$ Linux Command

Packages

dpkg-trigger

Activate dpkg triggers for deferred package operations.

debianpackagedpkgtriggeractivation

Additional Notes

dpkg-trigger manually activates a dpkg trigger from the command line. Triggers are a mechanism in Debian packaging that allows one package to cause another package to perform an action at a later time, typically during a dpkg run. This is used for operations that must happen after related packages are processed, such as rebuilding shared library caches or updating font indexes.

Normally triggers are activated automatically by dpkg when certain files are installed. However, dpkg-trigger can activate a trigger explicitly, which is useful during manual package operations, testing, or when a trigger needs to be fired outside of a normal dpkg transaction.

Syntax

dpkg-trigger [options] trigger-name

Parameters

  • trigger-name: The name of the trigger to activate (as declared in the package's control file).

Common Options

  • --by-package package: Specify the package name that is activating the trigger.
  • --no-await: Do not wait for the triggered processing to complete.
  • --await: Wait for the triggered processing to complete (default).
  • --check-supported: Check whether the running dpkg supports triggers.

Examples

dpkg-trigger --by-package myapp myapp-trigger

Activate the myapp-trigger trigger on behalf of myapp.

dpkg-trigger noawait ldconfig

Activate the ldconfig trigger without waiting for processing.

Practical Notes

  • Most users never need to invoke dpkg-trigger directly; it is primarily for package maintainers and debugging.
  • Common triggers include ldconfig (shared library cache), man-db (manual page index), and fontconfig (font cache).
  • The noawait variant (dpkg-trigger noawait trigger) allows parallel trigger processing.
  • To see which triggers a package supports, examine the DEBIAN/triggers file inside its .deb archive.
  • Triggers are processed at the end of a dpkg run, not immediately upon activation.