| SD_BUS_MESSAGE_SET_DESTINATION(3) | sd_bus_message_set_destination | SD_BUS_MESSAGE_SET_DESTINATION(3) |
.SH "NAME" sd_bus_message_set_destination,
sd_bus_message_get_destination, sd_bus_message_get_path,
sd_bus_message_get_interface, sd_bus_message_get_member,
sd_bus_message_set_sender, sd_bus_message_get_sender - Set and query bus
message addressing information
.SH "SYNOPSIS"
#include <systemd/sd-bus.h>
.HP 840u int
sd_bus_message_set_destination(sd_bus_message *message,
const char *destination);
.HP 1032u const char*
sd_bus_message_get_destination(sd_bus_message *message);
.HP 864u const char*
sd_bus_message_get_path(sd_bus_message *message);
.HP 984u const char*
sd_bus_message_get_interface(sd_bus_message *message);
.HP 912u const char*
sd_bus_message_get_member(sd_bus_message *message);
.HP 720u int
sd_bus_message_set_sender(sd_bus_message *message,
const char *sender);
.HP 912u const char*
sd_bus_message_get_sender(sd_bus_message *message);
.SH "DESCRIPTION"
.PP sd_bus_message_set_destination() sets the destination service name
for the specified bus message object. The specified name must be a valid
unique or well-known service name.
.PP sd_bus_message_get_destination(),
sd_bus_message_get_path(), sd_bus_message_get_interface(), and
sd_bus_message_get_member() return the destination, path, interface,
and member fields from message header. The return value will be
NULL if message is NULL or the message is of a type
that does not use those fields or the message does not have them set. See
sd_bus_message_new_method_call(3) and
sd_bus_message_set_destination(3) for more discussion of those
values.
.PP sd_bus_message_set_sender() sets the sender service name for the
specified bus message object. The specified name must be a valid unique or
well-known service name. This function is useful only for messages to send
on direct connections as for connections to bus brokers the broker will fill
in the destination field anyway, and the sender field set by original sender
is ignored.
.PP sd_bus_message_get_sender() returns the sender field from
message.
.PP When a string is returned, it is a pointer to internal storage, and may
not be modified or freed. It is only valid as long as the message
remains referenced and this field has not been changed by a different
call.
.SH "RETURN VALUE"
.PP On success, these calls return 0 or a positive integer. On failure, these
calls return a negative errno-style error code.
.SS "Errors"
.PP Returned errors may indicate the following problems:
.PP -EINVAL
The message parameter or the output parameter are NULL.
.RE
.PP -EPERM
For sd_bus_message_set_destination() and
sd_bus_message_set_sender(), the message is already sealed.
.RE
.PP -EEXIST
The message already has a destination or sender field set.
.RE
.SH "NOTES"
.PP Functions described here are available as a shared library, which can be
compiled against and linked to with the
libsystemd pkg-config(1) file.
.PP All functions listed here are thread-agnostic and only a single thread
may operate on a given object at any given time. Different threads may
access the same object at different times. Multiple independent objects may
be used from different threads in parallel.
.PP 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.
.SH "HISTORY"
.PP sd_bus_message_set_destination() and
sd_bus_message_set_sender() were added in version 237.
.PP sd_bus_message_get_destination(),
sd_bus_message_get_path(), sd_bus_message_get_interface(),
sd_bus_message_get_member(), and sd_bus_message_get_sender()
were added in version 240.
.SH "SEE ALSO"
.PP systemd(1), sd-bus(3), sd_bus_new(3),
sd_bus_set_sender(3)
| systemd 262.2 |