Validating Midnams with something other than xmllint

#1

xmllint will not validate when the dtd is from an https source.

Is there a newer way to validate xml ?

#2

Per the author’s comments in the Gitlab issue, the preferred mode is to install the external DTDs into your local XML catalog, which lives in /etc/xml on a Linux machine. The trick here is to thing of the string http://www.midi.org/dtds/MIDINameDocument10.dtd as a URI (a globally-unique identifier) for the DTD, rather than its URL (the place where you happen to be able to fetch the DTD as a file).

I just tried the following:

$ sudo cp /etc/xml/catalog{,-ASIDE}  # save backup copy
$ sudo mkdir /etc/xml/midi  #  put MIDI-related catalog entries here
$ sudo wget -nv -O /etc/xml/midi/MIDINameDocument10.dtd http://www.midi.org/dtds/MIDINameDocument10.dtd
2024-01-10 02:22:32 URL:https://midi.org/dtds/MIDINameDocument10.dtd [4498/4498] -> "/etc/xml/midi/MIDINameDocument10.dtd" [1]
$ sudo xmlcatalog --noout --add system http://www.midi.org/dtds/MIDINameDocument10.dtd midi/MIDINameDocument10.dtd /etc/xml/catalog
$ grep MIDI /etc/xml/catalog
  <system systemId="http://www.midi.org/dtds/MIDINameDocument10.dtd" uri="midi/MIDINameDocument10.dtd"/>

Next, I tried to validate one of the midnam files shipped by Ardour:

$ xmllint --noout --valid /opt/Ardour-8.2.0/share/patchfiles/MIDI.midnam && echo YES || echo NO
error : Unknown IO error
file:///etc/xml/midi/MIDINameDocument10.dtd:154: warning: failed to load external entity "http://www.midi.org/dtds/MIDIEvents10.dtd"
...

So, we need to download and install another DTD, this one for MIDI events:

$ sudo wget -nv -O /etc/xml/midi/MIDIEvents10.dtd https://midi.org/dtds/MIDIEvents10.dtd
2024-01-10 02:25:51 URL:https://midi.org/dtds/MIDIEvents10.dtd [6363/6363] -> "/etc/xml/midi/MIDIEvents10.dtd" [1]
$ sudo xmlcatalog --noout --add system http://www.midi.org/dtds/MIDIEvents10.dtd midi/MIDIEvents10.dtd /etc/xml/catalog
$ grep MIDI /etc/xml/catalog
  <system systemId="http://www.midi.org/dtds/MIDINameDocument10.dtd" uri="midi/MIDINameDocument10.dtd"/>
  <system systemId="http://www.midi.org/dtds/MIDIEvents10.dtd" uri="midi/MIDIEvents10.dtd"/>

And try the validation again:

$ xmllint --noout --valid /opt/Ardour-8.2.0/share/patchfiles/MIDI.midnam && echo YES || echo NO
YES
3 Likes
#3

Nice walkthough. Thanks

The two document type definition files are included with Ardour’s source in share/patchfiles/ (but not installed), so it’s easier to validate if you have the source code around.

#4

Thank you for this! It worked!

#5

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