Included Modules
Classes and Modules
Module Logger::SeverityClass 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.
# File logger.rb, line 265
265: def initialize(logdev, shift_age = 0, shift_size = 1048576)
266: @progname = nil
267: @level = DEBUG
268: @default_formatter = Formatter.new
269: @formatter = nil
270: @logdev = nil
271: if logdev
272: @logdev = LogDevice.new(logdev, :shift_age => shift_age,
273: :shift_size => shift_size)
274: end
275: end
Public Instance methods
Dump given message to the log device without any formatting. If no log device exists, return nil.
# File logger.rb, line 345
345: def <<(msg)
346: unless @logdev.nil?
347: @logdev.write(msg)
348: end
349: 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.
# File logger.rb, line 321
321: def add(severity, message = nil, progname = nil, &block)
322: severity ||= UNKNOWN
323: if @logdev.nil? or severity < @level
324: return true
325: end
326: progname ||= @progname
327: if message.nil?
328: if block_given?
329: message = yield
330: else
331: message = progname
332: progname = @progname
333: end
334: end
335: @logdev.write(
336: format_message(format_severity(severity), Time.now, progname, message))
337: true
338: end
Close the logging device.
# File logger.rb, line 426
426: def close
427: @logdev.close if @logdev
428: end
# File logger.rb, line 210
210: def datetime_format
211: @default_formatter.datetime_format
212: end
Returns true iff the current severity level allows for the printing of DEBUG messages.
# File logger.rb, line 226
226: def debug?; @level <= DEBUG; end
Returns true iff the current severity level allows for the printing of ERROR messages.
# File logger.rb, line 238
238: def error?; @level <= ERROR; end
Returns true iff the current severity level allows for the printing of FATAL messages.
# File logger.rb, line 242
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.
# File logger.rb, line 382
382: def info(progname = nil, &block)
383: add(INFO, nil, progname, &block)
384: end
Returns true iff the current severity level allows for the printing of INFO messages.
# File logger.rb, line 230
230: def info?; @level <= INFO; end