[SOLVED] Parsing XML attributes with bash

Parsing XML attributes with bash

I need to grab attributes from the XML file with pure bash script.

So I have the following XML file with a root element Group and lots of Person elements, every of them has id and username attributes. id is unique value for each element:

<?xml version="1.0" encoding="UTF-8"?>
<Group id="D_8"
       main="false">

    <Person id="P_0001"
            email="email0001@example.com"
            username="person_0001"
            password="pass_0001"
            active="true"/>

    <Person id="P_0002"
            email="email0002@example.com"
            username="person_0002"
            password="pass_0002"
            active="true"/>

    <!--  ...and hundreds of other Person elements ...  -->
</Group>

And I need to use bash script to extract the id and username attributes into some key-value structure:

P_0001=person_0001
P_0002=person_0002

Checked other related answers, but most of them suggest to use some XML parsers like xmllint. But unfortunately I do not have them on the target machine.

Please suggest how I can achieve this.

Solution

As long as the username attribute does not come before id attribute, this is a bash script to give the result:

#/usr/bin/env bash

id='\bid="([^"]+)"'
username='\busername="([^"]+)"'
while IFS= read -r line; do
    [[ $line =~ $id       ]] && idv="${BASH_REMATCH[1]}"
    [[ $line =~ $username ]] && echo "$idv=${BASH_REMATCH[1]}"
done < data.xml
exit 0

It works even when username attribute and id attribute are on the same line.