How to execute XPath one-liners from shell?

You should try these tools :

xmlstarlet : can edit, select, transform... Not installed by default, xpath1

xmllint : often installed by default with libxml2-utils, xpath1 (check my wrapper to have --xpath switch on very old releases and newlines delimited output (v < 2.9.9)

xpath : installed via perl's module XML::XPath, xpath1

xml_grep : installed via perl's module XML::Twig, xpath1 (limited xpath usage)

xidel: xpath3

saxon-lint : my own project, wrapper over @Michael Kay's Saxon-HE Java library, xpath3

xmllint comes with libxml2-utils (can be used as interactive shell with the --shell switch)

xmlstarlet is xmlstarlet.

xpath comes with perl's module XML::Xpath

xml_grep comes with perl's module XML::Twig

xidel is xidel

saxon-lint using SaxonHE 9.6 ,XPath 3.x (+retro compatibility)

Ex :

xmllint --xpath '//element/@attribute' file.xml
xmlstarlet sel -t -v "//element/@attribute" file.xml
xpath -q -e '//element/@attribute' file.xml
xidel -se '//element/@attribute' file.xml
saxon-lint --xpath '//element/@attribute' file.xml

xmlstarlet page

man xmllint

xpath page

xml_grep

xidel

saxon-lint

.

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You can also try my Xidel. It is not in a package in the repository, but you can just download it from the webpage (it has no dependencies).

It has simple syntax for this task:

xidel filename.xml -e '//element/@attribute' 

And it is one of the rare of these tools that supports XPath 2.

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One package that is very likely to be installed on a system already is python-lxml. If so, this is possible without installing any extra package:

python -c "from lxml.etree import parse; from sys import stdin; print('\n'.join(parse(stdin).xpath('//element/@attribute')))"

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In my search to query maven pom.xml files I ran accross this question. However I had the following limitations:

must run cross-platform.

must exist on all major linux distributions without any additional module installation

must handle complex xml-files such as maven pom.xml files

simple syntax

I have tried many of the above without success:

python lxml.etree is not part of the standard python distribution

xml.etree is but does not handle complex maven pom.xml files well, have not digged deep enough

python xml.etree does not handle maven pom.xml files for unknown reason

xmllint does not work either, core dumps often on ubuntu 12.04 "xmllint: using libxml version 20708"

The solution that I have come across that is stable, short and work on many platforms and that is mature is the rexml lib builtin in ruby:

ruby -r rexml/document -e 'include REXML; 
     puts XPath.first(Document.new($stdin), "/project/version/text()")' < pom.xml

What inspired me to find this one was the following articles:

Ruby/XML, XSLT and XPath Tutorial

IBM: Ruby on Rails and XML

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Saxon will do this not only for XPath 2.0, but also for XQuery 1.0 and (in the commercial version) 3.0. It doesn't come as a Linux package, but as a jar file. Syntax (which you can easily wrap in a simple script) is

java net.sf.saxon.Query -s:source.xml -qs://element/attribute

2020 UPDATE

Saxon 10.0 includes the Gizmo tool, which can be used interactively or in batch from the command line. For example

java net.sf.saxon.Gizmo -s:source.xml
/>show //element/@attribute
/>quit

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You might also be interested in xsh. It features an interactive mode where you can do whatever you like with the document:

open 1.xml ;
ls //element/@id ;
for //p[@class="first"] echo text() ;

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clacke’s answer is great but I think only works if your source is well-formed XML, not normal HTML.

So to do the same for normal Web content—HTML docs that aren’t necessarily well-formed XML:

echo "<p>foo<div>bar</div><p>baz" | python -c "from sys import stdin; \
from lxml import html; \
print '\n'.join(html.tostring(node) for node in html.parse(stdin).xpath('//p'))"

And to instead use html5lib (to ensure you get the same parsing behavior as Web browsers—because like browser parsers, html5lib conforms to the parsing requirements in the HTML spec).

echo "<p>foo<div>bar</div><p>baz" | python -c "from sys import stdin; \
import html5lib; from lxml import html; \
doc = html5lib.parse(stdin, treebuilder='lxml', namespaceHTMLElements=False); \
print '\n'.join(html.tostring(node) for node in doc.xpath('//p'))

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Similar to Mike's and clacke's answers, here is the python one-liner (using python >= 2.5) to get the build version from a pom.xml file that gets around the fact that pom.xml files don't normally have a dtd or default namespace, so don't appear well-formed to libxml:

python -c "import xml.etree.ElementTree as ET; \
  print(ET.parse(open('pom.xml')).getroot().find('\
  {http://maven.apache.org/POM/4.0.0}version').text)"

Tested on Mac and Linux, and doesn't require any extra packages to be installed.

