# sd_bus_message_set_destination

## 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 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.
    
           **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 has not 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.
    


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