Provided by: libschedule-cron-events-perl_1.94-1_all bug

NAME

       Schedule::Cron::Events - take a line from a crontab and find out when events will occur

SYNOPSIS

         use Schedule::Cron::Events;
         my @mon = qw(Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec);

         # a crontab line which triggers an event every 5 minutes
         # initialize the counter with the current time
         my $cron1 = new Schedule::Cron::Events( '*/5 * * * * /bin/foo', Seconds => time() );

         # or initialize it with a date, for example 09:51:13 on 21st June, 2002
         my $cron2 = new Schedule::Cron::Events( '*/5 * * * * /bin/foo', Date => [ 13, 51, 9, 21, 5, 102 ] );

         # you could say this too, to use the current time:
         my $cron = new Schedule::Cron::Events( '*/5 * * * * /bin/foo',  Date => [ ( localtime(time()) )[0..5] ] );

         # find the next execution time
         my ($sec, $min, $hour, $day, $month, $year) = $cron->nextEvent;
         printf("Event will start next at %2d:%02d:%02d on %d %s, %d\n", $hour, $min, $sec, $day, $mon[$month], ($year+1900));

         # find the following occurrence of the job
         ($sec, $min, $hour, $day, $month, $year) = $cron->nextEvent;
         printf("Following event will start at %2d:%02d:%02d on %d %s, %d\n", $hour, $min, $sec, $day, $mon[$month], ($year+1900));

         # reset the counter back to the original date given to new()
         $cron->resetCounter;

         # find out when the job would have last run
         ($sec, $min, $hour, $day, $month, $year) = $cron->previousEvent;
         printf("Last event started at %2d:%02d:%02d on %d %s, %d\n", $hour, $min, $sec, $day, $mon[$month], ($year+1900));

         # see when the job would have next run at a point in time
         $cron->setCounterToDate(0, 18, 1, 26, 9, 85); # that's 26th October, 1985
         ($sec, $min, $hour, $day, $month, $year) = $cron->nextEvent;
         printf("Event did start at %2d:%02d:%02d on %d %s, %d\n", $hour, $min, $sec, $day, $mon[$month], ($year+1900));

         # turn a local date into a Unix time
         use Time::Local;
         my $epochSecs = timelocal($sec, $min, $hour, $day, $month, $year);
         print "...or that can be expressed as " . $epochSecs . " seconds which is " . localtime($epochSecs) . "\n";

       Here is a sample of the output produced by that code:

         Event will start next at  0:45:00 on 28 Aug, 2002
         Following event will start at  0:50:00 on 28 Aug, 2002
         Last event started at  0:40:00 on 28 Aug, 2002
         Event did start at  1:20:00 on 26 Oct, 1985
         ...or that can be expressed as 499134000 seconds which is Sat Oct 26 01:20:00 1985

       Note that results will vary according to your local time and timezone.

DESCRIPTION

       Given a line from a crontab, tells you the time at which cron will next run the line, or
       when the last event occurred, relative to any date you choose. The object keeps that
       reference date internally, and updates it when you call nextEvent() or previousEvent() -
       such that successive calls will give you a sequence of events going forward, or backwards,
       in time.

       Use setCounterToNow() to reset this reference time to the current date on your system, or
       use setCounterToDate() to set the reference to any arbitrary time, or resetCounter() to
       take the object back to the date you constructed it with.

       This module uses Set::Crontab to understand the date specification, so we should be able
       to handle all forms of cron entries.

METHODS

       In the following, DATE_LIST is a list of 6 values suitable for passing to
       Time::Local::timelocal() which are the same as the first 6 values returned by the builtin
       localtime(), namely these 6 numbers in this order

       ·   seconds

           a number 0 .. 59

       ·   minutes

           a number 0 .. 59

       ·   hours

           a number 0 .. 23

       ·   dayOfMonth

           a number 0 .. 31

       ·   month

           a number 0 .. 11 - January is *0*, December is *11*

       ·   year

           the desired year number *minus 1900*

       new( CRONTAB_ENTRY, Seconds => REFERENCE_TIME, Date => [ DATE_LIST ] )
           Returns a new object for the specified line from the crontab. The first 5 fields of
           the line are actually parsed by Set::Crontab, which should be able to handle the
           original crontab(5) ranges as well as Vixie cron ranges and the like. It's up to you
           to supply a valid line - if you supply a comment line, an environment variable setting
           line, or a line which does not seem to begin with 5 fields (e.g. a blank line), this
           method returns undef.

           Give either the Seconds option or the Date option, not both.  Supply a six-element
           array (as described above) to specify the date at which you want to start.
           Alternatively, the reference time is the number of seconds since the epoch for the
           time you want to start looking from.

           If neither of the 'Seconds' and 'Date' options are given we use the current time().

       resetCounter()
           Resets the object to the state when created (specifically resetting the internal
           counter to the initial date provided)

       nextEvent()
           Returns a DATE_LIST for the next event following the current reference time.  Updates
           the reference time to the time of the event.

       previousEvent()
           Returns a DATE_LIST for the last event preceding the current reference time.  Updates
           the reference time to the time of the event.

       setCounterToNow()
           Sets the reference time to the current time.

       setCounterToDate( DATE_LIST )
           Sets the reference time to the time given, specified in seconds since the epoch.

       commandLine()
           Returns the string that is the command to be executed as specified in the crontab -
           i.e. without the leading date specification.

ERROR HANDLING

       If something goes wrong the general approach is to raise a fatal error with confess() so
       use eval {} to trap these errors. If you supply a comment line to the constructor then
       you'll simply get back undef, not a fatal error. If you supply a line like 'foo bar */15
       baz qux /bin/false' you'll get a confess().

DEPENDENCIES

       Set::Crontab, Time::Local, Carp. Date::Manip is no longer required thanks to B Paulsen.

MAINTENANCE

       Since January 2012 maintained by Petya Kohts (petya.kohts at gmail.com)

COPYRIGHT

       Copyright 2002 P Kent

       This library is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself.