A little ruby script to show process memory usage grouped by ppid

memgrp

#!/usr/bin/env ruby

def run!

  ps = []
  `ps -el`.split(/\n/).each do |line|
    #   UID   PID  PPID        F CPU PRI NI       SZ    RSS WCHAN     S             ADDR TTY           TIME CMD
    l = line.split("\s")
    x = {
      :uid      => l.shift,
      :pid      => l.shift,
      :ppid     => l.shift,
      :f        => l.shift,
      :cpu      => l.shift,
      :pri      => l.shift,
      :ni       => l.shift,
      :vsz      => l.shift,
      :rss      => l.shift,
      :wchan    => l.shift,
      :s        => l.shift,
      :addr     => l.shift,
      :tty      => l.shift,
      :time     => l.shift,
      :children => []
    }
    x[:cmd] = l.join(" ")
    ps << x
  end
  ps.shift # get rid of headers

  ps.sort!{ |x,y| x[:pid] <=> y[:pid] }.reverse!

  ps.each do |x|
    next if x[:ppid] == "1" || x[:ppid] == "0"
    ps.each do |y|
      if y[:pid] == x[:ppid] then
        y[:children] << x
      end
    end
  end

  ps.delete_if { |x| x[:ppid] != "1" && x[:ppid] != "0" }
  ps.reverse!

  # dispaly results
  ret = []
  ps.each do |x|
    ret << {
      rss:      rss(x),
      cmd:      x[:cmd],
      children: x[:children]
    }
  end

  ret.sort!{ |x,y| y[:rss] <=> x[:rss] }

  puts "RSS\t\tCHILDREN\tCMD"
  ret.each do |x|
    puts "#{x[:rss]}\t\t#{x[:children].size}\t\t#{x[:cmd]}"
  end

end

def rss(x)
  sum = x[:rss].to_i
  x[:children].each{ |y| sum += rss(y) }
  sum
end

run!