class ChupaText::DefaultLogger

The default logger for ChupaText. Logger options are retrieved from environment variables.

Here are environment variables to be used:

## ‘CHUPA_TEXT_LOG_OUTPUT`

It specifies log output.

* `-`: ChupaText outputs to the standard output.
* `+`: ChupaText outputs to the standard error output.
* Others: It is used as file name. ChupaText outputs to the file.

The default is ‘+` (the standard error).

## ‘CHUPA_TEXT_LOG_ROTATION_PERIOD`

It specifies log rotation period.

It is ignored when ‘CHUPA_TEXT_LOG_OUTPUT` is `-` (the standard output) or `+` (the standard error output).

* `daily`: Log file is rotated daily.
* `weekly`: Log file is rotated weekly.
* `monthly`: Log file is rotated monthly.
* Others: Invalid value. It is ignored.

## ‘CHUPA_TEXT_LOG_N_GENERATIONS`

It specifies how many old log files are kept.

It is ignored when (a) `CHUPA_TEXT_LOG_OUTPUT` is `-` (the

standard output) or ‘+` (the standard error output) or (b) `CHUPA_TEXT_LOG_RATATION_PERIOD` is valid value.

The default value is ‘7`.

## ‘CHUPA_TEXT_LOG_LEVEL`

It specifies log verbosity.

The default value is ‘info`.

* `unknown`: ChupaText outputs only unknown messages.
* `fatal`: ChupaText outputs `unknown` level messages and
  unhandleable error messages.
* `error`: ChupaText outputs `fatal` level messages and
  handleable error messages.
* `warn`: ChupaText outputs `error` level messages and warning
   level messages.
* `info`: ChupaText outputs `warn` level messages and generic useful
  information messages.
* `debug`: ChupaText outputs all messages.