notifyutil(1) | General Commands Manual | notifyutil(1) |
notifyutil
—
notification command line utility
notifyutil |
[-q ] [-v ]
[-z msec]
[-M ] [-R ] [command
... ] |
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 notification
(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-w
key-
#
keyE.g.
-1
key waits for a single
notification.-g
key-s
key val-port
-w
or
-
# registrations.-file
-check
-signal
[#]-dispatch
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
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 variable exist before the value is set, and continue to exist when the value is fetched.
notify(3), notifyd(8)
November 4, 2011 | Mac OS X |