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.Dd July 11, 2010
.Dt UDEV 3
.Os
.Sh NAME
.Nm udev_new ,
.Nm udev_ref ,
.Nm udev_unref ,
.Nm udev_get_dev_path ,
.Nm udev_set_userdata ,
.Nm udev_get_userdata
.Nd general udev functions
.Sh LIBRARY
.Lb libdevattr
.Sh SYNOPSIS
.In devattr.h
.Ft struct udev *
.Fn udev_new "void"
.Ft struct udev *
.Fn udev_ref "struct udev *udev_ctx"
.Ft void
.Fn udev_unref "struct udev *udev_ctx"
.Ft const char *
.Fn udev_get_dev_path "struct udev *udev_ctx"
.Ft void
.Fn udev_set_userdata "struct udev *udev_ctx" "void *userdata"
.Ft void *
.Fn udev_get_userdata "struct udev *udev_ctx"
.Sh DESCRIPTION
The
.Fn udev_new
function returns a new udev context.
This is needed as a context for all other libdevattr functions.
The returned context has a refcount of 1.
This function returns
.Dv NULL
if no udev context could be created, which usually happens when
the udevd daemon is not running.
.Pp
The
.Fn udev_ref
and
.Fn udev_unref
functions increase or decrease the reference count on a udev object respectively.
When the reference count drops to 0, the object is automatically destroyed.
The
.Fn udev_ref
function returns the same object that was passed in.
.Pp
The
.Fn udev_get_dev_path
function returns the path to the system device directory.
.Pp
The
.Fn udev_set_userdata
function allows the consumer to associate some
.Fa userdata
to the specified
.Fa udev_ctx .
The
.Fn udev_get_userdata
function returns the currently associated user data.
.Sh SEE ALSO
.Xr devattr 3 ,
.Xr udev_device 3 ,
.Xr udev_enumerate 3 ,
.Xr udev_monitor 3 ,
.Xr udevd 8