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In addition to XML::XSH and XML::XSH2 there are some grep-like utilities suck as App::xml_grep2 and XML::Twig (which includes xml_grep rather than xml_grep2). These can be quite useful when working on a large or numerous XML files for quick oneliners or Makefile targets. XML::Twig is especially nice to work with for a perl scripting approach when you want to a a bit more processing than your $SHELL and xmllint xstlproc offer.

The numbering scheme in the application names indicates that the "2" versions are newer/later version of essentially the same tool which may require later versions of other modules (or of perl itself).

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It bears mentioning that nokogiri itself ships with a command line tool, which should be installed with gem install nokogiri.

You might find this blog post useful.

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I've tried a couple of command line XPath utilities and when I realized I am spending too much time googling and figuring out how they work, so I wrote the simplest possible XPath parser in Python which did what I needed.

The script below shows the string value if the XPath expression evaluates to a string, or shows the entire XML subnode if the result is a node:

#!/usr/bin/env python
import sys
from lxml import etree

tree = etree.parse(sys.argv[1])
xpath = sys.argv[2]

for e in tree.xpath(xpath):

    if isinstance(e, str):
        print(e)
    else:
        print((e.text and e.text.strip()) or etree.tostring(e))

It uses lxml — a fast XML parser written in C which is not included in the standard python library. Install it with pip install lxml. On Linux/OSX might need prefixing with sudo.

Usage:

python xmlcat.py file.xml "//mynode"

lxml can also accept an URL as input:

python xmlcat.py http://example.com/file.xml "//mynode" 

Extract the url attribute under an enclosure node i.e. <enclosure url="http:...""..>):

python xmlcat.py xmlcat.py file.xml "//enclosure/@url"

Xpath in Google Chrome

As an unrelated side note: If by chance you want to run an XPath expression against the markup of a web page then you can do it straight from the Chrome devtools: right-click the page in Chrome > select Inspect, and then in the DevTools console paste your XPath expression as $x("//spam/eggs").

Get all authors on this page:

$x("//*[@class='user-details']/a/text()")

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Here's one xmlstarlet use case to extract data from nested elements elem1, elem2 to one line of text from this type of XML (also showing how to handle namespaces):

<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>
<mydoctype xmlns="http://xml-namespace-uri" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xml-namespace-uri http://xsd-uri" format="20171221A" date="2018-05-15">

  <elem1 time="0.586" length="10.586">
      <elem2 value="cue-in" type="outro" />
  </elem1>

</mydoctype>

The output will be

0.586 10.586 cue-in outro

In this snippet, -m matches the nested elem2, -v outputs attribute values (with expressions and relative addressing), -o literal text, -n adds a newline:

xml sel -N ns="http://xml-namespace-uri" -t -m '//ns:elem1/ns:elem2' \
 -v ../@time -o " " -v '../@time + ../@length' -o " " -v @value -o " " -v @type -n file.xml

If more attributes are needed from elem1, one can do it like this (also showing the concat() function):

xml sel -N ns="http://xml-namespace-uri" -t -m '//ns:elem1/ns:elem2/..' \
 -v 'concat(@time, " ", @time + @length, " ", ns:elem2/@value, " ", ns:elem2/@type)' -n file.xml

Note the (IMO unnecessary) complication with namespaces (ns, declared with -N), that had me almost giving up on xpath and xmlstarlet, and writing a quick ad-hoc converter.

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My Python script xgrep.py does exactly this. In order to search for all attributes attribute of elements element in files filename.xml ..., you would run it as follows:

xgrep.py "//element/@attribute" filename.xml ...

There are various switches for controlling the output, such as -c for counting matches, -i for indenting the matching parts, and -l for outputting filenames only.

