NAME

       dpkg-trigger - a package trigger utility

SYNOPSIS

       dpkg-trigger [option...] trigger-name

       dpkg-trigger [option...] command

DESCRIPTION

       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.

       This program was introduced in dpkg 1.14.17.

COMMANDS

       --check-supported
           Check if the running dpkg supports triggers (usually called from a postinst).  Will
           exit 0 if a triggers-capable dpkg has run, or 1 with an error message to stderr if
           not.  Normally, however, it is better just to activate the desired trigger with dpkg-
           trigger.

       -?, --help
           Show the usage message and exit.

       --version
           Show the version and exit.

OPTIONS

       --admindir=dir
           Change the location of the dpkg database.  Defaults to /var/lib/dpkg if DPKG_ADMINDIR
           has not been set.

       --root=directory
           Set the root directory to directory, which sets the administrative directory to
           «directory/var/lib/dpkg» (since dpkg 1.21.0).

       --by-package=package
           Override trigger awaiter (normally set by dpkg through the DPKG_MAINTSCRIPT_PACKAGE
           environment variable of the maintainer scripts, naming the package to which the script
           belongs, and this will be used by default).

       --no-await
           This option arranges that the calling package T (if any) need not await the processing
           of this trigger; the interested package(s) I, will not be added to T's trigger
           processing awaited list and T's status is unchanged.  T may be considered installed
           even though I may not yet have processed the trigger.

       --await
           This option does the inverse of --no-await (since dpkg 1.17.21).  If the interested
           package has declared a “noawait” directive, then this option will not be effective.
           It is currently the default behavior.

       --no-act
           Just test, do not actually change anything.

EXIT STATUS

       0   The requested action was successfully performed.  Or a check or assertion command
           returned true.

       1   A check or assertion command returned false.

       2   Fatal or unrecoverable error due to invalid command-line usage, or interactions with
           the system, such as accesses to the database, memory allocations, etc.

ENVIRONMENT

       DPKG_ROOT
           If set and the --root option has not been specified, it will be used as the filesystem
           root directory (since dpkg 1.21.0).

       DPKG_ADMINDIR
           If set and the --admindir option has not been specified, it will be used as the dpkg
           data directory.

       DPKG_DEBUG
           Sets the debug mask (since dpkg 1.21.10) from an octal value.  The currently accepted
           flags are described in the dpkg --debug option, but not all these flags might have an
           effect on this program.

       DPKG_COLORS
           Sets the color mode (since dpkg 1.18.5).  The currently accepted values are: auto
           (default), always and never.

SEE ALSO

       dpkg(1), deb-triggers(5), /usr/share/doc/dpkg/spec/triggers.txt.