sd_bus_start(3) — Linux manual page


SD_BUS_START(3)               sd_bus_start               SD_BUS_START(3)

NAME         top

       sd_bus_start - Initiate a bus connection to the D-bus broker

SYNOPSIS         top

       #include <systemd/sd-bus.h>

       int sd_bus_start(sd_bus *bus);

DESCRIPTION         top

       sd_bus_start() connects an existing bus connection object to the
       D-Bus broker daemon, usually dbus-daemon(1) or dbus-broker(1).
       The mechanism to use for the connection must be configured before
       the call to sd_bus_start(), using one of sd_bus_set_address(3),
       sd_bus_set_fd(3), or sd_bus_set_exec(3).  sd_bus_start() will
       open the connection socket or spawn the executable as needed, and
       asynchronously start a org.freedesktop.DBus.Hello() call. The
       answer to the Hello call will be processed later from
       sd_bus_process(3). If opening of the connection or queuing of the
       asynchronous call fail, the connection will be closed with

       In most cases, it is better to use sd_bus_default_user(3),
       sd_bus_default_system(3) or related calls instead of the more
       low-level sd_bus_new() and sd_bus_start(). The higher-level
       functions not only allocate a bus object but also start the
       connection to a well-known bus in a single function call.

RETURN VALUE         top

       On success, this function returns a non-negative integer. On
       failure, it returns a negative errno-style error code.

           The input parameter bus is NULL.

           Added in version 246.

           Bus object bus could not be resolved.

           Added in version 246.

           The input parameter bus is in a wrong state (sd_bus_start()
           may only be called once on a newly-created bus object).

           Added in version 246.

           The bus object bus was created in a different process.

           Added in version 246.

       In addition, other connection-related errors may be returned. See

NOTES         top

       Functions described here are available as a shared library, which
       can be compiled against and linked to with the
       libsystemd pkg-config(1) file.

       The code described here uses getenv(3), which is declared to be
       not multi-thread-safe. This means that the code calling the
       functions described here must not call setenv(3) from a parallel
       thread. It is recommended to only do calls to setenv() from an
       early phase of the program when no other threads have been

HISTORY         top

       sd_bus_start() was added in version 246.

SEE ALSO         top

       systemd(1), sd-bus(3), sd_bus_default(3), sd_bus_call_async(3)

COLOPHON         top

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       This page was obtained from the project's upstream Git repository
       ⟨⟩ on 2024-06-14.  (At that
       time, the date of the most recent commit that was found in the
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       (which is not part of the original manual page), send a mail to

systemd 257~devel                                        SD_BUS_START(3)

Pages that refer to this page: sd-bus(3)sd_bus_default(3)sd_bus_is_open(3)sd_bus_negotiate_fds(3)sd_bus_new(3)sd_bus_set_address(3)sd_bus_set_fd(3)sd_bus_set_server(3)systemd.directives(7)systemd.index(7)