I recommend using lexical filehandles: 
open my $rm3d_fh, '>', $fullFileName or die "...$!";
rm3dHeader( $rm3d_fh );

sub rm3dHeader {
    my $fh = shift;

    print $fh "START...";
}

[download]
I think that's easier to understand than trying to pass a glob.

In reply to Re: passing a file handle to a subroutine by rhesa
in thread passing a file handle to a subroutine by kevind0718

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