, r to resume, q to quit. Status: Running Name Current Value [Terminal.Gui] Drain Input (ms) Percentile 50 0 95 0 99 0 Invokes & Timers (ms) Percentile 50 0 95 0 99 0 Iteration (ms) Percentile 50 0 95 1 99 1 Redraws (Count) 9 ``` Metrics figures issues such as: - Your console constantly being refreshed (Redraws) - You are blocking main thread with long running Invokes / Timeout callbacks (Invokes & Timers)