use Benchmark qw(cmpthese);
cmpthese(50,
	 {
	  while=>sub{
	    open(SITE, "/usr/share/dict/words");
	    my $xml;
	    while (<SITE>) {
	      $xml .= $_;
	    }
	    close(SITE);
	  }
	  ,
	  slurp=>sub{
	    open(SITE, "/usr/share/dict/words");
	    my $xml;
	    local($/);
	    undef $/;
	    $xml = <SITE>;
	    close(SITE);
	  }
	  ,
	  join=>sub{
	    open(SITE, "/usr/share/dict/words");
	    my $xml = join('', <SITE>);
	    close(SITE);
	  }
	  ,
	  sys=>sub{
	    sysopen(SITE, "/usr/share/dict/words", O_RDONLY);
	    sysread SITE, my $xml, -s SITE;
	    close(SITE);
	    }
	  }
);
__END__
Benchmark: timing 50 iterations of join, slurp, sys, while...
      join:  8 wallclock secs ( 7.99 usr +  0.17 sys =  8.16 CPU) @  6.13/s (n=50)
     slurp:  0 wallclock secs ( 0.12 usr +  0.14 sys =  0.26 CPU) @ 192.31/s (n=50)
            (warning: too few iterations for a reliable count)
       sys:  1 wallclock secs ( 0.01 usr +  0.25 sys =  0.26 CPU) @ 192.31/s (n=50)
            (warning: too few iterations for a reliable count)
     while:  5 wallclock secs ( 5.09 usr +  0.12 sys =  5.21 CPU) @  9.60/s (n=50)
        Rate  join while   sys slurp
join  6.13/s    --  -36%  -97%  -97%
while 9.60/s   57%    --  -95%  -95%
sys    192/s 3038% 1904%    --   -0%
slurp  192/s 3038% 1904%    0%    --