Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!zaphod.mps.ohio-state.edu!swrinde!ucsd!ucbvax!iwarp.intel.com!news
From: merlyn@iwarp.intel.com (Randal Schwartz)
Newsgroups: comp.lang.perl
Subject: Re: Why is this so slow?
Message-ID: <1990Dec6.205447.13500@iwarp.intel.com>
Date: 6 Dec 90 20:54:47 GMT
References: <1990Dec6.194412.9132@cunixf.cc.columbia.edu>
Sender: news@iwarp.intel.com
Reply-To: merlyn@iwarp.intel.com (Randal Schwartz)
Organization: Stonehenge; netaccess via Intel, Beaverton, Oregon, USA
Lines: 63
In-Reply-To: ben@cunixf.cc.columbia.edu (Ben Fried)

In article <1990Dec6.194412.9132@cunixf.cc.columbia.edu>, ben@cunixf (Ben Fried) writes:
| mainloop:
| while(read(STDIN, $_, 2048)) {
|     foreach $i ($[..length($_)) {
| 	$num_to_print = $i;
| 	$oc=$c;
| 	$c = substr($_, $i, 1);
| 	if ($tektronixmode) {
| 	    if (($c eq "\f") && ($oc eq "\033")) {
| 		$pageno++;
| 	    }
| 	} else {
| 	    if ($ascii_mode) {
| 		if ($c eq "\n") {
| 		    $lineno++;
| 		    if ($lineno == $lines_per_page) {
| 			$lineno = 0;
| 			$pageno++;
| 		    }
| 		}
| 	    } else {
| 		if ($c eq "\f") {
| 		    $lineno = 0;
| 		    $pageno++;
| 		}
| 	    }
| 	}
| 
| 	if ($pageno >= $max_pages) {
| 	    $debug && print STDERR "aborted at page $pageno\n";
| 	    print STDOUT substr($_, $[, $num_to_print);
| 	    last mainloop;
| 	}
| 
|     }
| 
|     print STDOUT;
| }

Hmm.  That's probably the right way to do it in some other language
besides Perl.  (It smells vaguely BASIC-like, or maybe C-like.)

Anyway, as a first cut, I'd do something like:

$lines_per_page = 66; $max_pages = 100; # you forgot this
while (<>) {
	$lineno++;
	$pageno++, $lineno = 0 if /\f/ || ($lineno >= $lines_per_page);
	die "Aborted at page $pageno\n" if $pageno >= $max_pages;
	print;
}

Yes?  Maybe?  OK, so I didn't add the tek vs. ascii mode, but that'd
only make it one line longer. :-)

I think you'll find this runs a teensy-tiny bit faster. :-)

print "Just another Perl hacker,"
-- 
/=Randal L. Schwartz, Stonehenge Consulting Services (503)777-0095 ==========\
| on contract to Intel's iWarp project, Beaverton, Oregon, USA, Sol III      |
| merlyn@iwarp.intel.com ...!any-MX-mailer-like-uunet!iwarp.intel.com!merlyn |
\=Cute Quote: "Intel: putting the 'backward' in 'backward compatible'..."====/


Brought to you by Super Global Mega Corp .com