index(STR,SUBSTR,POSITION)

     index(STR,SUBSTR)

             Returns the position  of  the  first  occurrence  of
             SUBSTR  in STR at or after POSITION.  If POSITION is
             omitted, starts searching from the beginning of  the
             string.  The return value is based at 0, or whatever
             you've set the $[ variable to.  If the substring  is
             not  found,  returns  one  less than the base, ordi-
             narily -1.