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   1  #
   2  # This library is no longer being maintained, and is included for backward
   3  # compatibility with Perl 4 programs which may require it.
   4  #
   5  # In particular, this should not be used as an example of modern Perl
   6  # programming techniques.
   7  #
   8  # Suggested alternative: FileCache
   9  
  10  # Open in their package.
  11  
  12  sub cacheout'open {
  13      open($_[0], $_[1]);
  14  }
  15  
  16  # Close as well
  17  
  18  sub cacheout'close {
  19      close($_[0]);
  20  }
  21  
  22  # But only this sub name is visible to them.
  23  
  24  sub cacheout {
  25      package cacheout;
  26  
  27      ($file) = @_;
  28      if (!$isopen{$file}) {
  29      if (++$numopen > $maxopen) {
  30          local(@lru) = sort {$isopen{$a} <=> $isopen{$b};} keys(%isopen);
  31          splice(@lru, $maxopen / 3);
  32          $numopen -= @lru;
  33          for (@lru) { &close($_); delete $isopen{$_}; }
  34      }
  35      &open($file, ($saw{$file}++ ? '>>' : '>') . $file)
  36          || die "Can't create $file: $!\n";
  37      }
  38      $isopen{$file} = ++$seq;
  39  }
  40  
  41  package cacheout;
  42  
  43  $seq = 0;
  44  $numopen = 0;
  45  
  46  if (open(PARAM,'/usr/include/sys/param.h')) {
  47      local($_, $.);
  48      while (<PARAM>) {
  49      $maxopen = $1 - 4 if /^\s*#\s*define\s+NOFILE\s+(\d+)/;
  50      }
  51      close PARAM;
  52  }
  53  $maxopen = 16 unless $maxopen;
  54  
  55  1;