386BSD 0.1 development

[unix-history] / usr / othersrc / public / perl-4.019 / lib / cacheout.pl

#!/usr/bin/perl

# Open in their package.

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

# 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 (<PARAM>) {
       $maxopen = $1 - 4 if /^\s*#\s*define\s+NOFILE\s+(\d+)/;
   }
   close PARAM;
}
$maxopen = 16 unless $maxopen;

1;