doc/rrdruby.pod

   1 =head1 NAME
   2
   3 rrdruby - About the RRD Ruby bindings
   4
   5 =head1 SYNOPSIS
   6
   7  require "RRD"
   8  RRD.create(
   9     rrd,
  10     "--step", "300",
  11     "DS:a:GAUGE:600:U:U",
  12     "DS:b:GAUGE:600:U:U",
  13     "RRA:AVERAGE:0.5:1:300")
  14
  15 =head1 DESCRIPTION
  16
  17 The B<rrdtool> functions are directly callable via the Ruby programming
  18 language. This wrapper implementation has been written from the scratch
  19 (without  SWIG)
  20
  21 The API's simply expects string parameters to the functions.  Please refer
  22 to the other B<rrdtool> documentation for functions and valid arguments.
  23
  24 =head1 EXAMPLE
  25
  26  $: << '/path/to/rrdtool/lib/ruby/1.8/i386-linux'
  27  require "RRD"
  28
  29  name = "test"
  30  rrd = "#{name}.rrd"
  31  start = Time.now.to_i
  32
  33  RRD.create(
  34     rrd,
  35     "--start", "#{start - 1}",
  36     "--step", "300",
  37         "DS:a:GAUGE:600:U:U",
  38     "DS:b:GAUGE:600:U:U",
  39     "RRA:AVERAGE:0.5:1:300")
  40  puts
  41
  42  puts "updating #{rrd}"
  43  start.to_i.step(start.to_i + 300 * 300, 300) { |i|
  44     RRD.update(rrd, "#{i}:#{rand(100)}:#{Math.sin(i / 800) * 50 + 50}")
  45  }
  46  puts
  47
  48  puts "fetching data from #{rrd}"
  49  (fstart, fend, data, step) = RRD.fetch(rrd, "--start", start.to_s, "--end",
  50       (start + 300 * 300).to_s, "AVERAGE")
  51  puts "got #{data.length} data points from #{fstart} to #{fend}"
  52  puts
  53
  54  puts "generating graph #{name}.png"
  55  RRD.graph(
  56    "#{name}.png",
  57     "--title", " RubyRRD Demo",
  58     "--start", "#{start+3600}",
  59     "--end", "start + 1000 min",
  60     "--interlace",
  61     "--imgformat", "PNG",
  62     "--width=450",
  63     "DEF:a=#{rrd}:a:AVERAGE",
  64     "DEF:b=#{rrd}:b:AVERAGE",
  65     "CDEF:line=TIME,2400,%,300,LT,a,UNKN,IF",
  66     "AREA:b#00b6e4:beta",
  67     "AREA:line#0022e9:alpha",
  68     "LINE3:line#ff0000")
  69  puts
  70
  71 If you use the B<--ruby-site-install> configure option you can drop the $:
  72 line since the RRDtool module will be found automatically.
  73
  74 If RRDtool runs into trouble, it will throw an exception which you might
  75 want to catch.
  76
  77 =head1 SEE ALSO
  78
  79 rrdcreate, rrdupdate, rrdgraph, rrddump, rrdfetch, rrdtune, rrdlast,
  80 rrdxport, rrdinfo
  81
  82 =head1 AUTHOR
  83
  84 Loïs Lherbier E<lt>lois.lherbier@covadis.chE<gt>
  85
  86 Miles Egan E<lt>miles@caddr.comE<gt>