A package declares its relationship to some trigger(s) by
including a triggers file in its control archive (i.e.
DEBIAN/triggers during package creation).
This file contains directives, one per line. Leading and trailing
whitespace and everything after the first # on any line will be
trimmed, and empty lines will be ignored.
The trigger control directives currently supported are:
interest trigger-name
interest-await trigger-name
interest-noawait trigger-name
Specifies that the package is interested in the named
trigger. All triggers in which a package is interested
must be listed using this directive in the triggers
control file.
The 'await' variants put the triggering package in
triggers-awaited state depending on how the trigger was
activated. The 'noawait' variant does not put the
triggering packages in triggers-awaited state, even if the
triggering package declared an 'await' activation (either
with an activate-await or activate directive, or by using
the dpkg-trigger --no-await command-line option). The
'noawait' variant should be used when the functionality
provided by the trigger is not crucial.
activate trigger-name
activate-await trigger-name
activate-noawait trigger-name
Arranges that changes to this package's state will
activate the specified trigger. The trigger will be
activated at the start of the following operations:
unpack, configure, remove (including for the benefit of a
conflicting package), purge and deconfigure.
The 'await' variants only put the triggering package in
triggers-awaited state if the interest directive is also
'await'. The 'noawait' variant never puts the triggering
packages in triggers-awaited state. The 'noawait' variant
should be used when the functionality provided by the
trigger is not crucial.
If this package disappears during the unpacking of another
package the trigger will be activated when the
disappearance is noted towards the end of the unpack.
Trigger processing, and transition from triggers-awaited
to installed, does not cause activations. In the case of
unpack, triggers mentioned in both the old and new
versions of the package will be activated.
Unknown directives are an error which will prevent installation
of the package.
The '-noawait' variants should always be favored when possible
since triggering packages are not put in triggers-awaited state
and can thus be immediately configured without requiring the
processing of the trigger. If the triggering packages are
dependencies of other upgraded packages, it will avoid an early
trigger processing run and make it possible to run the trigger
only once as one of the last steps of the upgrade.
The '-noawait' variants are supported since dpkg 1.16.1, and will
lead to errors if used with an older dpkg.
The '-await' alias variants are supported since dpkg 1.17.21, and
will lead to errors if used with an older dpkg.
When a package provides an interest-noawait directive, any
activation will set the triggering package into 'noawait' mode,
regardless of the awaiting mode requested by the activation
(either 'await' or 'noawait'). When a package provides an
interest or interest-await directive, any activation will set the
triggering package into 'await' or 'noawait' depending on how it
was activated.
