# File Appender

The file appender writes log events to a file. It supports an optional maximum file size, and will keep a configurable number of backups. When using the file appender, you should also call logger.shutdown() when your application terminates, to ensure that any remaining asynchronous writes have finished. Although the file appender uses the streamroller library, this is included as a dependency of ts-log-debug so you do not need to include it yourself.

# Configuration

  • type - file
  • filename - string - the path of the file where you want your logs written.
  • maxLogSize - integer (optional) - the maximum size (in bytes) for the log file. If not specified, then no log rolling will happen.
  • backups - integer (optional, default value = 5) - the number of old log files to keep during log rolling.
  • layout - (optional, defaults to basic layout) - see layouts

Any other configuration parameters will be passed to the underlying streamroller implementation (see also node.js core file streams):

  • encoding - string (default “utf-8”)
  • mode - integer (default 0644)
  • flags - string (default ‘a’)
  • compress - boolean (default false) - compress the backup files during rolling (backup files will have .gz extension)

# Example

import {Logger} from "@tsed/logger";

const logger = new Logger("loggerName");

logger.appenders.set("everything", {
    type: 'file', 
    filename: 'all-the-logs.log'
});

logger.debug('I will be logged in all-the-logs.log');
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This example will result in a single log file (all-the-logs.log) containing the log messages.

# Example with log rolling (and compressed backups)

import {Logger} from "@tsed/logger";

const logger = new Logger("loggerName");

logger.appenders.set("everything", {
    type: 'file', 
    filename: 'all-the-logs.log',
    maxLogSize: 10485760,
    backups: 3,
    compress: true
});
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This will result in one current log file (all-the-logs.log). When that reaches 10Mb in size, it will be renamed and compressed to all-the-logs.log.1.gz and a new file opened called all-the-logs.log. When all-the-logs.log reaches 10Mb again, then all-the-logs.log.1.gz will be renamed to all-the-logs.log.2.gz, and so on.

# Example with date rolling

import { Logger } from 'ts-log-debug';
export const logger = new Logger('Log Example');

logger.appenders
.set('file', {
  type: 'file',
  filename: `${__dirname}/../logs/myfile.log`,
  pattern: '.yyyy-MM-dd'
});``
``
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