Ruby sort ps

From EggeWiki

Today I needed to sort ps by the total CPU time. I also wanted to sum all the same type processes together. Here's the script I came up with

#!/bin/env ruby
# 
# Given the output from 'ps -o user,time,nlwp,fname' this script will sum the CPU time
#
 
header = nil
procs = {}
procs.default = 0
while((line = STDIN.gets)) 
  f = line.chomp.split(' ') 
  if !header then 
    header = f 
    TIME = f.rindex('TIME')
    CMD = f.rindex('CMD') || f.rindex('COMMAND')
  else 
    time = f[TIME].split(':')
    seconds = time[0].to_i * 60 + time[1].to_i
    cmd = f[CMD]
    procs[cmd] += seconds
  end 
end 
 
sum = 0.0
procs.each { |k,v| sum += v }
sorted = procs.sort { |a,b| b[1]<=>a[1] }
sorted.each do |k|
  puts sprintf("%-10s %5.2f%%", k[0], (k[1] / sum) * 100.0)
end

Here's a sample of it's usage:

$ ps -A -o user,time,nlwp,fname | ./sumcputime.rb | head
java       27.19%
dataserv   20.10%
Xvnc        7.21%
view_ser    4.06%
backupse    3.86%
httpd       3.64%
nscd        2.81%
omniName    2.38%
se.sparc    2.34%
compute_    2.10%