Perl300 has asked for the wisdom of the Perl Monks concerning the following question:

Hello monks,

Please forgive me for asking something that might be very simple. I have a string variable $form_dump that is bascially the output of $query->Dump; from a html form submit. So everything in the form is taken into this string variable, which is a multiline variable. The contents of it look like:

<ul>
<li><strong>site_user</strong></li>
<ul>
<li>user1</li>
</ul>
<li><strong>compare_hidden</strong></li>
<ul>
<li>average_speed_answer  25 60 30 60 ^M<br />
 calls_waiting  300 500 300 500 ^M<br />
 many more rows here
 post_ivr_calls_handled Wisconsin 50 100 50 100 ^M<br />
 post_ivr_calls_handled Wyoming 50 100 50 100 ^M<br />
</li>
<li><strong>calls_waiting_good_high</strong></li>
<ul>
<li>300</li>
</ul>
<li><strong>calls_waiting_warning_low</strong></li>
<ul>

[download]

What I am trying to do is to get each line between fourth pair of <li> & </li> and put those lines in an array. So far I have tried:

if ( $form_dump =~ m{(<li>)(.*?)(</li>)}s ) {
    my $inside_li = $2;
    print $fh "Value of \$inside_li: $inside_li \n";
}

[download]

This gives the text between first pair of <li> & </li> which is <strong>site_user</strong>.

Can I get some clues on how to skip the first three pairs of <li> & </li> and and then stop after text between fourth pair is pulled. I had tried something like $form_dump =~ m{(<li>)(^average_.*?)(</li>)}s in an attempt to get only that text which starts with "average_" but it doesn't match anything and $inside_li prints blank.

I am doing something wrong or missing something there.

Update: Updated subject line to mark solved.

Replies are listed 'Best First'.
Re: Query about regular expression (HTML Parser)
by jeffa (Bishop) on Sep 23, 2015 at 23:49 UTC

    I would use a parser for that instead. Here's some code to get you started should you choose this path: 

    use strict;
use warnings;
use Data::Dumper;
use HTML::TokeParser::Simple;

my $p = HTML::TokeParser::Simple->new( *DATA );
my $count = 0;
my @array;
while ( my $token = $p->get_token ) {
    next unless $token->is_start_tag('li');
    next unless ++$count > 3;

    while ( $token = $p->get_token ) {
        last if $token->is_end_tag('li');
        my $text = $token->as_is;
        $text =~ s/^\s*//;
        $text =~ s/\s*$//;
        push @array, $text unless $token->is_tag('br');
    }
    last;
}

print Dumper \@array;


__DATA__
<ul>
<li><strong>site_user</strong></li>
<ul>
<li>user1</li>
</ul>
<li><strong>compare_hidden</strong></li>
<ul>
<li>average_speed_answer  25 60 30 60 ^M<br />
 calls_waiting  300 500 300 500 ^M<br />
 many more rows here
 post_ivr_calls_handled Wisconsin 50 100 50 100 ^M<br />
 post_ivr_calls_handled Wyoming 50 100 50 100 ^M<br />
</li>
<li><strong>calls_waiting_good_high</strong></li>
<ul>
<li>300</li>
</ul>
<li><strong>calls_waiting_warning_low</strong></li>
<ul>

    [download]

    jeffa

    L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)
[reply]
[d/l]
      Too much work :) HTML::TreeBuilder::XPath is less work 
      #!/usr/bin/perl --
use strict;
use warnings;
use HTML::TreeBuilder::XPath;
my $tree = HTML::TreeBuilder::XPath->new;
$tree->ignore_unknown(0);;
$tree->implicit_tags(0);
$tree->no_expand_entities(1);
$tree->ignore_unknown(0);
$tree->ignore_ignorable_whitespace(0);
$tree->no_space_compacting(1);
$tree->store_comments(1);
$tree->store_pis(1);

