You could generate a program.

push @ops, "rename(".text_to_perl_lit($file_from).", ".text_to_perl_li
+t($file_from).");";
...

my $program = join '' map "$_\n", @ops;
if ($preview) {
   print($program);
} else {
   eval $program;
}
[download]

Add error checking to liking. But that might make the preview unreadable. An alternative would be to provide your own operations.

sub xrename {
   if ($preview) {
      print(...);
   } else {
      rename(...);
   }
}

xrename(...);
[download]