3

试图制作一个 Perl 脚本来打开一个 HTML 文件并提取<span class="postertrip">标签中包含的任何内容。

示例 HTML：

<table>
   <tbody>
      <tr>
         <td class="doubledash">&gt;&gt;</td>
         <td class="reply" id="reply2">
            <a name="2"></a> <label><input type="checkbox" name="delete" value="1199313466,2" /> <span class="replytitle"></span> <span class="commentpostername"><a href="test">Test1</a></span><span class="postertrip"><a href="test">!AAAAAAAA</a></span>  08/01/03(Thu)02:06</label> <span class="reflink"> <a href="test">No.2</a> </span>&nbsp;  <br /> <span class="filesize">File: <a target="_blank" href="test">1199326003295.jpg</a> -(<em>65843 B, 288x412</em>)</span> <span class="thumbnailmsg">Thumbnail displayed, click image for full size.</span><br />  <a target="_blank" test"> <img src="test" width="139" height="200" alt="65843" class="thumb" /></a>    
            <blockquote>
               <p>Test message 1</p>
            </blockquote>
         </td>
      </tr>
   </tbody>
</table>
<table>
   <tbody>
      <tr>
         <td class="doubledash">&gt;&gt;</td>
         <td class="reply" id="reply5">
            <a name="5"></a> <label><input type="checkbox" name="delete" value="1199313466,5" /> <span class="replytitle"></span>  <span class="commentpostername">Test2</span><span class="postertrip">!BBBBBBBB</span> 08/01/03(Thu)16:12</label> <span class="reflink"> <a href="test">No.5</a> </span>&nbsp;  
            <blockquote>
               <p>Test message 2</p>
            </blockquote>
         </td>
      </tr>
   </tbody>
</table>
<table>
   <tbody>
      <tr>
         <td class="doubledash">&gt;&gt;</td>
         <td class="reply" id="reply7">
            <a name="7"></a> <label><input type="checkbox" name="delete" value="1199161229,7" /> <span class="replytitle"></span>  <span class="commentpostername">Test3</span><span class="postertrip">!CCCCCCCC.</span> 08/01/01(Tue)17:53</label> <span class="reflink"> <a href="test">No.7</a> </span>&nbsp;  
            <blockquote>
               <p>Test message 3</p>
            </blockquote>
         </td>
      </tr>
   </tbody>
</table>

期望的输出：

!AAAAAAAA
!BBBBBBBB
!CCCCCCCC

当前脚本：

#!/usr/bin/env perl

use warnings;
use strict;
use 5.010;

use HTML::TreeBuilder;


open(my $html, "<", "temp.html")
        or die "Can't open";


my $tree = HTML::TreeBuilder->new();
$tree->parse_file($html);


foreach my $e ($tree->look_down('class', 'reply')) {
    my $e = $tree->look_down('class', 'postertrip');
    say $e->as_text;
}

脚本输出错误：

!AAAAAAAA
!AAAAAAAA
!AAAAAAAA
4

2 回答 2

5

在您的 foreach 循环中，您必须从找到的元素向下看。所以正确的代码是：

foreach my $parent ($tree->look_down('class', 'reply')) {
    my $e = $parent->look_down('class', 'postertrip');
    say $e->as_text;
}
于 2020-06-07T08:09:48.323 回答
5

我从不喜欢 HTML::TreeBuilder。有点复杂，三年没更新了。不过，在Mojo::DOM中使用 CSS 选择器非常简单。它完成了各种s 所做find的所有工作：look_down

use v5.10;
use Mojo::DOM;

my $html = do { local $/; <DATA> };

my @values = Mojo::DOM->new( $html )
    ->find( 'td.reply span.postertrip' )
    ->map( 'all_text' )
    ->each;

say join "\n", @values;

请注意，在您的 HTML::TreeBuilder 代码中，您没有选择您关心的标签的逻辑。你可以做到，但你需要额外的工作。CSS 选择器会为您解决这个问题。

于 2020-06-07T08:10:08.020 回答