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

SYNOPSIS

       #include <systemd/sd-bus.h>

       int sd_bus_message_set_destination(sd_bus_message *message, const char *destination);

       const char* sd_bus_message_get_destination(sd_bus_message *message);

       const char* sd_bus_message_get_path(sd_bus_message *message);

       const char* sd_bus_message_get_interface(sd_bus_message *message);

       const char* sd_bus_message_get_member(sd_bus_message *message);

       int sd_bus_message_set_sender(sd_bus_message *message, const char *sender);

       const char* sd_bus_message_get_sender(sd_bus_message *message);

DESCRIPTION

       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.

       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 is
       message is NULL or the message is of a type that doesn't use those fields or the message
       doesn't have them set. See sd_bus_message_new_method_call(3) and
       sd_bus_message_set_destination(3) for more discussion of those values.

       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.

       sd_bus_message_get_sender() returns the sender field from message.

       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 hasn't
       been changed by a different call.

RETURN VALUE

       On success, these calls return 0 or a positive integer. On failure, these calls return a
       negative errno-style error code.

   Errors
       Returned errors may indicate the following problems:

       -EINVAL
           The message parameter or the output parameter are NULL.

       -EPERM
           For sd_bus_message_set_destination() and sd_bus_message_set_sender(), the message is
           already sealed.

       -EEXIST
           The message already has a destination or sender field set.

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_message_set_destination() and sd_bus_message_set_sender() were added in version
       237.

       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.

SEE ALSO

       systemd(1), sd-bus(3), sd_bus_new(3), sd_bus_set_sender(3)