Yes, I think this is the safest way. close FH if open FH, ">".$filename But overwrite mode might do an unlink/link combo. (meaning that the file $filename might be deleted, then recreated as a empty file). So this could be the same asunlink $filename; open ">$filename"; I am not sure. Anybody actually know if there is a difference? The file inode number should still be the same though for either method.
Depending on what you are doing this is probably good enough.