NAME

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

SYNOPSIS

#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.

NOTES

These APIs are implemented as a shared library, which can be compiled and linked to with the libsystemd pkg-config(1) file.