NAME

       sd_bus_set_property, sd_bus_set_propertyv, sd_bus_get_property,
       sd_bus_get_property_trivial, sd_bus_get_property_string, sd_bus_get_property_strv - Set or
       query D-Bus service properties

SYNOPSIS

       #include <systemd/sd-bus.h>

       int sd_bus_set_property(sd_bus *bus, const char *destination, const char *path,
                               const char *interface, const char *member,
                               sd_bus_error *ret_error, const char *type, ...);

       int sd_bus_set_propertyv(sd_bus *bus, const char *destination, const char *path,
                                const char *interface, const char *member,
                                sd_bus_error *ret_error, const char *type, va_list ap);

       int sd_bus_get_property(sd_bus *bus, const char *destination, const char *path,
                               const char *interface, const char *member,
                               sd_bus_error *ret_error, sd_bus_message **reply,
                               const char *type);

       int sd_bus_get_property_trivial(sd_bus *bus, const char *destination, const char *path,
                                       const char *interface, const char *member,
                                       sd_bus_error *ret_error, char type, void *ret_ptr);

       int sd_bus_get_property_string(sd_bus *bus, const char *destination, const char *path,
                                      const char *interface, const char *member,
                                      sd_bus_error *ret_error, char **ret);

       int sd_bus_get_property_strv(sd_bus *bus, const char *destination, const char *path,
                                    const char *interface, const char *member,
                                    sd_bus_error *ret_error, char ***ret);

DESCRIPTION

       These functions set or query D-Bus properties. D-Bus properties are service fields exposed
       via the org.freedesktop.DBus.Properties interface. Under the hood, these functions call
       methods of the org.freedesktop.DBus.Properties interface and as a result their semantics
       are similar to sd_bus_call_method(3).

       sd_bus_set_property() sets a D-Bus property. If setting the property fails or an internal
       error occurs, an error is returned and an extended description of the error is optionally
       stored in ret_error if it is not NULL.  type and the arguments that follow it describe the
       new value of the property and must follow the format described in
       sd_bus_message_append(3).

       sd_bus_set_propertyv() is equivalent to sd_bus_set_property(), except that it is called
       with a "va_list" instead of a variable number of arguments.

       sd_bus_get_property() queries a D-Bus property. If retrieving the property fails or an
       internal error occurs, an error is returned and an extended description of the error is
       optionally stored in ret_error if it is not NULL. On success, the property is stored in
       reply.  type describes the property type and must follow the format described in
       sd_bus_message_append(3).

       sd_bus_get_property_trivial(), sd_bus_get_property_string() and sd_bus_get_property_strv()
       are shorthands for sd_bus_get_property() that are used to query basic, string and string
       vector properties respectively. The caller is responsible for freeing the string and
       string vector results stored in ret by sd_bus_get_property_string() and
       sd_bus_get_property_strv().

RETURN VALUE

       On success, these functions return a non-negative integer. On failure, they return a
       negative errno-style error code.

   Errors
       See the sd_bus_call_method(3) man page for a list of possible errors.

NOTES

       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 started.

HISTORY

       sd_bus_set_property(), sd_bus_set_propertyv(), sd_bus_get_property(),
       sd_bus_get_property_trivial(), sd_bus_get_property_string(), and
       sd_bus_get_property_strv() were added in version 246.

SEE ALSO

       systemd(1), sd-bus(3), sd_bus_call_method(3)