sd_bus_error_add_map, sd_bus_error_map, SD_BUS_ERROR_MAP, SD_BUS_ERROR_END — Additional sd-dbus error mappings
#include <systemd/sd-bus.h>
typedef struct { const char *name; int code; … } sd_bus_error_map;
SD_BUS_ERROR_MAP(name
, code
)
SD_BUS_ERROR_MAP_END
int sd_bus_error_add_map( | const sd_bus_error_map *map) ; |
The sd_bus_error_add_map()
call may be
used to register additional mappings for converting D-Bus errors
to Linux errno
-style errors. The mappings
defined with this call are consulted by calls such as
sd_bus_error_set(3)
or
sd_bus_error_get_errno(3). By
default, a number of generic, standardized mappings are known, as
documented in
sd-bus-errors(3). Use
this call to add further, application-specific mappings.
The function takes a pointer to an array of sd_bus_error_map structures. A reference to the specified array is added to the lookup tables for error mappings. Note that the structure is not copied, and that it is hence essential that the array stays available and constant during the entire remaining runtime of the process.
The mapping array should be put together with a series of
SD_BUS_ERROR_MAP()
macro invocations that
take a literal name string and a (positive)
errno
-style error number. The last entry of the
array should be an invocation of the
SD_BUS_ERROR_MAP_END
macro. The array should not be
put together without use of these two macros.
Note that the call is idempotent: it is safe to invoke it multiple times with the parameter, which will only add the passed mapping array once.
Note that the memory allocated by this call is not intended to be freed during the lifetime of the process. It should not be freed explicitly.
sd_bus_error_add_map()
returns a
positive value when the new array was added to the lookup
tables. It returns zero when the same array was already added
before. On error, a negative errno
-style error
code is returned. See below for known error codes.
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.