The HUD service is available as a service on DBus, so if you'd just like to poll it for information you can do that with a gdbus command, like this.
gdbus call --session --dest com.canonical.hud --object-path /com/canonical/hud --method com.canonical.hud.StartQuery "my query" 5
If you're trying to get Unity to show the HUD prompt you can do that with the XTest extension using xdotool like this:
xdotool key alt
If you're interested in playing with HUD it's probably best to use the hud-gtk tool which is in the indicator-appmenu-tools package.
5at the end of your code do? – nanofarad May 16 '12 at 11:50('', @a(sssssv) [], <'query key'>)Am I missing part of the command, or does part of the command need to be modified in order to work correctly? – Anderson Green Nov 13 '12 at 17:50