* ext/syslog/lib/syslog/logger.rb: Added Syslog::Logger which was

  ported from the SyslogLogger gem.  [ruby-trunk - Feature #5096]
* NEWS:  ditto.
* test/syslog/test_syslog_logger.rb:  ditto.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@35682 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 174 insertions, 0 deletions

diff --git a/ext/syslog/lib/syslog/logger.rb b/ext/syslog/lib/syslog/logger.rb
new file mode 100644
index 0000000000..10c6b590c6
--- /dev/null
+++ b/ext/syslog/lib/syslog/logger.rb
@@ -0,0 +1,174 @@
+require 'syslog'
+require 'logger'
+
+##
+# Syslog::Logger is a Logger work-alike that logs via syslog instead of to a
+# file.  You can use Syslog::Logger to aggregate logs between multiple
+# machines.
+#
+# By default, Syslog::Logger uses the program name 'ruby', but this can be
+# changed via the first argument to Syslog::Logger.new.
+#
+# NOTE! You can only set the Syslog::Logger program name when you initialize
+# Syslog::Logger for the first time.  This is a limitation of the way
+# Syslog::Logger uses syslog (and in some ways, a limitation of the way
+# syslog(3) works).  Attempts to change Syslog::Logger's program name after
+# the first initialization will be ignored.
+#
+# === Example
+#
+# The following will log to syslogd on your local machine:
+#
+#   require 'syslog/logger'
+#
+#   log = Syslog::Logger.new 'my_program'
+#   log.info 'this line will be logged via syslog(3)'
+#
+# You may need to perform some syslog.conf setup first.  For a BSD machine add
+# the following lines to /etc/syslog.conf:
+#
+#  !my_program
+#  *.*                                             /var/log/my_program.log
+#
+# Then touch /var/log/my_program.log and signal syslogd with a HUP
+# (killall -HUP syslogd, on FreeBSD).
+#
+# If you wish to have logs automatically roll over and archive, see the
+# newsyslog.conf(5) and newsyslog(8) man pages.
+
+class Syslog::Logger
+
+  ##
+  # The version of Syslog::Logger you are using.
+
+  VERSION = '2.0'
+
+  ##
+  # Maps Logger warning types to syslog(3) warning types.
+  #
+  # Messages from ruby applications are not considered as critical as messages
+  # from other system daemons using syslog(3), so most messages are reduced by
+  # one level.  For example, a fatal message for ruby's Logger is considered
+  # an error for syslog(3).
+
+  LEVEL_MAP = {
+    ::Logger::UNKNOWN => Syslog::LOG_ALERT,
+    ::Logger::FATAL   => Syslog::LOG_ERR,
+    ::Logger::ERROR   => Syslog::LOG_WARNING,
+    ::Logger::WARN    => Syslog::LOG_NOTICE,
+    ::Logger::INFO    => Syslog::LOG_INFO,
+    ::Logger::DEBUG   => Syslog::LOG_DEBUG,
+  }
+
+  ##
+  # Returns the internal Syslog object that is initialized when the
+  # first instance is created.
+
+  def self.syslog
+    @@syslog
+  end
+
+  ##
+  # Specifies the internal Syslog object to be used.
+
+  def self.syslog= syslog
+    @@syslog = syslog
+  end
+
+  ##
+  # Builds a methods for level +meth+.
+
+  def self.make_methods meth
+    level = ::Logger.const_get(meth.upcase)
+    eval <<-EOM, nil, __FILE__, __LINE__ + 1
+      def #{meth}(message = nil, &block)
+        add(#{level}, message, &block)
+      end
+
+      def #{meth}?
+        @level <= #{level}
+      end
+    EOM
+  end
+
+  ##
+  # :method: unknown
+  #
+  # Logs a +message+ at the unknown (syslog alert) log level, or logs the
+  # message returned from the block.
+
+  ##
+  # :method: fatal
+  #
+  # Logs a +message+ at the fatal (syslog err) log level, or logs the message
+  # returned from the block.
+
+  ##
+  # :method: error
+  #
+  # Logs a +message+ at the error (syslog warning) log level, or logs the
+  # message returned from the block.
+
+  ##
+  # :method: warn
+  #
+  # Logs a +message+ at the warn (syslog notice) log level, or logs the
+  # message returned from the block.
+
+  ##
+  # :method: info
+  #
+  # Logs a +message+ at the info (syslog info) log level, or logs the message
+  # returned from the block.
+
+  ##
+  # :method: debug
+  #
+  # Logs a +message+ at the debug (syslog debug) log level, or logs the
+  # message returned from the block.
+
+  Logger::Severity::constants.each do |severity|
+    make_methods severity.downcase
+  end
+
+  ##
+  # Log level for Logger compatibility.
+
+  attr_accessor :level
+
+  ##
+  # Fills in variables for Logger compatibility.  If this is the first
+  # instance of Syslog::Logger, +program_name+ may be set to change the logged
+  # program name.
+  #
+  # Due to the way syslog works, only one program name may be chosen.
+
+  def initialize program_name = 'ruby'
+    @level = ::Logger::DEBUG
+
+    @@syslog ||= Syslog.open(program_name)
+  end
+
+  ##
+  # Almost duplicates Logger#add.  +progname+ is ignored.
+
+  def add severity, message = nil, progname = nil, &block
+    severity ||= ::Logger::UNKNOWN
+    @level <= severity and
+      @@syslog.log LEVEL_MAP[severity], '%s', clean(message || block.call)
+    true
+  end
+
+  private
+
+  ##
+  # Clean up messages so they're nice and pretty.
+
+  def clean message
+    message = message.to_s.strip
+    message.gsub!(/\e\[[0-9;]*m/, '') # remove useless ansi color codes
+    return message
+  end
+
+end
+