Table of Contents

Getting Started

Invex.Extensions.Logging.File is a file logger provider for Microsoft.Extensions.Logging. It plugs into the standard logging pipeline alongside the console, debug, and other providers, and writes formatted log entries to rolling files on disk.

Installation

dotnet add package Invex.Extensions.Logging.File

The package targets net10.0, net9.0, net8.0, and netstandard2.0, so it can be used from modern .NET, older .NET (Core) versions, and .NET Framework applications.

Registering the provider

ASP.NET Core / Generic Host

using Invex.Extensions.Logging.File;

var builder = WebApplication.CreateBuilder(args);

builder.Logging.AddFile();

var app = builder.Build();

Console applications (manual LoggerFactory)

using Invex.Extensions.Logging.File;
using Microsoft.Extensions.Logging;

using var loggerFactory = LoggerFactory.Create(logging =>
{
    logging.AddFile();
});

var logger = loggerFactory.CreateLogger<Program>();
logger.LogInformation("Hello from the file logger!");
Important

In buffered mode (the default), entries are written by a background thread. Make sure the logger factory / host is disposed on shutdown so any pending entries are flushed to disk. Hosted apps do this automatically; with a manual LoggerFactory, the using statement above handles it.

What you get out of the box

With no configuration at all, the defaults are:

Behavior Default
Log directory Logs, relative to the current working directory (created if missing)
File name {ApplicationName}.log
Rollover Daily, or when the file reaches 100 MiB — whichever comes first
Retention Oldest rolled-over file deleted once the total reaches 10 GiB
Write mode Buffered (background thread)

A typical Logs directory after a few days looks like:

Logs/
    MyApp.log                  <- active file
    MyApp_260609-084512.log    <- rolled over
    MyApp_260610-091304.log    <- rolled over

Filtering log levels

The file provider does not filter levels itself — it relies on the standard log filtering rules. Use the provider alias File to scope rules to this provider:

{
  "Logging": {
    "LogLevel": {
      "Default": "Information"
    },
    "File": {
      "LogLevel": {
        "Default": "Warning",
        "MyApp.Services": "Information"
      }
    }
  }
}

Next steps

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