# Table of Contents - logger: Ruby Standard Library Documentation

## Classes and Modules

- Logger
  - About the Examples
  - Synopsis
  - Entries
  - Severity
  - Timestamp
  - Message
  - Program Name
  - Log Level
  - Log File Rotation
  - Size-Based Rotation
  - Periodic Rotation
- Logger::Formatter
- Logger::LogDevice
- Logger::Period
- Logger::Severity

## Methods

- ::coerce — Logger::Severity
- ::new — Logger
- ::new — Logger::Formatter
- ::new — Logger::LogDevice
- #<< — Logger
- #add — Logger
- #call — Logger::Formatter
- #close — Logger
- #close — Logger::LogDevice
- #datetime_format — Logger
- #datetime_format= — Logger
- #debug — Logger
- #debug! — Logger
- #debug? — Logger
- #error — Logger
- #error! — Logger
- #error? — Logger
- #fatal — Logger
- #fatal! — Logger
- #fatal? — Logger
- #format_datetime — Logger::Formatter
- #format_message — Logger
- #format_severity — Logger
- #info — Logger
- #info! — Logger
- #info? — Logger
- #level — Logger
- #level= — Logger
- #level_key — Logger
- #level_override — Logger
- #log — Logger
- #msg2str — Logger::Formatter
- #next_rotate_time — Logger::Period
- #previous_period_end — Logger::Period
- #reopen — Logger
- #reopen — Logger::LogDevice
- #sev_threshold — Logger
- #sev_threshold= — Logger
- #unknown — Logger
- #warn — Logger
- #warn! — Logger
- #warn? — Logger
- #with_level — Logger
- #write — Logger::LogDevice