在Perl中，XML :: Simple无法取消引用由Data :: Dumper解析的多维关联数组 [英] In Perl, XML::Simple is not able to dereference multi dimensional associative array parsed by Data::Dumper
问题描述
以下是我要解析的xml文件:
Following is the xml file that I want to parse:
<?xml version="1.0" encoding="UTF-8"?>
<topic id="yerus5" xmlns:ditaarch="http://dita.oasis-open.org/architecture/2005/">
<title/>
<shortdesc/>
<body>
<p><b>CCU_CNT_ADDR: (Address=0x004 Reset=32'h1)</b><table id="table_r5b_1xj_ts">
<tgroup cols="4">
<colspec colnum="1" colname="col1"/>
<colspec colnum="2" colname="col2"/>
<colspec colnum="3" colname="col3"/>
<colspec colnum="4" colname="col4"/>
<tbody>
<row>
<entry>Field</entry>
<entry>OFFSET</entry>
<entry>R/W Access</entry>
<entry>Description</entry>
</row>
<row>
<entry>reg2sm_cnt</entry>
<entry>15:0</entry>
<entry>R/W</entry>
<entry>Count Value to increment in the extenral memory at the specified location.
Default Value of 1. A Count value of 0 will clear the counter value</entry>
</row>
<row>
<entry>ccu2bus_endianess</entry>
<entry>24</entry>
<entry>R/W</entry>
<entry>Endianess of the data structure bit</entry>
</row>
<row>
<entry>ccu_lane_sel</entry>
<entry>25</entry>
<entry>R/W</entry>
<entry>ccu_lane_sel bit. Indicates the lane selection bit of the 32-bit location to
update</entry>
</row>
<row>
<entry>ccu_rdinvalid</entry>
<entry>26</entry>
<entry>R/W</entry>
<entry>ccu_rdinvalid bit. Indicates if the read value from the bus needs to be stored
or not.</entry>
</row>
</tbody>
</tgroup>
</table></p>
</body>
</topic>
运行以下代码后:
#!/usr/bin/perl
# use module
use XML::Simple;
use Data::Dumper;
# create object
$xml = new XML::Simple(); #(KeyAttr=>[]);
# read XML file
$data = $xml->XMLin("test.xml");
# access XML data
print Dumper($data);
# dereference hash ref
# foreach $b (@{$p->{b}})
# {
# }
foreach $body (@{$data->{body}})
{
foreach $p (@{$body->{p}})
{
foreach $table (@{$p->{table}})
{
foreach $tgroup (@{$table->{tgroup}})
{
foreach $tbody (@{$tgroup->{tbody}})
{
foreach $row (@{$tbody->{row}})
{
foreach $entry ((@{$row->{entry}})->[3])
{
print $entry,"\n";
}
}
}
}
}
}
}
我遇到此错误:在ppfe.pl第28行处没有数组引用.(在foreach $body (@{$data->{body}}))
我想访问<entry></entry>的每个数据.以上代码仅用于访问说明"列.该怎么做?
I want to access each data of the <entry></entry>. Above code only is only accessing the 'Description' column. How to do that?
关于上述问题，
我无法提取每个<b></b>文本的详细信息.以下是示例输出:
I am not able to extract details particularly for each <b></b> text. Following is sample output:
Name: CCU_CNT_ADDR: (Address=0x004 Reset=32'h1)
Field: reg2sm_cnt
OFFSET: 15:0
Access: R/W
Description: Count Value to increment in the extenral memory at the specified location. Default Value of 1. A Count value of 0 will clear the counter value
Filed: ccu2bus_endianess
OFFSET: 24
Access: R/W
Description: Endianess of the data structure bit
.
.
.
.
.
.
.
Name: CCU_STAT_ADDR: (Address=0x008 Reset=32'h0)
Field: fifo_cnt
.
.
.
.
.
.
.
推荐答案
请勿使用即使XML::Simple说不要使用XML::Simple".
不建议在新代码中使用此模块.提供了其他模块，它们提供了更直接，更一致的界面.
The use of this module in new code is discouraged. Other modules are available which provide more straightforward and consistent interfaces.
请尝试以下类似方法:
use strict;
use warnings;
use XML::Twig;
XML::Twig->new(
'twig_handlers' => {
'entry' => sub { print $_ ->text, "\n" }
}
)->parsefile ('your_file.xml');
这将打印所有entry元素的文本内容，这似乎是您要尝试执行的操作?
This will print the text content of all the entry elements, which appears to be what you're trying to do?
XML::Twig有两种非常方便的机制-一种使用twig_handler查找并打印符合规范的节点-这种按需使用"的功能在处理大型XML或要进行编辑时特别有用处理之前.
XML::Twig has two really handy mechanisms - one of using a twig_handler to find and print nodes matching a spec - this works 'as you go' which is particularly useful when handling large XML, or if you want to edit it before processing.
但是，它还允许您随后处理"数据:
However, it also allows you to 'handle' data afterwards:
my $twig = XML::Twig->new( 'pretty_print' => 'indented_a' )->parsefile('your_xml_file');
foreach my $element ( $twig -> get_xpath ("//entry") )
{
print $element ->text, "\n";
}
或者您可以像上面一样使用节点的完整路径:
Or you could use a full path to the node as you're doing above:
$twig->root->get_xpath("body/p/table/tgroup/tbody/row/entry") )
不过是针对您的问题:
仅上述代码仅访问说明"列.该怎么做?
Above code only is only accessing the 'Description' column. How to do that?
那是因为您正在这样做:
That's because you're doing this:
foreach $entry ((@{$row->{entry}})->[3])
例如尝试获取entry数组中的第4个元素，即Description.
E.g. trying to get the 4th element in the entry array, which is Description.
参考注释-我建议您将条目"转换为XML数据结构之外的哈希.
With reference to the comments - I'd suggest you convert your 'entries' into a hash outside the XML data structure.
赞:
use strict;
use warnings;
use XML::Twig;
use Data::Dumper;
my @headers;
my $column_to_show = 'Field';
sub process_row {
my %entries;
my ( $twig, $row ) = @_;
my @row_entries = map { $_->text } $row->children;
if (@headers) {
@entries{@headers} = @row_entries;
print $column_to_show, " => ", $entries{$column_to_show}, "\n";
}
else {
@headers = @row_entries;
}
}
my $twig = XML::Twig->new(
'pretty_print' => 'indented_a',
twig_handlers => { 'row' => \&process_row }
)->parsefile ( 'your_file.xml' );
这是什么:
- 在每个
row元素上触发该处理程序. - 将
entry子元素(及其文本)提取到数组中.@row_entries. - 使用标题"行将其转换为哈希.
- 打印与特定键
$column_to_show匹配的哈希值.
- fire that handler on each
rowelement. - extract the
entrysubelements (and their text) into an array.@row_entries. - Use the "header" row to turn that into a hash.
- Print the hash value that matches a specific key
$column_to_show.
根据是否要处理数据而不是打印数据，可以将其转换为数组或类似的哈希.
Depending on whether you're doing any more with the data than print it, you can turn that into a hash of arrays or similar.
或者您可以只打印$row_entries[3]而不是当然;).
Or you could just print $row_entries[3] instead of course ;).
这篇关于在Perl中，XML :: Simple无法取消引用由Data :: Dumper解析的多维关联数组的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