The script is not available as a Debian or Ubuntu package, but all of its dependencies are.

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Install the BaseX database, then use it's "standalone command-line mode" like this:

basex -i - //element@attribute < filename.xml

or

basex -i filename.xml //element@attribute

The query language is actually XQuery (3.0), not XPath, but since XQuery is a superset of XPath, you can use XPath queries without ever noticing.

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Since this project is apparently fairly new, check out https://github.com/jeffbr13/xq , seems to be a wrapper around lxml, but that is all you really need (and posted ad hoc solutions using lxml in other answers as well)

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I wasn't happy with Python one-liners for HTML XPath queries, so I wrote my own. Assumes that you installed python-lxml package or ran pip install --user lxml:

function htmlxpath() { python -c 'for x in __import__("lxml.html").html.fromstring(__import__("sys").stdin.read()).xpath(__import__("sys").argv[1]): print(x)' $1 }

Once you have it, you can use it like in this example:

> curl -s https://slashdot.org | htmlxpath '//title/text()'
Slashdot: News for nerds, stuff that matters

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Sorry to be yet another voice in the fray. I tried all the tools in this thread and found none of them to be satisfactory for my needs, so I wrote my own. You can find it here: https://github.com/charmparticle/xpe

It's been uploaded to pypi, so you can easily install it with pip3 like so:

sudo pip3 install xpe

Once installed, you can use it to run xpath expressions against various kinds of input with the same level of flexibility you would get from using xpaths in selenium or javascript. Yeah, you can use xpaths against HTML with this.

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A solution that works even when namespace declarations exist on top:

Most of the commands proposed in the answers do not work out of the box if the xml has a namespace declared on top. Consider this:

input xml:

<elem1 xmlns="urn:x" xmlns:prefix="urn:y">
    <elem2 attr1="false" attr2="value2">
        elem2 value
    </elem2>
    <elem2 attr1="true" attr2="value2.1">
        elem2.1 value
    </elem2>    
    <prefix:elem3>
        elem3 value
    </prefix:elem3>        
</elem1>

Does not work:

xmlstarlet sel -t -v "/elem1" input.xml
# nothing printed
xmllint -xpath "/elem1" input.xml
# XPath set is empty

Solution:

# Requires >=java11 to run like below (but the code requires >=java17 for case syntax to be recognized)

# Prints the whole document
java ExtractXpath.java "/" example-inputs/input.xml

# Prints the contents and self of "elem1"
java ExtractXpath.java "/elem1" input.xml

# Prints the contents and self of "elem2" whose attr2 value is: 'value2'
java ExtractXpath.java "//elem2[@attr2='value2']" input.xml

# Prints the value of the attribute 'attr2': "value2", "value2.1"
java ExtractXpath.java "/elem1/elem2/@attr2" input.xml

# Prints the text inside elem3: "elem3 value"
java ExtractXpath.java "/elem1/elem3/text()" input.xml

# Prints the name of the matched element: "prefix:elem3"
java ExtractXpath.java "name(/elem1/elem3)" input.xml
# Same as above: "prefix:elem3"
java ExtractXpath.java "name(*/elem3)" input.xml

# Prints the count of the matched elements: 2.0
java ExtractXpath.java "count(/elem2)" input.xml


# known issue: while "//elem2" works. "//elem3" does not (it works only with: '*/elem3' )

ExtractXpath.java:

import java.io.File;
import java.io.FileInputStream;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.stream.Collectors;

import javax.xml.XMLConstants;
import javax.xml.namespace.NamespaceContext;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathEvaluationResult;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;

import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

public class ExtractXpath {

    public static void main(String[] args) throws Exception {
        assertThat(args.length==2, "Wrong number of args");
        String xpath = args[0];
        File file = new File(args[1]);
             
        assertThat(file.isFile(), file.getAbsolutePath()+" is not a file.");
        FileInputStream fileIS = new FileInputStream(file);
        DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder builder = builderFactory.newDocumentBuilder();
        Document xmlDocument = builder.parse(fileIS);
        XPath xPath = XPathFactory.newInstance().newXPath();
        String expression = xpath;
        XPathExpression xpathExpression =  xPath.compile(expression);
        
