Simple vmstat command with vmstat gem (gem install vmstat)

ruby-vmstat.rb

#!/usr/bin/env ruby
# 
# Simple vmstat command with vmstat gem
# ex)
# $ ./ruby-vmstat.rb 1 3
# cpu0  cpu1	cpu2	cpu3	memory	load average 	
# i	i	i	i	free		1m	5m	15m	
# 88.4	96.8	89.0	96.9	1093		0.5	0.9	0.9	2013-01-24 09:09:09 -0800
# 88.4	96.8	89.0	96.9	1093		0.5	0.9	0.9	2013-01-24 09:09:10 -0800
# 88.4	96.8	89.0	96.9	1093		0.5	0.9	0.9	2013-01-24 09:09:11 -0800

require 'vmstat'

def to_per(num)
  sprintf("%.1f", num*100)
end

def to_ldavg(avg)
  sprintf("%.1f", avg)
end

def print_cpu_info(cpus, header=0)
  case header
  when 1
    1.upto(cpus.size) do |num|
      #print "cpu#{num-1}\t\t\t\t\t"
      print "cpu#{num-1}\t"
    end
    return
  when 2
    1.upto(cpus.size) do |num|
      #print "n\tu\ts\tni\ti\t"
      print "i\t"
    end
    return
  end
  cpus.each do |c|
    total = c.user + c.system + c.idle
    list = []
    #list << c.num
    #list << [c.user, c.system, c.idle].map{|v| to_per(v.to_f/total)}
    list << [c.idle].map{|v| to_per(v.to_f/total)}
    #list << c.nice
    print list.join("\t") + "\t"
  end
end

def print_memory_info(mem, header=0)
  case header
  when 1
    print "memory\t"
    return
  when 2
    print "free\t"
    return
  end
  print "#{mem.free/1024}\t"
end

def print_load_avg_info(ldavg, header=0)
  case header
  when 1
    print "load average \t"
    return
  when 2
    print "1m\t5m\t15m\t"
    return
  end
  print "#{to_ldavg ldavg.one_minute}\t#{to_ldavg ldavg.five_minutes}\t#{to_ldavg ldavg.fifteen_minutes}\t"
end

def print_time
  print Time.now
end

def dump_all_info(header=false)
  cpus = Vmstat.cpu
  memory = Vmstat.memory
  load_avg = Vmstat.load_average 
  net_ifs = Vmstat.network_interfaces

  if header
    print_cpu_info(cpus, 1)
    print_memory_info(memory, 1)
    print_load_avg_info(load_avg, 1)
    puts
    print_cpu_info(cpus, 2)
    print_memory_info(memory, 2)
    print_load_avg_info(load_avg, 2)
    puts
    return
  end
  print_cpu_info(cpus)
  print_memory_info(memory)
  print_load_avg_info(load_avg)
  print_time
  puts
end

def dump_loop(sleep_sec, loop_num)
  i=0
  while true
    dump_all_info
    i += 1
    break unless i < loop_num or loop_num == 0
    sleep sleep_sec
  end
end

dump_all_info true

sleep_sec = ARGV[0] ? ARGV[0].to_i : 0
loop_num = ARGV[1] ? ARGV[1].to_i : 0
loop_num = 1 if sleep_sec == 0
dump_loop(sleep_sec, loop_num)