Here is a Factor version:

  : print-ing ( filepath encoding -- )
  [ [ 
      " " split
      [ dup "ing" tail? [ print ] [ drop ] if ] each ] 
    each-line ]
  with-file-reader ;

It's kind of ugly because it's designed to print out the values without leaving anything on the stack. It can be prettier if it produces an array of matching words

  : collect-ing ( filepath encoding -- seq ) { } -rot 
  [ [
      " " split 
      [ "ing" tail? ] filter append ] 
    each-line ] 
  with-file-reader ;

and then just prints that out

  : print-ing ( filepath encoding -- )
  collect-ing [ print ] each ;