# dpkg manual page - deb-triggers(5)
#
# Copyright © 2008, 2013-2015 Guillem Jover <guillem@debian.org>
# Copyright © 2011, 2014 Raphaël Hertzog <hertzog@debian.org>
#
# This is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
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#
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=encoding utf8

=head1 NAME

deb-triggers - package triggers

=head1 SYNOPSIS

B<debian/triggers>, B<debian/>I<binary-package>B<.triggers>,
B<DEBIAN/triggers>

=head1 DESCRIPTION

A package declares its relationship to some trigger(s) by including
a I<triggers> file in its control archive (i.e. I<DEBIAN/triggers>
during package creation).

This file contains directives, one per line.
Leading and trailing whitespace
and everything after the first B<#> on any line will be trimmed, and
empty lines will be ignored.

The trigger control directives currently supported are:

=over

=item B<interest> I<trigger-name>

=item B<interest-await> I<trigger-name>

=item B<interest-noawait> I<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 B<activate-await> or B<activate>
directive, or by using the B<dpkg-trigger> B<--no-await>
command-line option).
The “noawait” variant should be used when the functionality provided
by the trigger is not crucial.

=item B<activate> I<trigger-name>

=item B<activate-await> I<trigger-name>

=item B<activate-noawait> I<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.

=back

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 B<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 B<interest> or B<interest-await> directive,
any activation will set the triggering package into “await” or “noawait“
depending on how it was activated.

=head1 SEE ALSO

L<dpkg-trigger(1)>,
L<dpkg(1)>,
B<%PKGDOCDIR%/spec/triggers.txt>.
