rrdfetchのUNIX時間をローカルタイムに変換する

ruby

(rrdfetch_in_localtime.rb)

#!/usr/bin/env ruby

f = open("|rrdtool fetch #{ARGV[0]} AVERAGE")
f.each do |line|
  if /^(\d+):/ =~ line
    temp = line.split()
    temp[0] = Time.at($1.to_i).strftime("%Y/%m/%d %H:%M:%S")
    puts temp.join(" ")
  end
end
f.close

$ rrdtool fetch localhost_2.rrd AVERAGE
                            ds0                 ds1

1331738100: -nan -nan
1331738400: -nan -nan
...
1331822400: -nan -nan
1331822700: 1.9756373938e+01 4.4640226629e+01
1331823000: 4.9390934844e+00 1.1160056657e+01
1331823300: 4.9390934844e+00 1.1160056657e+01
1331823600: -nan -nan
...
$
$ ./rrdfetch_in_localtime.rb localhost_2.rrd 
2012/03/15 00:15:00 -nan -nan
2012/03/15 00:20:00 -nan -nan
...
2012/03/15 23:40:00 -nan -nan
2012/03/15 23:45:00 1.9756373938e+01 4.4640226629e+01
2012/03/15 23:50:00 4.9390934844e+00 1.1160056657e+01
2012/03/15 23:55:00 4.9390934844e+00 1.1160056657e+01
2012/03/16 00:00:00 -nan -nan
...

awk

$ rrdtool fetch localhost_2.rrd AVERAGE | awk '{print strftime("%Y/%m/%d %H:%M:%S",$1),$2,$3}'

参照したURL:
http://pooh.gr.jp/?p=82
wikipedia:UNIX時間