Provided by: libparanoid-perl_0.34-1_all bug

NAME

       Paranoid::Log - Log Functions

VERSION

       $Id: Log.pm,v 0.14 2010/06/03 19:03:32 acorliss Exp $

SYNOPSIS

         use Paranoid::Log;

         clearLogDist();
         initLogDist();

         $rv = enableFacility($name, $facility, $logLevel, $scope, @args);
         $rv = disableFacility($name);

         $rv = plog($severity, $message);
         $rv = psyslog($severity, $message);

         # The following functions are not exported by default
         clearLogDist();
         initLogDist();
         $timeStamp = ptimestamp();

DESCRIPTION

       This module provides a unified interface and distribution for multiple logging mediums.
       By calling one function (plog) you can have that message stored in multiple mediums
       depending on what you've enabled at what severities.  For instance, you could have a
       critical message not only automatically logged in a log file and syslog, but it could also
       generate an e-mail.

       You can also use your own logging facility modules as long as you adhere to the expected
       API (detailed below).  Just pass the name of the module as the facility in enableFacility.

SYMBOL TAG SETS

       By default, only the following are exported:

         enableFacility
         disableFacility
         plog
         psyslog

       You can get everything using :all, including:

         clearLogDist
         initLogDist
         ptimestamp

LOGGING FACILITIES

       Each logging facility is implemented as separate module consisting of non-exported
       functions with conform to a a consistent API.  Each facility module must have the
       following functions:

         Function        Description
         ------------------------------------------------------
         init            Called when module first loaded
         remove          Removes a named instance of the facility
         log             Logs the passed message
         dump            Dumps internal information

       The init function is only called once -- the first time the module is used and accessed.

       The remove function allows you to remove a specific named instance of the logging facility
       from use.

       The log function is used to actually log an entry into the facility.

       The dump function is used to dump pertinent internal data on the requested named instance.
       This is primarily intended for use with facilities like the log buffer, in which case it
       dumps the contents of the named buffer.  Other uses for this is left to the developer of
       individual facility modules.

SUBROUTINES/METHODS

   clearLogDist
         clearLogDist();

       This empties all enabled loggers from the distribution processor.  It doesn't erase any
       named logging facilities already put into place, simply takes out of the distribution
       system so no further log entries will be processed.

       This can be used to temporarily halt all logging.

   initLogDist
         initLogDist();

       This goes through the list of named loggers and sets up the distribution processor to feed
       them the applicable log entries as they come in.

       This can be used to re-enable logging.

   enableFacility
         $rv = enableFacility($name, $facility, $logLevel, $scope, @args);

       This function enables the specified logging facility at the specified levels.  Each
       facility (or permutation of) is associated with an arbitrary name.  This name can be used
       to bypass log distribution and log only in the named facility.

       The following facilities are available within Paranoid:

         facility        description
         =====================================================
         stderr          prints messages to STDERR
         buffer          stores messages in a named buffer
         file            prints messages to a file
         syslog          sends message to the syslog daemon
         email           sends message to an e-mail recipient

       If you have your own custom facility that complies with the Paranoid::Log calling
       conventions you can pass this the name of the module (for example, Log::Foo).  The first
       letter of the module will always be uppercased before attempting to load it.

       Log levels are modeled after syslog:

         log level       description
         =====================================================
         emerg, panic,   system is unusable
         emergency
         alert           action must be taken immediately
         crit, critical  critical conditions
         err, error      error conditions
         warn, warning   warning conditions
         notice          normal but significant conditions
         info            informational
         debug           debug-level messages

       If omitted level defaults to 'notice'.

       Scope is defined with the following characters:

         character       definition
         =====================================================
         =               log only messages at this severity
         +               log only messages at this severity
                         or higher
         -               log only messages at this severity
                         or lower
         !               log at all levels but this severity

       If omitted scope defaults to '+'.

       Only the first two arguments are mandatory.  What you put into the @args, and whether you
       need it at all, will depend on the facility you're using.  The facilities provided
       directly by Paranoid are as follows:

         facility        arguments
         =====================================================
         stderr          none
         buffer          bufferSize (optional)
         file            filename
         syslog          none
         email           mailhost, recipient, sender (optional),
                         subject (optional)

   disableFacility
         $rv = disableFacility($name);

       Removes the specified logging facility from the configuration and re-initializes the
       distribution processor.

   plog
         $rv = plog($severity, $message);

       This call logs the passed message to all facilities enabled at the specified log level.

   ptimestamp
         $ts = ptimestamp();

       This function returns a syslog-style timestamp string for the current time.  You can
       optionally give it a value as returned by time() and the stamp will be for that timme.

   psyslog
         $rv = psyslog($severity, $message);

       This function's name may be a bit misleading.  This does not cause the message to be
       syslogged (that's the duty of the syslog facility), but rather the message is logged in a
       syslog-style format according to the following template:

         {timestamp} {hostname} {process}[{pid}]: {message}

       You may want to use this if you're using, say, a file logging mechanism but you still want
       the logs in a syslog-styled format.  More often than not, though, you do not want to use
       this function.

DEPENDENCIES

       o   Paranoid::Debug

       o   Paranoid::Input

       o   Paranoid::Module

EXAMPLES

       The following example provides the following behavior:  debug messages go to a file,
       notice & above messages go to syslog, and critical and higher messages also go to console
       and e-mail.

         # Set up the logging facilities
         enableFacility("debug", "file", "debug", "=",
           "/var/log/myapp-debug.log");
         enableFacility("daemon", "syslog", "notice", "+", "myapp");
         enableFacility("console-err", "stderr", "critical", "+");
         enableFacility("smtp-err", "email", "critical", "+",
           "localhost", "root\@localhost", "myapp\@localhost",
           "MyApp Critical Alert");

         # Log some messages
         #
         # Since this is only going to the debug log, we'll use psyslog
         # so we get the timestamps, etc.
         psyslog("debug", "Starting application");

         # Log a notification
         plog("notice", "Uh, something happened...");

         # Log a critical error
         plog("emerg", "Ack! <choke... silence>");

SEE ALSO

       o   Paranoid::Log::Buffer

       o   Paranoid::Log::Email

       o   Paranoid::Log::File

       o   Paranoid::Log::Syslog

BUGS AND LIMITATIONS

AUTHOR

       Arthur Corliss (corliss@digitalmages.com)

LICENSE AND COPYRIGHT

       This software is licensed under the same terms as Perl, itself.  Please see
       http://dev.perl.org/licenses/ for more information.

       (c) 2005, Arthur Corliss (corliss@digitalmages.com)