validate xml against xsd

[David Wright <ichbin@shadlen.org>]

I am looking for a simple command-line utility that allows me to 
validate a given xml file against a given xsd file. For example:

$ validate test.xml test.xsd
Error on line 41: <foobar> element missing

For this project, I don't need a programming library that gives me a DOM 
or SAX view of the file. I just need pure command-line driven 
validation. Does such a utility exist, either as a Debian package or out 
there as source code?