From Koha Wiki
Here is a list of extra command-line utilities that are handy to have installed on your Koha server.
xmllint lets you test the validity and well-formedness of an XML file. Uses include:
- Making sure that you haven't introduced a syntax error when you've edited koha-conf.xml
- Checking the validity of a MARCXML file
How to get it:
- On Debian/Ubuntu: apt-get install libxml2-utils