term% ls -F
term% pwd
term% cat index.txt
PTX(1)                      General Commands Manual                     PTX(1)

       ptx - permuted index

       ptx [ option ] ...  [ input [ output ] ]

       Ptx  generates  a permuted index to file input on file output (standard
       input and output default).  It has three phases:  the  first  does  the
       permutation,  generating  one  line  for each keyword in an input line.
       The keyword is rotated to the front.  The permuted file is then sorted.
       Finally,  the sorted lines are rotated so the keyword comes at the mid‐
       dle of the page.  Ptx produces output in the form:

              .xx "tail" "before keyword" "keyword and after" "head"

       where .xx may be an nroff or troff(1) macro  for  user-defined  format‐
       ting.   The  before keyword and keyword and after fields incorporate as
       much of the line as will fit around the keyword when it is  printed  at
       the  middle  of  the  page.  Tail and head, at least one of which is an
       empty string "", are wrapped-around pieces small enough to fit  in  the
       unused  space at the opposite end of the line.  When original text must
       be discarded, `/' marks the spot.

       The following options can be applied:

       -f     Fold upper and lower case letters for sorting.

       -t     Prepare the output for the  phototypesetter;  the  default  line
              length is 100 characters.

       -w n   Use  the next argument, n, as the width of the output line.  The
              default line length is 72 characters.

       -g n   Use the next argument, n, as the number of characters  to  allow
              for  each  gap  among  the  four  parts  of  the line as finally
              printed.  The default gap is 3 characters.

       -o only
              Use as keywords only the words given in the only file.

       -i ignore
              Do not use as keywords any words given in the ignore  file.   If
              the  -i and -o options are missing, use /usr/lib/eign as the ig‐
              nore file.

       -b break
              Use the characters in the break file to separate words.  In  any
              case,  tab,  newline,  and  space  characters are always used as
              break characters.

       -r     Take any leading nonblank characters of each input line to be  a
              reference identifier (as to a page or chapter) separate from the
              text of the line.  Attach that identifier as a 5th field on each
              output line.

       The index for this manual was generated using ptx.


       Line  length  counts  do  not  account for overstriking or proportional