1.\" $OpenBSD: startuphook_establish.9,v 1.2 2001/07/28 00:09:24 mpech Exp $ 2.\" 3.\" Copyright (c) 1995 Niklas Hallqvist. 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. The name of the author may not be used to endorse or promote products 15.\" derived from this software without specific prior written permission 16.\" 17.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27.\" 28.Dd July 27 2001 29.Dt STARTUPHOOK_ESTABLISH 9 30.Os 31.Sh NAME 32.Nm startuphook_establish , 33.Nm startuphook_disestablish 34.Nd add or remove a startup hook 35.Sh SYNOPSIS 36.Ft void * 37.Fn startuphook_establish "void (*fn)(void *)" "void *arg" 38.Ft void 39.Fn startuphook_disestablish "void *cookie" 40.Sh DESCRIPTION 41The 42.Fn startuphook_establish 43function adds 44.Fa fn 45to the list of hooks invoked by 46.Xr dostartuphooks 9 47at startup. 48When invoked, the hook function 49.Fa fn 50will be passed 51.Fa arg 52as its only argument. 53.Pp 54The 55.Fn startuphook_disestablish 56function removes the hook described by the opaque pointer 57.Fa cookie 58from the list of hooks to be invoked at startup. 59If 60.Fa cookie 61is invalid, the result of 62.Fn startuphook_disestablish 63is undefined. 64.Pp 65Startup hooks should be used to perform one-time activities 66that must happen immediately before the root and swap devices 67are configured, but after normal device autoconfiguration. 68.Pp 69Startup hooks are, like shutdown hooks, implemented via the more general 70.Xr dohooks 9 71API. 72.Sh RETURN VALUES 73If successful, 74.Fn startuphook_establish 75returns an opaque pointer describing the newly established 76startup hook. 77Otherwise, it returns 78.Dv NULL . 79.Sh EXAMPLES 80It may be appropriate to use a startup hook to provide potential root or 81swap devices that have delayed configuration. 82The 83.Xr iop 4 84shows an example of this usage. 85.Sh SEE ALSO 86.Xr dohooks 9 , 87.Xr doshutdownhooks 9 , 88.Xr dostartuphooks 9 89.Sh BUGS 90The names are clumsy, at best. 91