$tree->parse(q{
<ul>
<li><strong>site_user</strong></li>
<ul>
<li>user1</li>
</ul>
<li><strong>compare_hidden</strong></li>
<ul>
<li>average_speed_answer  25 60 30 60 ^M<br />
 calls_waiting  300 500 300 500 ^M<br />
 many more rows here
 post_ivr_calls_handled Wisconsin 50 100 50 100 ^M<br />
 post_ivr_calls_handled Wyoming 50 100 50 100 ^M<br />
</li>
<li><strong>calls_waiting_good_high</strong></li>
<ul>
<li>300</li>
</ul>
<li><strong>calls_waiting_warning_low</strong></li>
<ul>});
$tree->eof;

my @li = $tree->findnodes( q{    //li[ contains( ., 'average' ) ]   } 
+) ;
for my $ll ( @li ){
    $ll->dump;
    print $ll->as_text, "\n";;
}

__END__
<li> @0.1.7.1
  "average_speed_answer  25 60 30 60 ^M"
  <br /> @0.1.7.1.1
  "\x0a calls_waiting  300 500 300 500 ^M"
  <br /> @0.1.7.1.3
  "\x0a many more rows here\x0a post_ivr_calls_handled Wisconsin 50 10
+0 50..."
  <br /> @0.1.7.1.5
  "\x0a post_ivr_calls_handled Wyoming 50 100 50 100 ^M"
  <br /> @0.1.7.1.7
  "\x0a"
average_speed_answer  25 60 30 60 ^M
 calls_waiting  300 500 300 500 ^M
 many more rows here
 post_ivr_calls_handled Wisconsin 50 100 50 100 ^M
 post_ivr_calls_handled Wyoming 50 100 50 100 ^M

      [download]
[reply]
[d/l]
Re: Query about regular expression
by ww (Archbishop) on Sep 23, 2015 at 22:12 UTC

    If the line you want always begins <li>average_, then match on that (according to your taste, including or excluding the <li>s from your capture) rather than trying to count <li>s.

    If not, you'll have to use a more complex solution... for which you may wish to read in the regex docs about "positive look ahead" and variations.


    Spirit of the Monastery


[reply]
[d/l]
[select]
Re: Query about regular expression
by Anonymous Monk on Sep 24, 2015 at 00:35 UTC 
    #!/usr/bin/perl

# http://perlmonks.org/?node_id=1142838

use strict;
use warnings;
$| = 1;

$_ = join '', <DATA>;

my ($fourth) = /(?:.*?<li>(.*?)<\/li>){4}/s;

print "$fourth\n";

__DATA__
<ul>
<li><strong>site_user</strong></li>
<ul>
<li>user1</li>
</ul>
<li><strong>compare_hidden</strong></li>
<ul>
<li>average_speed_answer  25 60 30 60 ^M<br />
 calls_waiting  300 500 300 500 ^M<br />
 many more rows here
 post_ivr_calls_handled Wisconsin 50 100 50 100 ^M<br />
 post_ivr_calls_handled Wyoming 50 100 50 100 ^M<br />
</li>
<li><strong>calls_waiting_good_high</strong></li>
<ul>
<li>300</li>
</ul>
<li><strong>calls_waiting_warning_low</strong></li>
<ul>

    [download]

    Of course, this will have problems if you have nested li's

[reply]
[d/l]
Re: Query about regular expression
by Perl300 (Friar) on Sep 24, 2015 at 15:36 UTC
    Thanks for your suggestions Anonymous Monk, ww and jeffa. I had started with ww suggestion and modified by code as 
    if ( $form_dump_after =~ m{(<li>average_)(.*?)(</li>)}s ) {
        $inside_li = "average_".$2;
        print $fh "Value of \$inside_li: \n$inside_li \n";
    }

    [download]
    It gave me output as: 
    average_speed_answer  25 60 30 60 ^M<br />
 calls_waiting  300 500 300 500 ^M<br />
 many more rows here
 post_ivr_calls_handled Wisconsin 50 100 50 100 ^M<br />
 post_ivr_calls_handled Wyoming 50 100 50 100 ^M<br />

    [download]
    But I think I'll have to use HTML::TokeParser::Simple for the next tasks. I don't have HTML::TreeBuilder::XPath available and being in restricted env can't get it very easily, so can't check that out :-(
    Read more... (1360 Bytes)
[reply]
[d/l]
[select]

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