| SD_BUS_ERROR_ADD_MAP(3) | sd_bus_error_add_map | SD_BUS_ERROR_ADD_MAP(3) |
.SH "NAME" sd_bus_error_add_map, sd_bus_error_map,
SD_BUS_ERROR_MAP, SD_BUS_ERROR_END - Additional sd-dbus error mappings
.SH "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
.HP 600u int
sd_bus_error_add_map(const sd_bus_error_map *map);
.SH "DESCRIPTION"
.PP 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.
.PP 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.
.PP 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.
.PP 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.
.PP 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.
.SH "RETURN VALUE"
.PP 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.
.SS "Errors"
.PP Returned errors may indicate the following problems:
.PP -EINVAL
The specified mapping array is invalid.
.RE
.PP -ENOMEM
Memory allocation failed.
.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_error_add_map() was added in version 221.
.SH "SEE ALSO"
.PP systemd(1), sd-bus(3), sd_bus_error(3),
sd-bus-errors(3), errno(3), strerror_r(3)
| systemd 262.2 |