Error Handling

I am quite new to this XSLT processor as I have been using Sablotron for
quite some time.  I do have one question which I have been having quite a
hard time finding an answer to.  I am currently using version 1.1.12 of
libxslt and the latest version of libxml2 and compiling my apps in C with
gcc v2.95.2.  I am a little unclear on how to handle errors with the
processing of xml/xsl.  Currently all errors are being printed to stderr and
I would like to handle them on my own.  Does anyone have a snippet of code
that can show me how this is done?  I have searched the FAQ's and the list
with no luck.  Thank you.

- Anthony