如何使用xmllint/xpath解析不同元素上几个属性的值? [英] How to parse out the value of several attributes on different elements with xmllint/xpath?

问题描述

对于给定的名为 configurations.xml 的xml文件，我想提取每个conf元素的 value ，并将其存储在变量中以备后用.

For a given xml file called configurations.xml I would like to extract the value of each conf element, and store it in a variable for later use.

<configurations>
  <conf name="bob"/>
  <conf name="alice"/>
  <conf name="ted"/>
  <conf name="carol"/>
</configurations>

预期输出为:

bob
ailce
ted
carol

我有 xpath 和 xmllint 可用. //conf/@name的xpath获取节点，但输出为name="bob"，这是我要避免的事情.

I have xpath and xmllint available. A xpath of //conf/@name gets the nodes, but outputs as name="bob", which is what I'm trying to avoid.

推荐答案

我不知道如何仅使用xmllint来实现您要实现的目标.

I don't know how to achieve what you're trying to achieve with xmllint only.

由于已安装xpath，所以您也安装了Perl的XML::XPath.那么一点点Perl:

Since you have xpath installed, you have Perl's XML::XPath too. So a little bit of Perl:

#!/usr/bin/perl

use XML::Path;

my $xp=XML::XPath->new(filename => 'configurations.xml');

my $nodeset=$xp->find('//conf/@name');
foreach my $node ($nodeset->get_nodelist) {
    print $node->getNodeValue,"\0";
}

将输出所需的内容，并用nil字符分隔.

will output what you want, separated with a nil character.

单线样式:

perl -mXML::XPath -e 'foreach $n (XML::XPath->new(filename => "configurations.xml")->find("//conf/\@name")->get_nodelist) { print $n->getNodeValue,"\0"; }'

例如在Bash数组中检索它们:

To retrieve them in, e.g., a Bash array:

#!/bin/bash

names=()
while IFS= read -r -d '' n; do
    names+=( "$n" )
done < <(
    perl -mXML::XPath -e 'foreach $n (XML::XPath->new(filename => "configurations.xml")->find("//conf/\@name")->get_nodelist) { print $n->getNodeValue,"\0" }'
)
# See what's in your array:
display -p names

请注意，此时您可以选择使用Perl并完全删除Bash来解决问题.

Note that at this point you have the option of turning to Perl and drop Bash completely to solve your problem.

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