NAME

       sd_bus_error_add_map, sd_bus_error_map, SD_BUS_ERROR_MAP, SD_BUS_ERROR_END - Additional
       sd-dbus error mappings

SYNOPSIS

       #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);

DESCRIPTION

       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.

RETURN VALUE

       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.

   Errors
       Returned errors may indicate the following problems:

       -EINVAL
           The specified mapping array is invalid.

       -ENOMEM
           Memory allocation failed.

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_error_add_map() was added in version 221.

SEE ALSO

       systemd(1), sd-bus(3), sd_bus_error(3), sd-bus-errors(3), errno(3), strerror_r(3)