Search XML Attributes PowerShell XPath

Extensible Markup Language (XML) is a plain text format that is used to store structured data. XML is written to be both human and machine-readable.

XML documents often begin with a declaration, as shown here:

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

The Select-Xml command may be used to search XML documents using the XPath query language. PowerShell v3 and later also include a Select-Xml cmdlet. This cmdlet is designed to find text within an XML string or within an XML document. Specifically, it’s designed to execute XPath queries.

In this Powershell tutorial on XML, we will discuss how to search XML and extract specific nodes, by searching XML attributes. We will use the select-Xml cmdlet for doing this, however, the XPath query would be at an attribute level. Using the examples provided in this tutorial, you should be able to easily query XML data in Powershell and use the output values.

1. Input XML with Attributes

Use the following input XML for this tutorial:

<Details>
        <department count="10">
                <ID>10</ID>
                <dname>Administration</dname>
                <manager>200</manager>
                <location>1700</location>
                <revenue>77</revenue>
        </department>
        <department count="20">
                <ID>20</ID>
                <dname>Marketing</dname>
                <manager>201</manager>
                <location>1800</location>
                <revenue>50</revenue>
        </department>
</Details>

2. Load the XML in PowerShell

We will load the XML directly in PowerShell as shown in the illustration below:

PS C:\> $xml_attributes=@"
>> <Details>
>>     <department count="10">
>>         <ID>10</ID>
>>         <dname>Administration</dname>
>>         <manager>200</manager>
>>         <location>1700</location>
>>         <revenue>77</revenue>
>>     </department>
>>     <department count="20">
>>         <ID>20</ID>
>>         <dname>Marketing</dname>
>>         <manager>201</manager>
>>         <location>1800</location>
>>         <revenue>50</revenue>
>>     </department>
>> </Details>
>> "@
>>
PS C:\>

The variable xml_attributes contains the XML data that we can search upon using select-Xml cmdlet.

3. Search XML by Attributes in PowerShell – XPath

If you want to list all the “count” attribute values as an example, you can do this as per the command below.

C:\>powershell
Windows PowerShell
Copyright (C) 2009 Microsoft Corporation. All rights reserved.

PS C:\> Select-Xml -Content $xml_attributes -XPath '//@count' | foreach {$_.node
}

#text
-----
10
20

Here, we use ‘//’ to directly query the XML attribute and use the ‘foreach’ statement to print the value in Powershell.

4. List XML Nodes Matching Attribute Value – Example

In this case, the requirement is to list all the department details where the count matches 10. You can do this easily by matching the attribute value to 10 in the XPath and printing the output. The Powershell command to do this is provided below:

PS C:\> Select-Xml -Content $xml_attributes -XPath '//department[@count="10"]' |
 foreach {$_.node}


count    : 10
ID       : 10
dname    : Administration
manager  : 200
location : 1700
revenue  : 77

Summary

XML is easy to work with. It can be used for configuration and data storage. You’ve seen how to manually set up a starting document, load it into the shell, and enumerate its elements. XPath can be used to navigate or search an XML document. PowerShell (and .NET) uses XPath 1.0.