Class Logger
In: logger.rb
Parent: Object

Methods

<<   add   close   datetime_format   datetime_format=   debug   debug?   error   error?   fatal   fatal?   info   info?   log   new   unknown   warn   warn?  

Included Modules

Severity

Classes and Modules

Module Logger::Severity
Class Logger::Application
Class Logger::Error
Class Logger::Formatter
Class Logger::LogDevice
Class Logger::ShiftingError

Constants

VERSION = "1.2.6"
ProgName = "#{$1}/#{$2}"
SEV_LABEL = %w(DEBUG INFO WARN ERROR FATAL ANY)   Severity label for logging. (max 5 char)

External Aliases

level -> sev_threshold
level= -> sev_threshold=

Attributes

formatter  [RW]  Logging formatter. formattercall is invoked with 4 arguments; severity, time, progname and msg for each log. Bear in mind that time is a Time and msg is an Object that user passed and it could not be a String. It is expected to return a logdevwrite-able Object. Default formatter is used when no formatter is set.
level  [RW]  Logging severity threshold (e.g. Logger::INFO).
progname  [RW]  Logging program name.

Public Class methods

Synopsis

  Logger.new(name, shift_age = 7, shift_size = 1048576)
  Logger.new(name, shift_age = 'weekly')

Args

logdev:The log device. This is a filename (String) or IO object (typically STDOUT, STDERR, or an open file).
shift_age:Number of old log files to keep, or frequency of rotation (daily, weekly or monthly).
shift_size:Maximum logfile size (only applies when shift_age is a number).

Description

Create an instance.

[Source]

# File logger.rb, line 265
  def initialize(logdev, shift_age = 0, shift_size = 1048576)
    @progname = nil
    @level = DEBUG
    @default_formatter = Formatter.new
    @formatter = nil
    @logdev = nil
    if logdev
      @logdev = LogDevice.new(logdev, :shift_age => shift_age,
        :shift_size => shift_size)
    end
  end

Public Instance methods

Dump given message to the log device without any formatting. If no log device exists, return nil.

[Source]

# File logger.rb, line 345
  def <<(msg)
    unless @logdev.nil?
      @logdev.write(msg)
    end
  end

Synopsis

  Logger#add(severity, message = nil, progname = nil) { ... }

Args

severity:Severity. Constants are defined in Logger namespace: DEBUG, INFO, WARN, ERROR, FATAL, or UNKNOWN.
message:The log message. A String or Exception.
progname:Program name string. Can be omitted. Treated as a message if no message and block are given.
block:Can be omitted. Called to get a message string if message is nil.

Return

true if successful, false otherwise.

When the given severity is not high enough (for this particular logger), log no message, and return true.

Description

Log a message if the given severity is high enough. This is the generic logging method. Users will be more inclined to use debug, info, warn, error, and fatal.

Message format: message can be any object, but it has to be converted to a String in order to log it. Generally, inspect is used if the given object is not a String. A special case is an Exception object, which will be printed in detail, including message, class, and backtrace. See msg2str for the implementation if required.

Bugs

  • Logfile is not locked.
  • Append open does not need to lock file.
  • But on the OS which supports multi I/O, records possibly be mixed.

[Source]

# File logger.rb, line 321
  def add(severity, message = nil, progname = nil, &block)
    severity ||= UNKNOWN
    if @logdev.nil? or severity < @level
      return true
    end
    progname ||= @progname
    if message.nil?
      if block_given?
        message = yield
      else
        message = progname
        progname = @progname
      end
    end
    @logdev.write(
      format_message(format_severity(severity), Time.now, progname, message))
    true
  end

Close the logging device.

[Source]

# File logger.rb, line 426
  def close
    @logdev.close if @logdev
  end

[Source]

# File logger.rb, line 210
  def datetime_format
    @default_formatter.datetime_format
  end

Logging date-time format (string passed to strftime).

[Source]

# File logger.rb, line 206
  def datetime_format=(datetime_format)
    @default_formatter.datetime_format = datetime_format
  end

Log a DEBUG message.

See info for more information.

[Source]

# File logger.rb, line 356
  def debug(progname = nil, &block)
    add(DEBUG, nil, progname, &block)
  end

Returns true iff the current severity level allows for the printing of DEBUG messages.

[Source]

# File logger.rb, line 226
  def debug?; @level <= DEBUG; end

Log an ERROR message.

See info for more information.

[Source]

# File logger.rb, line 400
  def error(progname = nil, &block)
    add(ERROR, nil, progname, &block)
  end

Returns true iff the current severity level allows for the printing of ERROR messages.

[Source]

# File logger.rb, line 238
  def error?; @level <= ERROR; end

Log a FATAL message.

See info for more information.

[Source]

# File logger.rb, line 409
  def fatal(progname = nil, &block)
    add(FATAL, nil, progname, &block)
  end

Returns true iff the current severity level allows for the printing of FATAL messages.

[Source]

# File logger.rb, line 242
  def fatal?; @level <= FATAL; end

Log an INFO message.

The message can come either from the progname argument or the block. If both are provided, then the block is used as the message, and progname is used as the program name.

Examples

  logger.info("MainApp") { "Received connection from #{ip}" }
  # ...
  logger.info "Waiting for input from user"
  # ...
  logger.info { "User typed #{input}" }

You‘ll probably stick to the second form above, unless you want to provide a program name (which you can do with Logger#progname= as well).

Return

See add.

[Source]

# File logger.rb, line 382
  def info(progname = nil, &block)
    add(INFO, nil, progname, &block)
  end

Returns true iff the current severity level allows for the printing of INFO messages.

[Source]

# File logger.rb, line 230
  def info?; @level <= INFO; end
log(severity, message = nil, progname = nil, &block)

Alias for add

Log an UNKNOWN message. This will be printed no matter what the logger level.

See info for more information.

[Source]

# File logger.rb, line 419
  def unknown(progname = nil, &block)
    add(UNKNOWN, nil, progname, &block)
  end

Log a WARN message.

See info for more information.

[Source]

# File logger.rb, line 391
  def warn(progname = nil, &block)
    add(WARN, nil, progname, &block)
  end

Returns true iff the current severity level allows for the printing of WARN messages.

[Source]

# File logger.rb, line 234
  def warn?; @level <= WARN; end

[Validate]