parsing xml with xmlstarlet and specific attribute

Question

I've tried to use xmlstarlet and am having difficulty. I have the following XML feed.

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<RESPONSE VERSION="L100" REQUEST="show volume-statistics">
  <OBJECT basetype="volume-statistics" name="volume-statistics" oid="1" format="rows">
    <PROPERTY name="volume-name" display-name="Name">VOL0</PROPERTY>
    <PROPERTY name="volume-IOPS" display-name="IOPS">100</PROPERTY>
  </OBJECT>
</RESPONSE>

I need to select the IOPS value where the name is equal to VOL0 and print only the value of the volume-IOPS.

I have tried following Commands:

xmlstarlet sel -t -m "RESPONSE/OBJECT/PROPERTY/[@display-name='VOL0']" -v "RESPONSE/OBJECT/PROPERTY[@volume0IOPS] test.xml

Example Output

100

Answer 1

You can do this with a single XPath expression, that retrieves the <OBJECT/> element which contains the "VOL0" name property, and then selects the respective IOPS property.

xmlstarlet sel -t -v '
  /RESPONSE/OBJECT[PROPERTY[@name="volume-name"]="VOL0"]
  /PROPERTY[@name="volume-IOPS"]' test.xml