# Spell pipeline - Linux version of Bentley "pearl" CACM 28(5) May 1985 p. 457
tr '[A-Z]' '[a-z]' |         # map upper to lower case
 tr -c '[a-z]' '\n' |        # change punctuation and spaces to linebreaks
   sort |                    # put words in alphabetic order
     uniq |                  # remove duplicate lines (or use sort -u above)
       comm - -23 /usr/dict/words # report words not in dictionary