The format command can produce a lot of warnings and errors when converting html documents to xml. This patch adds a quiet mode (-Q) which suppresses the error messages that get generated by libxml2. This makes it easier to use the xmlstarlet command in a pipeline without having to worry about messy stderr output.
Patch to xml_format.c 1.25 which adds --quiet mode
The patch has been applied with minor typos fixed in f7d1e62:
http://xmlstar.git.sourceforge.net/git/gitweb.cgi?p=xmlstar/xmlstar;a=commitdiff;h=f7d1e6253cdd9afcba14097fabab1914b878ba74