        XPathEvaluationResult xpathEvalResult =  xpathExpression.evaluateExpression(xmlDocument);
        System.out.println(applyXpathExpression(xmlDocument, xpathExpression, xpathEvalResult.type().name()));
    }

    private static String applyXpathExpression(Document xmlDocument, XPathExpression expr, String xpathTypeName) throws TransformerConfigurationException, TransformerException, XPathExpressionException {

        // see: https://www.w3.org/TR/1999/REC-xpath-19991116/#corelib
        List<String> retVal = new ArrayList();
        if(xpathTypeName.equals(XPathConstants.NODESET.getLocalPart())){ //e.g. xpath: /elem1/*
            NodeList nodeList = (NodeList)expr.evaluate(xmlDocument, XPathConstants.NODESET);
            for (int i = 0; i < nodeList.getLength(); i++) {
                retVal.add(convertNodeToString(nodeList.item(i)));
            }
        }else if(xpathTypeName.equals(XPathConstants.STRING.getLocalPart())){ //e.g. xpath: name(/elem1/*)
            retVal.add((String)expr.evaluate(xmlDocument, XPathConstants.STRING));
        }else if(xpathTypeName.equals(XPathConstants.NUMBER.getLocalPart())){ //e.g. xpath: count(/elem1/*)
            retVal.add(((Number)expr.evaluate(xmlDocument, XPathConstants.NUMBER)).toString());
        }else if(xpathTypeName.equals(XPathConstants.BOOLEAN.getLocalPart())){ //e.g. xpath: contains(elem1, 'sth')
            retVal.add(((Boolean)expr.evaluate(xmlDocument, XPathConstants.BOOLEAN)).toString());
        }else if(xpathTypeName.equals(XPathConstants.NODE.getLocalPart())){ //e.g. xpath: fixme: find one
            System.err.println("WARNING found xpathTypeName=NODE");
            retVal.add(convertNodeToString((Node)expr.evaluate(xmlDocument, XPathConstants.NODE)));
        }else{
            throw new RuntimeException("Unexpected xpath type name: "+xpathTypeName+". This should normally not happen");
        }
        return retVal.stream().map(str->"==MATCH_START==\n"+str+"\n==MATCH_END==").collect(Collectors.joining ("\n"));
        
    }
    
    private static String convertNodeToString(Node node) throws TransformerConfigurationException, TransformerException {
            short nType = node.getNodeType();
        switch (nType) {
            case Node.ATTRIBUTE_NODE , Node.TEXT_NODE -> {
                return node.getNodeValue();
            }
            case Node.ELEMENT_NODE, Node.DOCUMENT_NODE -> {
                StringWriter writer = new StringWriter();
                Transformer trans = TransformerFactory.newInstance().newTransformer();
                trans.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
                trans.setOutputProperty(OutputKeys.INDENT, "yes");
                trans.transform(new DOMSource(node), new StreamResult(writer));
                return writer.toString();
            }
            default -> {
                System.err.println("WARNING: FIXME: Node type:"+nType+" could possibly be handled in a better way.");
                return node.getNodeValue();
            }
                
        }
    }

    
    private static void assertThat(boolean b, String msg) {
        if(!b){
            System.err.println(msg+"\n\nUSAGE: program xpath xmlFile");
            System.exit(-1);
        }
    }
}

@SuppressWarnings("unchecked")
class NamespaceResolver implements NamespaceContext {
    //Store the source document to search the namespaces
    private final Document sourceDocument;
    public NamespaceResolver(Document document) {
        sourceDocument = document;
    }

    //The lookup for the namespace uris is delegated to the stored document.
    @Override
    public String getNamespaceURI(String prefix) {
        if (prefix.equals(XMLConstants.DEFAULT_NS_PREFIX)) {
            return sourceDocument.lookupNamespaceURI(null);
        } else {
            return sourceDocument.lookupNamespaceURI(prefix);
        }
    }

    @Override
    public String getPrefix(String namespaceURI) {
        return sourceDocument.lookupPrefix(namespaceURI);
    }

    @SuppressWarnings("rawtypes")
    @Override
    public Iterator getPrefixes(String namespaceURI) {
        return null;
    }
}

and for simplicity:

xpath-extract command:

#!/bin/bash
java ExtractXpath.java "$1" "$2"

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