> For the complete documentation index, see [llms.txt](https://vostok.gitbook.io/logging/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://vostok.gitbook.io/logging/prototype/implementations/filelog.md).
# FileLog
A log which outputs events to a file.
### Set Up
Include `Logging.File` library in project:
```csharp
using Vostok.Logging.File;
```
An `ILog` is created using the `FileLog`:
```csharp
var log = new FileLog(
new FileLogSettings { FilePath = "log.txt" });
```
Create logs:
```csharp
log.Info("1");
log.Debug("2");
log.Warn("3");
```
Use `Flush` or `FlushAsync` to ensure that logged events are written to file:
```csharp
FileLog.FlushAll();
```
Configure the log. For example, change the file name. Let it contain the current time:
```csharp
ILog flog = new FileLog(new FileLogSettings
{
FilePath = Path.Combine($"{DateTime.Now:yyyy-MM-dd.HH-mm-ss}.log")
});
```
Choose enabled log levels. Only messages of these levels will be written to the file:
```csharp
ILog flog = new FileLog(new FileLogSettings
{
FilePath = Path.Combine($"{DateTime.Now:yyyy-MM-dd.HH-mm-ss}.log"),
EnabledLogLevels = new [] {LogLevel.Error, LogLevel.Fatal},
});
```
Change encoding:
```csharp
ILog flog = new FileLog(new FileLogSettings
{
FilePath = Path.Combine($"{DateTime.Now:yyyy-MM-dd.HH-mm-ss}.log"),
EnabledLogLevels = new [] {LogLevel.Error, LogLevel.Fatal},
Encoding = Encoding.BigEndianUnicode
});
```
See the section about [Advanced Usage](/logging/prototype/advanced-usage.md) for samples of settings usage.
### Configurations
The above is an example of how to configure a log file from code. However, this is not the only way to build this process.
There are two ways to configure Vostok's FileLog:
* create settings file;
* set settings provider.
```csharp
// configure from code — settings instance
var log1 = new FileLog(new FileLogSettings());
// configure from code — settings instance provider
var log2 = new FileLog(() => new FileLogSettings());
// configure from file
var log3 = new FileLog(new JsonFileSource("log3.json"));
```
Sample configuration file :
```
*тут я не умею, наверное*
```
### Settings
These parameters are adjusted in `FileLogSettings`:
| Parameters | Description |
| ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------- |
| FilePath
| Path to the log file.
|
| OutputTemplate
| Used to render log messages.
|
| FormatProvider
| If specified, this IFormatProvider will be used when formatting log property values. |
| FileOpenMode
| Specifies the way to treat an existing log file: append (default) or rewrite. |
| RollingStrategy
| An optional rolling strategy (disabled by default). |
| Encoding
| Output text encoding (UTF-8 by default). |
| OutputBufferSize
| Output buffer size, in bytes (64K by default). |
| EnabledLogLevels
| A whitelist of enabled LogLevels. |
| EventsQueueCapacity
| Capacity of the internal log events queue. |
| EventsBufferCapacity
| Specifies how many log events are processed in one iteration for each file. |
| FileSettingsUpdateCooldown
| Cooldown for enforcing file-related settings (name, rolling strategy, buffer size, etc.). |