use warnings;
use strict;

open outFile, '>', 'test.rsf';
print outFile "ÐÏࡱá                >  þÿ\nThis is plain text";
close outFile;

local @ARGV = ('test.rsf');
local $^I = '.bak';

while (<>)
  {
  chomp;
  print STDOUT (length $_) . " >$_<\n";
  print ">$_<\n";
  }