#
sub cacheout'open
    {
    open($_[0], $_[1]);
    }

# Close as well

sub cacheout'close
    {
    close($_[0]);
    }

# But only this sub name is visible to them.

sub cacheout
    {
    package cacheout;

    ($file) = @_;

    if (!$isopen { $file})
        {
        if (++$numopen > $maxopen)
            {
            local(@lru) = sort
                {
                $isopen { $a} <=> $isopen { $b};
                } keys(%isopen);

            splice(@lru, $maxopen / 3);
            $numopen -= @lru;

            for (@lru)
                {
                &close($_);
                delete $isopen { $_};
                }
            }

        &open($file, ($saw { $file} ++ ? '>>' : '>') . $file) || die "Can't create $file: $!\n";
        }

    $isopen { $file} = ++$seq;
    }

package cacheout;

$seq = 0;
$numopen = 0;

if (open(PARAM, '/usr/include/sys/param.h'))
    {
    local($_, $.);

    while ()
        {
        $maxopen = $1 -4 if /^\s*#\s*define\s+NOFILE\s+(\d+)/;
        }

    close PARAM;
    }

$maxopen = 16 unless $maxopen;

1;