glib/docs/reference/gio/gdbus.xml
Philip Withnall 7890573f6e gdbus-tool: Add a command to wait for a well-known name on the bus
This is effectively the mc-wait-for-name tool from
telepathy-mission-control; moving it in to gdbus-tool will make it more
widely useful without making people depend on telepathy-mission-control
for no other reason. The code here is reimplemented from scratch to use
GDBus.

It blocks until the specified well-known name is owned by some process
on the bus (which can be the session, system, or any other bus). By
passing --activate, the same (or a different) name can be auto-started
on the bus first.

A timeout can be specified to ensure the process doesn’t block forever.

https://bugzilla.gnome.org/show_bug.cgi?id=745971
2017-03-28 11:23:27 +01:00

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<refentry id="gdbus" lang="en">
<refentryinfo>
<title>gdbus</title>
<productname>GIO</productname>
<authorgroup>
<author>
<contrib>Developer</contrib>
<firstname>David</firstname>
<surname>Zeuthen</surname>
<email>zeuthen@gmail.com</email>
</author>
</authorgroup>
</refentryinfo>
<refmeta>
<refentrytitle>gdbus</refentrytitle>
<manvolnum>1</manvolnum>
<refmiscinfo class="manual">User Commands</refmiscinfo>
</refmeta>
<refnamediv>
<refname>gdbus</refname>
<refpurpose>Tool for working with D-Bus objects</refpurpose>
</refnamediv>
<refsynopsisdiv>
<cmdsynopsis>
<command>gdbus</command>
<arg choice="plain">introspect</arg>
<group>
<arg choice="plain">--system</arg>
<arg choice="plain">--session</arg>
<arg choice="plain">--address <replaceable>address</replaceable></arg>
</group>
<arg choice="plain">--dest <replaceable>bus_name</replaceable></arg>
<arg choice="plain">--object-path <replaceable>/path/to/object</replaceable></arg>
<group>
<arg choice="plain">--xml</arg>
</group>
<group>
<arg choice="plain">--recurse</arg>
</group>
<group>
<arg choice="plain">--only-properties</arg>
</group>
</cmdsynopsis>
<cmdsynopsis>
<command>gdbus</command>
<arg choice="plain">monitor</arg>
<group>
<arg choice="plain">--system</arg>
<arg choice="plain">--session</arg>
<arg choice="plain">--address <replaceable>address</replaceable></arg>
</group>
<arg choice="plain">--dest <replaceable>bus_name</replaceable></arg>
<group>
<arg choice="plain">--object-path <replaceable>/path/to/object</replaceable></arg>
</group>
</cmdsynopsis>
<cmdsynopsis>
<command>gdbus</command>
<arg choice="plain">call</arg>
<group>
<arg choice="plain">--system</arg>
<arg choice="plain">--session</arg>
<arg choice="plain">--address <replaceable>address</replaceable></arg>
</group>
<arg choice="plain">--dest <replaceable>bus_name</replaceable></arg>
<arg choice="plain">--object-path <replaceable>/path/to/object</replaceable></arg>
<arg choice="plain">--method <replaceable>org.project.InterfaceName.MethodName</replaceable></arg>
<group>
<arg choice="plain">--timeout <replaceable>seconds</replaceable></arg>
</group>
<arg choice="plain">ARG1</arg>
<arg choice="plain" rep="repeat">ARG2</arg>
</cmdsynopsis>
<cmdsynopsis>
<command>gdbus</command>
<arg choice="plain">emit</arg>
<group>
<arg choice="plain">--system</arg>
<arg choice="plain">--session</arg>
<arg choice="plain">--address <replaceable>address</replaceable></arg>
</group>
<arg choice="plain">--object-path <replaceable>/path/to/object</replaceable></arg>
<arg choice="plain">--signal <replaceable>org.project.InterfaceName.SignalName</replaceable></arg>
<group>
<arg choice="plain">--dest <replaceable>unique_bus_name</replaceable></arg>
</group>
<arg choice="plain">ARG1</arg>
<arg choice="plain" rep="repeat">ARG2</arg>
</cmdsynopsis>
<cmdsynopsis>
<command>gdbus</command>
<arg choice="plain">wait</arg>
<group>
<arg choice="plain">--system</arg>
<arg choice="plain">--session</arg>
<arg choice="plain">--address <replaceable>address</replaceable></arg>
</group>
<arg choice="plain">--activate <replaceable>bus_name</replaceable></arg>
<group>
<arg choice="plain">--timeout <replaceable>seconds</replaceable></arg>
</group>
<arg choice="plain"><replaceable>bus_name</replaceable></arg>
</cmdsynopsis>
<cmdsynopsis>
<command>gdbus</command>
<arg choice="plain">help</arg>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para>
<command>gdbus</command> is a simple tool for working with D-Bus objects.
