501  cd humboldt/f12cs279/279labs/279lab07
  502  ls
  503  grep [0-9]
  504  grep ^[0-9]$
  505  grep ^[[:blank:]]*[0-9][[:blank:]]*$
  506  grep g\([a-z]*\)moo\1
  507  grep "g\([a-z]*\)moo\1"
  508  grep "g\([a-z]*\)moo\([A-Z][0-9]\)\1\2"
  509  grep "^\([A-Z]\)\1*$"
  510  grep "^[0-9]\{5\}$"
  511  grep "^[0-9]\{5,\}$"
  512  grep "^[0-9]\{5,7\}$"
  513  grep "^[0-9]\{0,3\}$"
  514  egrep a+
  515  egrep ^a?$
  516  egrep "(cat|dog)"
  517  egrep "(cat|dog)(fish|fight)"
  518  emacs cmd-line-args.sh
  519  cmd-line-args.sh 1 2 3
  520  more play-args.sh
  521  play-args.sh the "rain in" 'Spain stays'