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Posted by John W. Krahn on March 13, 2008, 5:53 pm
Please log in for more thread options John W. Krahn wrote:
> ShaunJ wrote:
>> The following snippet leaks memory until it breaks and falls down when
>> m// is used on a very long line. It works fine if the line lengths are
>> short. Try
>> ./test.pl /usr/share/dict/words /usr/share/dict/words
>> Depending on your dictionary, you'll see that compiling the regex
>> takes about 200 MB. However the following matching loop leaks memory
>> at an alarming rate. Start up `top` and watch it run. I'm using Perl
>> 5.8.6 built for darwin-thread-multi-2level. If anyone cares to confirm
>> or deny this behaviour for other architectures or version of Perl,
>> that would be interesting too.
>>
>> Cheers,
>> Shaun
>>
>> #!/usr/bin/perl
>> use strict;
>> use English;
>> open REFILE, '<' . shift;
>> chomp (my @restrings = <REFILE>);
>> close REFILE;
>> my @re = map { qr/$_/ } @restrings;
>>
>> open TEXTFILE, '<' . shift;
>> chomp (my @text = <TEXTFILE>);
>> close TEXTFILE;
>> my $text = join '', @text;
>>
>> foreach my $re (@re) {
>> if ($text =~ m/$re/) {
>> print $LAST_MATCH_START[0], "\n";
>> }
>> }
>
> I tested it and if I remove the English module it works fine.
> (So don't use English.pm!)
Or at least don't use the $PREMATCH, $MATCH, or $POSTMATCH variables:
use English qw( -no_match_vars );
John
--
Perl isn't a toolbox, but a small machine shop where you
can special-order certain sorts of tools at low cost and
in short order. -- Larry Wall
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