4 use vars qw(@ISA $VERSION);
12 bootstrap RRDs $VERSION;
19 RRDs - Access rrdtool as a shared module
32 RRDs::times(start, end)
36 =head2 Calling Sequence
38 This module accesses rrdtool functionality directly from within perl. The
39 arguments to the functions listed in the SYNOPSIS are explained in the regular
40 rrdtool documentation. The commandline call
42 rrdtool update mydemo.rrd --template in:out N:12:13
46 RRDs::update ("mydemo.rrd", "--template", "in:out", "N:12:13");
54 The RRDs::times function takes two parameters: a "start" and "end" time.
55 These should be specified in the B<AT-STYLE TIME SPECIFICATION> format
56 used by rrdtool. See the B<rrdfetch> documentation for a detailed
57 explanation on how to specify time.
61 The RRD functions will not abort your program even when they can not make
62 sense out of the arguments you fed them.
64 The function RRDs::error should be called to get the error status
65 after each function call. If RRDs::error does not return anything
66 then the previous function has completed its task successfully.
69 RRDs::update ("mydemo.rrd","N:12:13");
71 die "ERROR while updating mydemo.rrd: $ERR\n" if $ERR;
75 The functions RRDs::last, RRDs::graph, RRDs::info, RRDs::fetch and RRDs::times
76 return their findings.
78 B<RRDs::last> returns a single INTEGER representing the last update time.
80 $lastupdate = RRDs::last ...
82 B<RRDs::graph> returns an pointer to an ARRAY containing the x-size and y-size of the
83 created image and results of the PRINT arguments.
85 ($averages,$xsize,$ysize) = RRDs::graph ...
86 print "Imagesize: ${xsize}x${ysize}\n";
87 print "Averages: ", (join ", ", @$averages);
89 B<RRDs::info> returns a pointer to a hash. The keys of the hash
90 represent the property names of the rrd and the values of the hash are
91 the values of the properties.
93 $hash = RRDs::info "example.rrd";
94 foreach my $key (keys %$hash){
95 print "$key = $$hash{$key}\n";
98 B<RRDs::updatev> also returns a pointer to hash. The keys of the hash
99 are concatenated strings of a timestamp, RRA index, and data source name for
100 each consolidated data point (CDP) written to disk as a result of the
101 current update call. The hash values are CDP values.
103 B<RRDs::fetch> is the most complex of
104 the pack regarding return values. There are 4 values. Two normal
105 integers, a pointer to an array and a pointer to a array of pointers.
107 my ($start,$step,$names,$data) = RRDs::fetch ...
108 print "Start: ", scalar localtime($start), " ($start)\n";
109 print "Step size: $step seconds\n";
110 print "DS names: ", join (", ", @$names)."\n";
111 print "Data points: ", $#$data + 1, "\n";
113 foreach my $line (@$data) {
114 print " ", scalar localtime($start), " ($start) ";
116 foreach my $val (@$line) {
117 printf "%12.1f ", $val;
122 B<RRDs::times> returns two integers which are the number of seconds since
123 epoch (1970-01-01) for the supplied "start" and "end" arguments, respectively.
125 See the examples directory for more ways to use this extension.
129 If you are manipulating the TZ variable you should also call the posixs
130 function tzset to initialize all internal state of the library for properly
131 operating in the timezone of your choice.
140 Tobias Oetiker E<lt>oetiker@ee.ethz.chE<gt>