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 notifi-
cation (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) notifications.
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 registrations.
-check Use shared memory notifications for subsequent registrations.
-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 registers 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 com-
mand 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 notifica-
tions 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 variable 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