установить или запросить адрес подключения к шине (Set or query the address of the bus connection)
Имя (Name)
sd_bus_set_address, sd_bus_get_address, sd_bus_set_exec - Set or
query the address of the bus connection
Синопсис (Synopsis)
#include <systemd/sd-bus.h>
int sd_bus_set_address(sd_bus *bus, const char *address);
int sd_bus_get_address(sd_bus *bus, const char **address);
int sd_bus_set_exec(sd_bus *bus, const char *path,
char *const *argv);
Описание (Description)
sd_bus_set_address() configures a list of addresses of bus
brokers to try to connect to from a subsequent sd_bus_start(3)
call. The argument is a ";"-separated list of addresses to try.
Each item must be one of the following:
• A unix socket address specified as "unix:guid=guid,path=path"
or "unix:guid=guid,abstract=path". Exactly one of the path=
and abstract= keys must be present, while guid= is optional.
• A TCP socket address specified as
"tcp:[guid=guid,][host=host][,port=port][,family=family]".
One or both of the host= and port= keys must be present,
while the rest is optional. family may be either ipv4 or
ipv6.
• An executable to spawn specified as
"unixexec:guid=guid,path=path,argv1=argument,argv2=argument,...".
The path= key must be present, while guid= is optional.
• A machine (container) to connect to specified as
"x-machine-unix:guid=guid,machine=machine,pid=pid". Exactly
one of the machine= and pid= keys must be present, while
guid= is optional. machine is the name of a local container.
See machinectl(1) for more information about the "machine"
concept. "machine=.host" may be used to specify the host
machine. A connection to the standard system bus socket
inside of the specified machine will be created.
In all cases, parameter guid is an identifier of the remote peer,
in the syntax accepted by sd_id128_from_string(3). If specified,
the identifier returned by the peer after the connection is
established will be checked and the connection will be rejected
in case of a mismatch.
Note that the addresses passed to sd_bus_set_address() may not be
verified immediately. If they are invalid, an error may be
returned e.g. from a subsequent call to sd_bus_start(3).
sd_bus_get_address() returns any previously set addresses. In
addition to being explicitly set by sd_bus_set_address(), the
address will also be set automatically by sd_bus_open(3) and
similar calls, based on environment variables or built-in
defaults.
sd_bus_set_exec() is a shorthand function for setting a
"unixexec" address that spawns the given executable with the
given arguments. If argv is NULL, the given executable is spawned
without any extra arguments.
Возвращаемое значение (Return value)
On success, these functions return a non-negative integer. On
failure, they return a negative errno-style error code.
Errors
Returned errors may indicate the following problems:
-EINVAL
The input parameters bus or address are NULL.
-ENOPKG
The bus object bus could not be resolved.
-EPERM
The input parameter bus is in a wrong state
(sd_bus_set_address() may only be called once on a
newly-created bus object).
-ECHILD
The bus object bus was created in a different process.
-ENODATA
The bus object bus has no address configured.
Примечание (Note)
These APIs are implemented as a shared library, which can be
compiled and linked to with the libsystemd pkg-config(1) file.
Смотри также (See also)
systemd(1), sd-bus(3), sd_bus_new(3), sd_bus_start(3),
systemd-machined.service(8), machinectl(1)