</para>
</refsect1>
<refsect1>
<title>Commands</title>
<variablelist>
<varlistentry>
<term><option>introspect</option></term>
<listitem><para>
Prints out interfaces and property values for a remote object.
For this to work, the owner of the object needs to implement the
<literal>org.freedesktop.DBus.Introspectable</literal> interface.
If the <option>--xml</option> option is used, the returned
introspection XML is printed, otherwise a parsed pretty
representation is printed.
The <option>--recurse</option> option can be used to
introspect children (and their children and so on) and the
<option>--only-properties</option> option can be used to
only print the interfaces with properties.
</para></listitem>
</varlistentry>
<varlistentry>
<term><option>monitor</option></term>
<listitem><para>
Monitors one or all objects owned by the owner of
<replaceable>bus_name</replaceable>.
</para></listitem>
</varlistentry>
<varlistentry>
<term><option>call</option></term>
<listitem><para>
Invokes a method on a remote object. Each argument to pass to the
method must be specified as a serialized
<link linkend="GVariant"><type>GVariant</type></link> except that strings do
not need explicit quotes. The return values are printed out as
serialized <link linkend="GVariant"><type>GVariant</type></link>
values.
</para></listitem>
</varlistentry>
<varlistentry>
<term><option>emit</option></term>
<listitem><para>
Emits a signal. Each argument to include in the signal must be specified as a serialized
<link linkend="GVariant"><type>GVariant</type></link> except that strings do
not need explicit quotes.
</para></listitem>
</varlistentry>
<varlistentry>
<term><option>wait</option></term>
<listitem><para>
Waits until <replaceable>bus_name</replaceable> is owned by some
process on the bus. If the <option>--activate</option> is specified,
that bus name will be auto-started first. It may be the same as the
bus name being waited for, or different.
</para></listitem>
</varlistentry>
<varlistentry>
<term><option>help</option></term>
<listitem><para>
Prints help and exit.
</para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Bash Completion</title>
<para>
<command>gdbus</command> ships with a bash completion script to
complete commands, destinations, bus names, object paths and
interface/method names.
</para>
</refsect1>
<refsect1>
<title>Examples</title>
This shows how to introspect an object - note that the value of each
property is displayed:
<programlisting>
$ gdbus introspect --system \
--dest org.freedesktop.NetworkManager \
--object-path /org/freedesktop/NetworkManager/Devices/0
node /org/freedesktop/NetworkManager/Devices/0 {
interface org.freedesktop.DBus.Introspectable {
methods:
Introspect(out s data);
};
interface org.freedesktop.DBus.Properties {
methods:
Get(in s interface,
in s propname,
out v value);
Set(in s interface,
in s propname,
in v value);
GetAll(in s interface,
out a{sv} props);
};
interface org.freedesktop.NetworkManager.Device.Wired {
signals:
PropertiesChanged(a{sv} arg_0);
properties:
readonly b Carrier = false;
readonly u Speed = 0;
readonly s HwAddress = '00:1D:72:88:BE:97';
};
interface org.freedesktop.NetworkManager.Device {
methods:
Disconnect();
signals:
StateChanged(u arg_0,
u arg_1,
u arg_2);
properties:
readonly u DeviceType = 1;
readonly b Managed = true;
readwrite o Ip6Config = '/';
readwrite o Dhcp4Config = '/';
readwrite o Ip4Config = '/';
readonly u State = 2;
readwrite u Ip4Address = 0;
readonly u Capabilities = 3;
readonly s Driver = 'e1000e';
readwrite s Interface = 'eth0';
readonly s Udi = '/sys/devices/pci0000:00/0000:00:19.0/net/eth0';
};
};
</programlisting>
<para>
The <option>--recurse</option> and <option>--only-properties</option> options can be useful when wanting to inspect all objects owned by a particular process:
</para>
<programlisting>
$ gdbus introspect --system --dest org.freedesktop.UPower --object-path / --recurse --only-properties
node / {
node /org {
node /org/freedesktop {
node /org/freedesktop/UPower {
interface org.freedesktop.UPower {
properties:
readonly b IsDocked = true;
readonly b LidForceSleep = false;
readonly b LidIsPresent = false;
readonly b LidIsClosed = false;
readonly b OnLowBattery = false;
readonly b OnBattery = false;
readonly b CanHibernate = true;
readonly b CanSuspend = true;
readonly s DaemonVersion = '0.9.10';
};
node /org/freedesktop/UPower/Policy {
};
node /org/freedesktop/UPower/Wakeups {
interface org.freedesktop.UPower.Wakeups {
properties:
readonly b HasCapability = true;
};
};
};
};
};
};
</programlisting>
<para>
In a similar fashion, the <option>introspect</option> command can be
used to learn details about the <literal>Notify</literal> method:
</para>
<programlisting>
[...]
interface org.freedesktop.Notifications {
methods:
GetServerInformation(out s return_name,
out s return_vendor,
out s return_version,
out s return_spec_version);
GetCapabilities(out as return_caps);
CloseNotification(in u id);
Notify(in s app_name,
in u id,
in s icon,
in s summary,
in s body,
in as actions,
in a{sv} hints,
in i timeout,
out u return_id);
};
[...]
