This is what I use:

    # Get filename components
    ($filename, $filedir, $filext) = fileparse($0, '\..*');

    # Create filename; note the ./log sub-dir
    $logfile = "${filedir}log/$filename.log";

    # Redirect STDOUT & STDERR to named logfile
    open( STDOUT, ">>$logfile") or
                        die "\nUnable to open STDOUT -> $logfile: $!\n
+";
    open( STDERR, ">>&STDOUT");

    # Set autoflush on
    select (STDERR); $| = 1;
    select (STDOUT); $| = 1;
[download]

Works fine for me.
The reason I unbuffer the log file is that if the prog exits unexpectedly, you may not get the last msg or 2, which are usually the ones that tell you why/where it failed(!)
Cheers
Chris