memcached-key-dump.rb

require 'socket'

MEMCACHED_PORT = 11211

ip = ARGV[0]
sock = TCPSocket.open(ip, MEMCACHED_PORT)

def send_command(command, sock)
  sock.puts command
  sock.flush

  lines = []
  line = ""
  while line != "END"
    line = sock.gets.chomp
    lines << line
  end
  lines
end

res = send_command("stats slabs", sock)
slab_ids = res.map do |line|
  m = line.match(/STAT (.*):.*/)
  if m
    m[1]
  else
    nil
  end
end.select{|id| id}.uniq

memcached_keys = slab_ids.map do |id|
  res = send_command("stats cachedump #{id} 0", sock)
  res.map do |line|
    m = line.match(/ITEM (.*) \[.*/)
    if m
      m[1]
    else
      nil
    end
  end.select{|id| id}
end.flatten

puts memcached_keys

sock.close