1: #!/bin/ksh
   2: 
   3: # If we have not redirected standard output, save a copy of
   4: # the output of this script into a file, but still send a
   5: # copy to the screen.
   6: 
   7: if [[ -t 1 ]] ; then
   8:   # Only do this if fd 1 (stdout) is still connected
   9:   # to a terminal
  10: 
  11:   # We want the standard output of the "tee" process
  12:   # to go explicitly to the screen (/dev/tty)
  13:   # and the second copy goes into a logfile named $0.out
  14: 
  15:   tee $0.out >/dev/tty |&
  16: 
  17:   # Our stdout all goes into this coprocess
  18:   exec 1>&p
  19: fi
  20: 
  21: # Now generate some output
  22: print "User activity snapshot on $(hostname) at $(date)"
  23: print
  24: who