xmllint failing to properly query with xpath

I don't use xmllint, but I think the reason your XPath isn't working is because your doc.xml file is using a default namespace (http://purl.org/net/ulf/ns/0.4-02).

From what I can see, you have 2 options.

A. Use xmllint in shell mode and declare the namespace with a prefix. You can then use that prefix in your XPath.

    xmllint --shell doc.xml    / > setns x=http://purl.org/net/ulf/ns/0.4-02    / > xpath /x:chat

B. Use local-name() to match element names.

    xmllint --xpath /*[local-name()='chat']

You may also want to use namespace-uri()='http://purl.org/net/ulf/ns/0.4-02' along with local-name() so you are sure to return exactly what you are intending to return.

I realize this question is very old now, but in case it helps someone...

Had the same problem and it was due to the XML having a namespace (and sometimes it was duplicated in various places in the XML). Found it easiest to just remove the namespace before using xmllint:

sed -e 's/xmlns="[^"]*"//g' file.xml | xmllint --xpath "..." -

In my case the XML was UTF-16 so I had to convert to UTF-8 first (for sed):

iconv -f utf16 -t utf8 file.xml | sed -e 's/encoding="UTF-16"?>/encoding="UTF-8"?>/' | sed -e 's/xmlns="[^"]*"//g' | xmllint --xpath "..." -

If you're allowed to install powershell in your environment (it's also available for Linux), you can do it like this:

Select-Xml -XPath '/ns:chat' -Namespace $Namespace .\doc.xml | foreach { $_.Node }   xmlns   : http://purl.org/net/ulf/ns/0.4-02   account : foo@bar.com   service : MSN   event   : event   message : message

Of course all the same rules for xpath apply here. To access the text content of a node:

Select-Xml -XPath '/ns:chat/ns:message' -Namespace $Namespace .\doc.xml |foreach {$_.Node.InnerXML }<div xmlns="http://purl.org/net/ulf/ns/0.4-02"><span style="color: #000000; font-family: Helvetica; font-size: 12pt;">hi</span></div>

Or the content of the sender attribute:

Select-Xml -XPath '/ns:chat/ns:message/@sender' -Namespace $Namespace .\doc.xml |foreach {$_.Node }#text-----foo@bar.com