


 RRRRRRRRDDDDssss((((3333))))                           1111....0000....44445555                            RRRRRRRRDDDDssss((((3333))))
 rrrrrrrrddddttttoooooooollll                                                             rrrrrrrrddddttttoooooooollll
                                 2222000000003333----00007777----22221111



 NNNNAAAAMMMMEEEE
      RRDs - Access rrdtool as a shared module

 SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS
        use RRDs;
        RRDs::error
        RRDs::last ...
        RRDs::info ...
        RRDs::create ...
        RRDs::update ...
        RRDs::graph ...
        RRDs::fetch ...
        RRDs::tune ...

 DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
      CCCCaaaalllllllliiiinnnngggg SSSSeeeeqqqquuuueeeennnncccceeee

      This module accesses rrdtool functionality directly from within perl.
      The arguments to the functions listed in the SYNOPSIS are explained in
      the regular rrdtool documentation. The commandline call

       rrdtool update mydemo.rrd --template in:out N:12:13

      gets turned into

       RRDs::update ("mydemo.rrd", "--template", "in:out", "N:12:13");

      Note that

       --template=in:out

      is also valid.

      EEEErrrrrrrroooorrrr HHHHaaaannnnddddlllliiiinnnngggg

      The RRD functions will not abort your program even when they can not
      make sense out of the arguments you fed them.

      The function RRDs::error should be called to get the error status
      after each function call. If RRDs::error does not return anything then
      the previous function has completed its task successfully.

       use RRDs;
       RRDs::update ("mydemo.rrd","N:12:13");
       my $ERR=RRDs::error;
       die "ERROR while updating mydemo.rrd: $ERR\n" if $ERR;







                                    - 1 -        Formatted:  August 20, 2003






 RRRRRRRRDDDDssss((((3333))))                           1111....0000....44445555                            RRRRRRRRDDDDssss((((3333))))
 rrrrrrrrddddttttoooooooollll                                                             rrrrrrrrddddttttoooooooollll
                                 2222000000003333----00007777----22221111



      RRRReeeettttuuuurrrrnnnn VVVVaaaalllluuuueeeessss

      The functions RRDs::last, RRDs::graph, RRDs::info and RRDs::fetch
      return their findings.

      RRRRRRRRDDDDssss::::::::llllaaaasssstttt returns a single INTEGER representing the last update time.

       $lastupdate = RRDs::last ...

      RRRRRRRRDDDDssss::::::::ggggrrrraaaapppphhhh returns an pointer to an ARRAY containing the x-size and
      y-size of the created gif and results of the PRINT arguments.

       ($averages,$xsize,$ysize) = RRDs::graph ...
       print "Gifsize: ${xsize}x${ysize}\n";
       print "Averages: ", (join ", ", @$averages);

      RRRRRRRRDDDDssss::::::::iiiinnnnffffoooo returns a pointer to a hash. The keys of the hash represent
      the property names of the rrd and the values of the hash are the
      values of the properties.

       $hash = RRDs::info "example.rrd";
       foreach my $key (keys %$hash){
         print "$key = $$hash{$key}\n";
       }

      RRRRRRRRDDDDssss::::::::ffffeeeettttcccchhhh is the most complex of the pack regarding return values.
      There are 4 values. Two normal integers, a pointer to an array and a
      pointer to a array of pointers.

        my ($start,$step,$names,$data) = RRDs::fetch ...
        print "Start:       ", scalar localtime($start), " ($start)\n";
        print "Step size:   $step seconds\n";
        print "DS names:    ", join (", ", @$names)."\n";
        print "Data points: ", $#$data + 1, "\n";
        print "Data:\n";
        foreach my $line (@$data) {
          print "  ", scalar localtime($start), " ($start) ";
          $start += $step;
          foreach my $val (@$line) {
            printf "%12.1f ", $val;
          }
          print "\n";
        }

      See the examples directory for more ways to use this extension.

 NNNNOOOOTTTTEEEE
      If you are manipulating the TZ variable you should also call the
      posixs function tzset to initialize all internal state of the library
      for properly operating in the timezone of your choice.



                                    - 2 -        Formatted:  August 20, 2003






 RRRRRRRRDDDDssss((((3333))))                           1111....0000....44445555                            RRRRRRRRDDDDssss((((3333))))
 rrrrrrrrddddttttoooooooollll                                                             rrrrrrrrddddttttoooooooollll
                                 2222000000003333----00007777----22221111



       use POSIX qw(tzset);
       $ENV{TZ} = 'CET';
       POSIX::tzset();

 AAAAUUUUTTTTHHHHOOOORRRR
      Tobias Oetiker <oetiker@ee.ethz.ch>















































                                    - 3 -        Formatted:  August 20, 2003



