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notifyutil(1)             BSD General Commands Manual            notifyutil(1)


NAME

     notifyutil -- notification command line utility


SYNOPSIS

     notifyutil [-q] [-v] [-z msec] [-M] [-R] [command ...]


DESCRIPTION

     notifyutil is a command-line utility for interacting with the notify(3)
     notification system and the notifyd(8) server.  It may be used to post
     notifications, detect and report notifications, and to examine and set
     the state values associated with notification keys.

     If notifyutil is used to monitor one or more notification keys, it prints
     the notification key when the corresponding notification is received.
     The -v (verbose) and -q (quiet) flags, if specified, modify the output
     behavior.

     The -v flag causes notifyutil to print a time stamp, the notification
     key, the current state value for that key, and the type of the notifica-
     tion (port, file, etc).  The -q flag supresses any output except for
     state values fetched following a -g command.

     Commands listed in the table below are processed in left to right order
     from the command line.

           -p key       Post a notification for key.
           -w key       Register for key and wait forever for notifications.
           -# key       Register for key and wait for # (an integer) notifica-
                        tions.
                        E.g. -1 key waits for a single notification.
           -g key       Get state value for key.
           -s key val   Set state value for key.
           -port        Use mach port notifications for subsequent -w or -#
                        registrations.
                        This is the default registration type.
           -file        Use file descriptor notifications for subsequent reg-
                        istrations.
           -check       Use shared memory notifications for subsequent regis-
                        trations.
           -signal [#]  Use signal notifications for subsequent registrations.
                        Signal 1 (HUP) is the default, but an alternate signal
                        may be specified.
           -dispatch    Use dispatch for subsequent registrations.

     When invoked with any combination of -w and -# actions, notifyutil regis-
     ters for notification for the specified key(s).  If any key is given with
     a -w action, notifyutil runs until interrupted with Control-C.  If all
     registrations are invoked with -#, the program continues to run until the
     corresponding number of notifications for each key have been received.

     By default, notifyutil uses mach port registration (using
     notify_register_mach_port()) for keys given with a -w or -# flag.  The
     -file command causes notifyutil to use notify_register_file_descriptor()
     for any subsequent -w or -# registrations.  Similarly, -check causes
     notifyutil to use notify_register_check() for subsequent registrations,
     -signal switches to notify_register_signal(), and -dispatch causes it to
     use notify_register_dispatch() for subsequent registrations.

     If any registrations are made following the use of the -check command,
     notifyutil will start a timer and check for shared memory notifications
     every 100 milliseconds.  An alternate timer value may be set following
     the -z flag.

     The -M flag causes notifyutil to use multiplex all notifications over a
     single mach connection with notifyd.  Notifications (except shared memory
     notifications) are received and redistributed by a dispatch handler.

     The -R flag causes notifyutil to regenerate all its registrations in the
     unlikely event that notifyd restarts.

     Note that a notification key and its associated state variable only exist
     when there are one or more current registrations for that key.  Setting
     the state for a key that has no registrations has no effect.  Thus the
     command

           notifyutil -s foo.bar 123 -g foo.bar

     will print

           foo.bar 0

     unless foo.bar is registered by some other process.  However, the command

           notifyutil -w foo.bar -s foo.bar 123 -g foo.bar

     prints

           foo.bar 123

     since the ``-w foo.bar'' registration ensures the key and its state vari-
     able exist before the value is set, and continue to exist when the value
     is fetched.


SEE ALSO

     notify(3), notifyd(8)

Mac OS X                       November 4, 2011                       Mac OS X

Mac OS X 10.8 - Generated Wed Aug 22 15:49:45 CDT 2012
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