chomp($line = < IN >);
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<> represents two different operators, readline or glob.    When you have whitespace it becomes the glob operator so you have:

    chomp($line = glob 'IN' );
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Or simply:

    chomp($line = 'IN' );
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    for ($i=0; $i<@xyzvals; $i++) {
        $s{$bb}{$xyz[$i]} = $xyzvals[$i];
        }
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In perl that is usually written as:

    for my $i ( 0 .. $#xyzvals ) {
        $s{ $bb }{ $xyz[ $i ] } = $xyzvals[ $i ];
        }
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Or you could do the same thing with a hash slice:

    @{ $s{ $bb } }{ @xyz[ 0 .. $#xyzvals ] } = @xyzvals;
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