As holli said, there is nothing wrong within the lines you posted. Ist this a command line app or do you try to do this from within CGI or mod_perl program?

Try a small modification on your code:

  open HELLO, ">file.txt" or die "$!";
  select HELLO or die "$!";
  print "hi !";
[download]

and respond to this thread with the error message shown.

Regards

mwa