I'm trying to extract the contents of the 'coordinates' node in this KML file using xmlstarlet.
The KML file validates fine using xmlstarlet itself.
I've whittled it down to a small test file containing:
<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://earth.google.com/kml/2.2">
<Document>
<Placemark>
<name>eurovelo-5 690</name>
<Snippet></Snippet>
<description><![CDATA[ ]]></description>
<styleUrl>#style390</styleUrl>
<LineString>
<tessellate>1</tessellate>
<coordinates>
10.146948,44.790592,97.500000
10.146958,44.790562,97.599998
10.147018,44.790497,97.699997
10.147083,44.790466,97.699997
</coordinates>
</LineString>
</Placemark>
</Document>
</kml>
Running this query fails though:
xmlstarlet sel -t -c "//coordinates/text()" test.kml
This appears to parse correctly using the online path tool - http://www.qutoric.com/xslt/analyser/xpathtool.html
Am I missing something here?
You need to define and use a namespace prefix for http://earth.google.com/kml/2.2 test.kml - something like this:
xmlstarlet sel -t -c "//kml:coordinates/text()" -N kml=http://earth.google.com/kml/2.2 test.kml
XPaths do not have a default namespace - if a name in a XPath does not specify a namespace prefix it is assumed to be in the null namespace; hence it is necessary to always specify a namespace prefix when trying to match nodes whose names are in a namespace different from the null one (as in this case).
来源：https://stackoverflow.com/questions/16306695/why-does-this-xpath-expression-not-return-the-correct-value-in-xmlstarlet