xmllint : how to validate an XML using a local DTD file
First of all, external DTDs do not need the <!DOCTYPE preamble - remove it from the DTD file:
<!ELEMENT coord (date)><!ELEMENT date (#PCDATA)>Then, --loaddtd fetches an external DTD, which is not the same as validating against an external DTD. Use the --dtdvalid option as follows:
$ xmllint --noout --dtdvalid test.dtd test.xmlIf the XML document is valid, xmllint will not output anything (because of --noout). If you change the DTD to, say:
<!ELEMENT coord (date,other)><!ELEMENT date (#PCDATA)>The output will be
$ xmllint --noout --dtdvalid test.dtd test.xmltest.xml:2: element coord: validity error : Element coord content does not follow the DTD, expecting (date , other), got (date )Document test.xml does not validate against test.dtdLook for more information on the doc pages of NMT or XMLSoft.