Well, you would have to define "work OK" for anybody to answer that question. In this case, I think the answer is "No," because $flat_to_check is not defined, remame is not a function, and if it's a typo for rename, I don't believe you can set a file name to a zero-length string on any O/S. Also, you probably won't be able rename or delete it while it's open.

So:

• Define $flat_to_check.
• You should always check to see if you could open a file. Incidently, the < is superfluous.
• You probably want unlink vs rename.
• You probably can't delete or rename a file while it's open, so you'll have to explicitly close it before trying to delete it. If I remember, Perl does not automatically close files unless an open is executed with the same filehandle.

grammar correction