RRDs(3)                             rrdtool                            RRDs(3)



[1mNAME[0m
       RRDs - Access rrdtool as a shared module

[1mSYNOPSIS[0m
         use RRDs;
         RRDs::error
         RRDs::last ...
         RRDs::info ...
         RRDs::create ...
         RRDs::update ...
         RRDs::graph ...
         RRDs::fetch ...
         RRDs::tune ...

[1mDESCRIPTION[0m
       [1mCalling Sequence[0m

       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.

       [1mError Handling[0m

       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;

       [1mReturn Values[0m

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

       [1mRRDs::last [22mreturns a single INTEGER representing the last update time.

        $lastupdate = RRDs::last ...

       [1mRRDs::graph [22mreturns 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);

       [1mRRDs::info [22mreturns 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";
        }

       [1mRRDs::fetch [22mis 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.

[1mNOTE[0m
       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.

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

[1mAUTHOR[0m
       Tobias Oetiker <oetiker@ee.ethz.ch>



1.0.41                            2003-02-19                           RRDs(3)
