use Filesys::Df;

for my $filesys ( qw { / /usr /opt /sybase /spooltmp /var  /home
 } ) {
    my $df = df( $filesys );
    next if $df->{used} < 0 or 0 == $df->{user_blocks};
    push @df, [ $filesys, $df->{used} / $df->{user_blocks}, $df->{bavail}*1024 ];
}