1.\" 2.\" Copyright (c) 2010 The DragonFly Project. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in 12.\" the documentation and/or other materials provided with the 13.\" distribution. 14.\" 3. Neither the name of The DragonFly Project nor the names of its 15.\" contributors may be used to endorse or promote products derived 16.\" from this software without specific, prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20.\" LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 21.\" FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 22.\" COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 23.\" INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 24.\" BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 25.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 26.\" AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 27.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 28.\" OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" 31.Dd July 11, 2010 32.Dt UDEV 3 33.Os 34.Sh NAME 35.Nm udev_new , 36.Nm udev_ref , 37.Nm udev_unref , 38.Nm udev_get_dev_path , 39.Nm udev_set_userdata , 40.Nm udev_get_userdata 41.Nd general udev functions 42.Sh LIBRARY 43.Lb libdevattr 44.Sh SYNOPSIS 45.In devattr.h 46.Ft struct udev * 47.Fn udev_new "void" 48.Ft struct udev * 49.Fn udev_ref "struct udev *udev_ctx" 50.Ft void 51.Fn udev_unref "struct udev *udev_ctx" 52.Ft const char * 53.Fn udev_get_dev_path "struct udev *udev_ctx" 54.Ft void 55.Fn udev_set_userdata "struct udev *udev_ctx" "void *userdata" 56.Ft void * 57.Fn udev_get_userdata "struct udev *udev_ctx" 58.Sh DESCRIPTION 59The 60.Fn udev_new 61function returns a new udev context. 62This is needed as a context for all other libdevattr functions. 63The returned context has a refcount of 1. 64This function returns 65.Dv NULL 66if no udev context could be created, which usually happens when 67the udevd daemon is not running. 68.Pp 69The 70.Fn udev_ref 71and 72.Fn udev_unref 73functions increase or decrease the reference count on a udev object respectively. 74When the reference count drops to 0, the object is automatically destroyed. 75The 76.Fn udev_ref 77function returns the same object that was passed in. 78.Pp 79The 80.Fn udev_get_dev_path 81function returns the path to the system device directory. 82.Pp 83The 84.Fn udev_set_userdata 85function allows the consumer to associate some 86.Fa userdata 87to the specified 88.Fa udev_ctx . 89The 90.Fn udev_get_userdata 91function returns the currently associated user data. 92.Sh SEE ALSO 93.Xr devattr 3 , 94.Xr udev_device 3 , 95.Xr udev_enumerate 3 , 96.Xr udev_monitor 3 , 97.Xr udevd 8 98