tail -f | nl

tail -f | grep -n

$ tail -f /var/log/foo.log | less -N

1 Jan 17 22:11:58 greeneggs fprintd[4323]: ** Message: entering main loop
  2 Jan 17 22:12:01 greeneggs su: (to root) saml on pts/5
  3 Jan 17 22:12:28 greeneggs fprintd[4323]: ** Message: No devices in use, exit
  4 Jan 17 22:12:56 greeneggs gnome-session[1876]: 22:12:56 | Git | personal_repo | Checking for remote changes...
  5 Jan 17 22:12:56 greeneggs gnome-session[1876]: 22:12:56 | Cmd | personal_repo | git rev-parse HEAD
  6 Jan 17 22:12:56 greeneggs gnome-session[1876]: 22:12:56 | Cmd | personal_repo | git ls-remote --heads --exit-code "ssh://sam@sparkleshare.jake
  6 8us.org/home/sam/SparkleShare/personal_repo.git" master
  7 Jan 17 22:12:58 greeneggs gnome-session[1876]: X11 forwarding request failed on channel 1
  8 Jan 17 22:12:58 greeneggs gnome-session[1876]: 22:12:58 | Git | personal_repo | No remote changes, local+remote: 532213be48cce3b93cb177d409faa
  8 03b71d0cfa5
  9 Jan 17 22:13:35 greeneggs gnome-session[1876]: 22:13:35 | ListenerTcp | Pinging tcp://notifications.sparkleshare.org:443/
 10 Jan 17 22:13:35 greeneggs gnome-session[1876]: 22:13:35 | ListenerTcp | Received pong from tcp://notifications.sparkleshare.org:443/

less -N +F <filepath>

tail -f -n100000000 filename.log | grep -n ''

tail -f -n100000000 filename.log | grep -n '' | tail -n10