</programlisting>
<para>
With this information, it's easy to use the <option>call</option>
command to display a notification
</para>
<programlisting>
$ gdbus call --session \
--dest org.freedesktop.Notifications \
--object-path /org/freedesktop/Notifications \
--method org.freedesktop.Notifications.Notify \
my_app_name \
42 \
gtk-dialog-info \
"The Summary" \
"Here's the body of the notification" \
[] \
{} \
5000
(uint32 12,)
</programlisting>
<para>
Monitoring all objects on a service:
</para>
<programlisting>
$ gdbus monitor --system --dest org.freedesktop.ConsoleKit
Monitoring signals from all objects owned by org.freedesktop.ConsoleKit
The name org.freedesktop.ConsoleKit is owned by :1.15
/org/freedesktop/ConsoleKit/Session2: org.freedesktop.ConsoleKit.Session.ActiveChanged (false,)
/org/freedesktop/ConsoleKit/Seat1: org.freedesktop.ConsoleKit.Seat.ActiveSessionChanged ('',)
/org/freedesktop/ConsoleKit/Session2: org.freedesktop.ConsoleKit.Session.ActiveChanged (true,)
/org/freedesktop/ConsoleKit/Seat1: org.freedesktop.ConsoleKit.Seat.ActiveSessionChanged ('/org/freedesktop/ConsoleKit/Session2',)
</programlisting>
<para>
Monitoring a single object on a service:
</para>
<programlisting>
$ gdbus monitor --system --dest org.freedesktop.NetworkManager --object-path /org/freedesktop/NetworkManager/AccessPoint/4141
Monitoring signals on object /org/freedesktop/NetworkManager/AccessPoint/4141 owned by org.freedesktop.NetworkManager
The name org.freedesktop.NetworkManager is owned by :1.5
/org/freedesktop/NetworkManager/AccessPoint/4141: org.freedesktop.NetworkManager.AccessPoint.PropertiesChanged ({'Strength': &lt;byte 0x5c&gt;},)
/org/freedesktop/NetworkManager/AccessPoint/4141: org.freedesktop.NetworkManager.AccessPoint.PropertiesChanged ({'Strength': &lt;byte 0x64&gt;},)
/org/freedesktop/NetworkManager/AccessPoint/4141: org.freedesktop.NetworkManager.AccessPoint.PropertiesChanged ({'Strength': &lt;byte 0x5e&gt;},)
/org/freedesktop/NetworkManager/AccessPoint/4141: org.freedesktop.NetworkManager.AccessPoint.PropertiesChanged ({'Strength': &lt;byte 0x64&gt;},)
</programlisting>
<para>
Emitting a signal:
</para>
<programlisting>
$ gdbus emit --session --object-path /foo --signal org.bar.Foo "['foo', 'bar', 'baz']"
</programlisting>
<para>
Emitting a signal to a specific process:
</para>
<programlisting>
$ gdbus emit --session --object-path /bar --signal org.bar.Bar someString --dest :1.42
</programlisting>
<para>
Waiting for a well-known name to be owned on the bus; this will
<emphasis>not</emphasis> auto-start the service:
</para>
<programlisting>
$ gdbus wait --session org.bar.SomeName
</programlisting>
<para>
Auto-starting then waiting for a well-known name to be owned on the bus:
</para>
<programlisting>
$ gdbus wait --session --activate org.bar.SomeName
</programlisting>
<para>
Auto-starting a different service, then waiting for a well-known name to be
owned on the bus. This is useful in situations where
<replaceable>SomeName</replaceable> is not directly activatable:
</para>
<programlisting>
$ gdbus wait --session --activate org.bar.PrerequisiteName org.bar.SomeName
</programlisting>
<para>
Waiting for a well-known name and giving up after 30 seconds. By default,
the timeout is disabled; or set <option>--timeout</option> to 0 to disable it:
</para>
<programlisting>
$ gdbus wait --session --timeout 30 org.bar.SomeName
</programlisting>
</refsect1>
<refsect1>
<title>Bugs</title>
<para>
Please send bug reports to either the distribution bug tracker
or the upstream bug tracker at
<ulink url="https://bugzilla.gnome.org/enter_bug.cgi?product=glib"/>.
</para>
</refsect1>
<refsect1>
<title>See Also</title>
<para>
<citerefentry>
<refentrytitle>dbus-send</refentrytitle><manvolnum>1</manvolnum>
</citerefentry>
</para>
</refsect1>
</refentry>