4 use vars qw(@ISA $VERSION);
12 bootstrap RRDs $VERSION;
19 RRDs - Access RRDtool as a shared module
33 RRDs::times(start, end)
37 =head2 Calling Sequence
39 This module accesses RRDtool functionality directly from within perl. The
40 arguments to the functions listed in the SYNOPSIS are explained in the regular
41 RRDtool documentation. The commandline call
43 rrdtool update mydemo.rrd --template in:out N:12:13
47 RRDs::update ("mydemo.rrd", "--template", "in:out", "N:12:13");
55 The RRDs::times function takes two parameters: a "start" and "end" time.
56 These should be specified in the B<AT-STYLE TIME SPECIFICATION> format
57 used by RRDtool. See the B<rrdfetch> documentation for a detailed
58 explanation on how to specify time.
62 The RRD functions will not abort your program even when they can not make
63 sense out of the arguments you fed them.
65 The function RRDs::error should be called to get the error status
66 after each function call. If RRDs::error does not return anything
67 then the previous function has completed its task successfully.
70 RRDs::update ("mydemo.rrd","N:12:13");
72 die "ERROR while updating mydemo.rrd: $ERR\n" if $ERR;
76 The functions RRDs::last, RRDs::graph, RRDs::info, RRDs::fetch and RRDs::times
77 return their findings.
79 B<RRDs::last> returns a single INTEGER representing the last update time.
81 $lastupdate = RRDs::last ...
83 B<RRDs::graph> returns an pointer to an ARRAY containing the x-size and y-size of the
84 created image and results of the PRINT arguments.
86 ($averages,$xsize,$ysize) = RRDs::graph ...
87 print "Imagesize: ${xsize}x${ysize}\n";
88 print "Averages: ", (join ", ", @$averages);
90 B<RRDs::info> returns a pointer to a hash. The keys of the hash
91 represent the property names of the RRD and the values of the hash are
92 the values of the properties.
94 $hash = RRDs::info "example.rrd";
95 foreach my $key (keys %$hash){
96 print "$key = $$hash{$key}\n";
99 B<RRDs::updatev> also returns a pointer to hash. The keys of the hash
100 are concatenated strings of a timestamp, RRA index, and data source name for
101 each consolidated data point (CDP) written to disk as a result of the
102 current update call. The hash values are CDP values.
104 B<RRDs::fetch> is the most complex of
105 the pack regarding return values. There are 4 values. Two normal
106 integers, a pointer to an array and a pointer to a array of pointers.
108 my ($start,$step,$names,$data) = RRDs::fetch ...
109 print "Start: ", scalar localtime($start), " ($start)\n";
110 print "Step size: $step seconds\n";
111 print "DS names: ", join (", ", @$names)."\n";
112 print "Data points: ", $#$data + 1, "\n";
114 foreach my $line (@$data) {
115 print " ", scalar localtime($start), " ($start) ";
117 foreach my $val (@$line) {
118 printf "%12.1f ", $val;
123 B<RRDs::times> returns two integers which are the number of seconds since
124 epoch (1970-01-01) for the supplied "start" and "end" arguments, respectively.
126 See the examples directory for more ways to use this extension.
130 If you are manipulating the TZ variable you should also call the posixs
131 function tzset to initialize all internal state of the library for properly
132 operating in the timezone of your choice.
141 Tobias Oetiker E<lt>oetiker@ee.ethz.chE<gt>