1  echo "the magic word is xyzzy'
    2  echo "the magic word is xyzzy"
    3  echo "the magic word is xyzzy" | grep the
    4  echo "the magic word is xyzzy" | grep 'm.*d'
    5  echo "the magic word is xyzzy" | grep x
    6  echo "the magic word is xyzzy" | grep y
    7  echo "the magic word is xyzzy" | grep 'y$'
    8  cat names 
    9  grep 'M' names 
   10  grep '^M'
   11  grep '^M' names 
   12  grep 'e$'
   13  grep 'e$' names 
   14  cat names 
   15  grep '^M.*e$' names 
   16  grep 'a|e' names 
   17  grep 'a\|e' names 
   18  egrep 'a\|e' names 
   19  egrep 'a|e' names 
   20  grep 'a|e' names 
   21  grep -E 'a|e' names 
   22  grep [xyz] names 
   23  grep [ae] names 
   24  grep [aiou] names 
   25  grep [^e] names 
   26  grep [^ei] names 
   27  grep '.$' names
   28  grep '.*$' names
   29  ls /usr/share/dict/words 
   30  more /usr/share/dict/words 
   31  wc /usr/share/dict/words 
   32  ls -l
   33  ln -s /usr/share/dict/words 
   34  ls -l
   35  wc words 
   36  grep 'tweet' words 
   37  grep 'twig' words
   38  grep 'qu.*ing' words 
   39  grep 'qu.*ing' words |wc
   40  grep 'qu...ing' words
   41  grep '^qu...ing$' words
   42  grep '^qu....ing$' words
   43  grep '^qu.....ing$' words
   44  grep '^qu......ing$' words
   45  grep '^qu.......ing$' words
   46  grep '^qu........ing$' words
   47  grep 'q[^u]' words 
   48  grep '\(...\).*\1' words
   49  grep '\(.\)\(.\)\(.\)\1\2\3' words 
   50  grep '\(.\)\(.\)\(.\).*\3\2\1' words 
   51  grep '^\(.\)\(.\)\(.\)\3\2\1$' words 
   52  grep '^\(.\)\(.\)\(.\)\(.\)\4\3\2\1$' words 
   53  grep '\(.\)\(.\)\(.\)\(.\)\4\3\2\1' words 
   54  alias
   55  history > lec6.history