dpkg-trigger [option...] trigger-name dpkg-trigger [option...] command
dpkg-trigger is a tool to explicitly activate triggers and check for its support on the running dpkg.
This can be used by maintainer scripts in complex and conditional situations where the file triggers, or the declarative activate triggers control file directive, are insufficiently rich. It can also be used for testing and by system administrators (but note that the triggers won't actually be run by dpkg-trigger).
Unrecognized trigger name syntaxes are an error for dpkg-trigger.
dpkg(1), deb-triggers(5), /usr/share/doc/dpkg-dev/triggers.txt.gz.