带有XPATH的Linux Bash XMLLINT [英] Linux Bash XMLLINT with XPATH

问题描述

今天，我开始学习如何正确使用xmllint.它似乎没有被很好地覆盖或解释.我计划使用一个语言资源文件来运行我的整个系统.我混合了bash脚本和php页面，必须从该语言文件中读取.

Today I get to learn how to use xmllint properly. It does not seem to be well covered or explained. I plan to use a single language resource file to run my entire system. I have a mixture of bash scripts and php pages that must read from this language file.

当前，我在xml文件en.xml中使用以下格式:

Currently I am using the following format in my xml file en.xml:

<?xml version="1.0" encoding="utf-8"?>
<resources>

   <item id="index.php">
        <label>LABEL</label>
        <value>VALUE</value>
        <description>DESCRIPTION</description>
   </item>
   <item id="config.php">
        <label>LABEL</label>
        <value>VALUE</value>
        <description>DESCRIPTION</description>
   </item>

</resources>

现在，我需要从bash脚本行开始，该行应从xml文件中提取数据值.例如，我想从index.php项目中获取DESCRIPTION的值.

Now I need to start with a bash script line that should pull the data values from the xml file. For example I want to get the value of DESCRIPTION from the index.php item.

我正在使用

xmllint --xpath 'string(//description)' /path/en.xml

对于可以使用的其他布局，但是现在我更改了xml文件的布局，我迷失了如何最好地定位特定的<item>，然后在bash脚本中向下钻取其子元素.

for a different layout which worked, but now that I am changing the layout of my xml file, I am lost as to how best to target a specific <item> and then drill down to its child element in the bash script.

有人可以帮助xmllint --xpath行获得此值吗?

Can someone help with a xmllint --xpath line to get this value please?

推荐答案

如何最好地定位特定对象，然后深入到其子元素

how best to target a specific and then drill down to its child element

正确的XPath表达式是:

The correct XPath expression to do this is:

/resources/item[@id="index.php"]/description/text()

以简单的英语:从文档节点开始，到文档元素resources，再到其子元素item，但仅当id属性的值为"index.php"时，再到其元素子description并检索其文本值.

In plain English: Start from the document node, to the document element resources, on to its child item, but only if the value of the id attribute is "index.php", on to its child description and retrieve its textual value.

我使用xmllint来验证XML文档，但从未使用过路径表达式.在bash shell(至少在Mac OS中)中，有一个甚至更简单的工具来评估XPath表达式，称为"xpath":

I use xmllint to validate XML documents, but never for path expressions. In a bash shell (at least with Mac OS) there is an even simpler tool for evaluating XPath expressions, called "xpath":

$ xpath en.xml '/resources/item[@id="index.php"]/description/text()'

然后，获得以下结果:

Found 1 nodes:
-- NODE --
DESCRIPTION

---

如果您仍然喜欢xmllint，请按以下方式使用它:

---

If you still prefer xmllint, use it in the following way:

$ xmllint --xpath '/resources/item[@id="index.php"]/description/text()' en.xml > result.txt

默认情况下，--xpath表示--noout，这可防止xmllint输出任何内容.将输出重定向到文件.

By default, --xpath implies --noout, which prevents xmllint from outputting anything. Redirect the output to a file.

$ cat result.txt 
DESCRIPTION

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