如何使用cmdlet Select-Xml交互式提示符？

Question

Select-Xml的用法如下：

PS /home/nicholas/powershell> 
PS /home/nicholas/powershell> Select-Xml

cmdlet Select-Xml at command pipeline position 1
Supply values for the following parameters:
Xml[0]: ./bookstore.xml
Xml[1]: 
XPath: /bookstore
Select-Xml: Cannot bind parameter 'Xml'. Cannot convert the "./bookstore.xml" value of type "System.String" to type "System.Xml.XmlNode".
PS /home/nicholas/powershell> 

如上所述，通过REPL输入参数和Xpath。当然：

PS /home/nicholas/powershell> 
PS /home/nicholas/powershell> $doc = New-Object xml                                                                   
PS /home/nicholas/powershell> 
PS /home/nicholas/powershell> $doc.Load( (Resolve-Path ./bookstore.xml) )                                             
PS /home/nicholas/powershell> 
PS /home/nicholas/powershell> Select-Xml "./bookstore.xml" -XPath "/bookstore/book/title" | foreach {$_.node.InnerXML}
Pride And Prejudice
The Handmaid's Tale
Emma
Sense and Sensibility
PS /home/nicholas/powershell> 
PS /home/nicholas/powershell> cat ./bookstore.xml
<?xml version="1.0"?>
<!-- A fragment of a book store inventory database -->
<bookstore xmlns:bk="urn:samples">
  <book genre="novel" publicationdate="1997" bk:ISBN="1-861001-57-8">
    <title>Pride And Prejudice</title>
    <author>
      <first-name>Jane</first-name>
      <last-name>Austen</last-name>
    </author>
    <price>24.95</price>
  </book>
  <book genre="novel" publicationdate="1992" bk:ISBN="1-861002-30-1">
    <title>The Handmaid's Tale</title>
    <author>
      <first-name>Margaret</first-name>
      <last-name>Atwood</last-name>
    </author>
    <price>29.95</price>
  </book>
  <book genre="novel" publicationdate="1991" bk:ISBN="1-861001-57-6">
    <title>Emma</title>
    <author>
      <first-name>Jane</first-name>
      <last-name>Austen</last-name>
    </author>
    <price>19.95</price>
  </book>
  <book genre="novel" publicationdate="1982" bk:ISBN="1-861001-45-3">
    <title>Sense and Sensibility</title>
    <author>
      <first-name>Jane</first-name>
      <last-name>Austen</last-name>
    </author>
    <price>19.95</price>
  </book>
</bookstore>

PS /home/nicholas/powershell> 

works fine。

这个问题经过了大量的编辑。

我并不期望交互式提示符被广泛使用。

如果有人使用它，那太好了。否则，这个问题的答案就是为了我的目的。

Answer 1

交互式提示符并不是最好的。正如文档所述，-Xml请求xml类型的对象，而-Path只请求文件名。有不同的参数集。按此顺序，参数名称是可选的。如果xpath包含方括号，则必须将其引起来。

[xml]$xml = get-content bookstore.xml
select-xml -XPath /bookstore/book/title -Xml $xml

Node  Path        Pattern
----  ----        -------
title InputStream /bookstore/book/title
title InputStream /bookstore/book/title
title InputStream /bookstore/book/title
title InputStream /bookstore/book/title


select-xml -XPath /bookstore/book/title -Path bookstore.xml

Node  Path                                Pattern
----  ----                                -------
title C:\Users\ccfadmin\foo\bookstore.xml /bookstore/book/title
title C:\Users\ccfadmin\foo\bookstore.xml /bookstore/book/title
title C:\Users\ccfadmin\foo\bookstore.xml /bookstore/book/title
title C:\Users\ccfadmin\foo\bookstore.xml /bookstore/book/title

使用管道：

# piping to -Content, it has to be one whole string
get-content -raw bookstore.xml | select-xml //title

$xml | select-xml //title