sd_hwdb_new

systemd

sd_hwdb_new

sd_hwdb_new_from_path

sd_hwdb_ref

sd_hwdb_unref

Create a new hwdb object and create or destroy references to it

#include <systemd/sd-hwdb.h>

int

sd_hwdb_new

sd_hwdb **

hwdb

int

sd_hwdb_new_from_path

const char *

path

sd_hwdb **

hwdb

sd_hwdb*

sd_hwdb_ref

sd_hwdb *

hwdb

sd_hwdb*

sd_hwdb_unref

sd_hwdb *

hwdb

Description

sd_hwdb_new() creates a new hwdb object to access the binary hwdb database. Upon initialization, the file containing the binary representation of the hardware database is located and opened. The new object is returned in hwdb.

sd_hwdb_new_from_path() may be used to specify the path from which the binary hardware database should be opened.

The hwdb object is reference counted. sd_hwdb_ref() and sd_hwdb_unref() may be used to get a new reference or destroy an existing reference to an object. The caller must dispose of the reference acquired with sd_hwdb_new() by calling sd_hwdb_unref() when done with the object.

Use sd_hwdb_seek(3), sd_hwdb_get(3), and sd_hwdb_enumerate(3) to access entries.

Return Value

On success, sd_hwdb_new() and sd_hwdb_new_from_path() return a non-negative integer. On failure, a negative errno-style error code is returned.

sd_hwdb_ref() always returns the argument.

sd_hwdb_unref() always returns NULL.

Errors

Returned errors may indicate the following problems:

-ENOENT
The binary hardware database file could not be located. See systemd-hwdb(8) for more information.

-EINVAL
The located binary hardware database file is in an incompatible format.

-ENOMEM
Memory allocation failed.

History

sd_hwdb_new(), sd_hwdb_ref(), and sd_hwdb_unref() were added in version 246.

sd_hwdb_new_from_path() was added in version 252.