lsof

list open files

• Updated, better example

  lsof -i TCP

• Older example

  # lsof | grep TCP
  portmap    2587   rpc    4u     IPv4       5544                 TCP *:sunrpc (LISTEN)
  rpc.statd  2606  root    6u     IPv4       5585                 TCP *:668 (LISTEN)
  sshd       2788  root    3u     IPv6       5991                 TCP *:ssh (LISTEN)
  sendmail   2843  root    4u     IPv4       6160                 TCP badhd:smtp (LISTEN)
  vsftpd     9337  root    3u     IPv4      34949                 TCP *:ftp (LISTEN)
  cupsd     16459  root    0u     IPv4      41061                 TCP badhd:ipp (LISTEN)
  sshd      16892  root    3u     IPv6      61003                 TCP badhd.mshome.net:ssh->kontiki.mshome.net:4661 (ESTABLISHED)

lsof -c QuickTime

• you can replace sort | uniq with “sort -u”

lsof | grep ' root ' | awk '{print $NF}' | sort | uniq | wc -l
179