xmlstarlet

How to use XMLStarlet to lookup values in a second file

Let's assume we have two directories:

/home/a
/home/b

In directory a with have lots of XML files like this:

<root>
  <id>87182378127381273</id>
  <name>just a name</name>
</root>

and for each of the id we find an XML file in directory b, like:

/home/b/87182378127381273.xml
...

and in that file we have for instance:

<root>
  <counter1>879</counter1>
</root>

And now I just want to run an xmlstarlet command that outputs the following for each found XML in directory a:

87182378127381273,just a name,879
...

I tried to solve this by this xmlstarlet command:

find . -iname '*.xml' | xargs xmlstarlet sel \
  -t -m "/root" -i "./id" -v "./id" -o -v "./name" -b -n | grep -v ^$

Now I wanted to use the --var option and load the second XML by constructing the file path with the value of id and output the timestamp value, but I don't know how. Any idea?

Solution

  • Answer rewritten after question was rephrased.

    This should do it:

    # shellcheck  shell=sh  disable=SC2016
find '/home/a' -type f -iname '*.xml' -exec xmlstarlet select --text \
  -t -m 'root[string(id)]' \
       --var bpath='concat("/home/b/",id,".xml")' \
       --var ct='document($bpath)/root/counter1' \
       -v 'concat(id,",",name,",",$ct)' -n \
  {} +