title: How to Use Functions in Xpath 1.0
body: <p>Im using xmllint --xpath which supports only XPath 1.0.
  I know XPath 1.0 supports functions like concat() : <a href="https://www.w3.org/TR/1999/REC-xpath-19991116/" rel="nofollow noreferrer">https://www.w3.org/TR/1999/REC-xpath-19991116/</a></p>
  <p>But I get errors like below when I try to use them in an XPath in orders to extract content from an xml document :</p>
  <pre><code>xmllint --debug --xpath &quot;//*[local-name()='artifactId' and contains(text(),'log4j')]/../concat(groupId/text(),' ',artifactId/text(),' ', version/text())&quot; ~/aax1
  
  XPath error : Invalid expression
  //*[local-name()='artifactId' and contains(text(),'log4j')]/../concat(groupId/text(),' ',artifactId/text(),' ', version/text())
  
  xmlXPathEval: evaluation failed
  XPath evaluation failure
  </code></pre>
  <p>I was reading the XPath specification. It is not clear how these functions can be used in an XPath expression ( It is clear how to use them in XSLT ). Is it possible to use them in XPath 1.0 outside the predicate ?</p>