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