1.\" $OpenBSD: startuphook_establish.9,v 1.5 2007/05/31 19:20:01 jmc 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 $Mdocdate: May 31 2007 $ 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.Fd #include <sys/types.h> 37.Fd #include <sys/systm.h> 38.Ft void * 39.Fn startuphook_establish "void (*fn)(void *)" "void *arg" 40.Ft void 41.Fn startuphook_disestablish "void *cookie" 42.Sh DESCRIPTION 43The 44.Fn startuphook_establish 45function adds 46.Fa fn 47to the list of hooks invoked by 48.Xr dostartuphooks 9 49at startup. 50When invoked, the hook function 51.Fa fn 52will be passed 53.Fa arg 54as its only argument. 55.Pp 56The 57.Fn startuphook_disestablish 58function removes the hook described by the opaque pointer 59.Fa cookie 60from the list of hooks to be invoked at startup. 61If 62.Fa cookie 63is invalid, the result of 64.Fn startuphook_disestablish 65is undefined. 66.Pp 67Startup hooks should be used to perform one-time activities 68that must happen immediately before the root and swap devices 69are configured, but after normal device autoconfiguration. 70.Pp 71Startup hooks are, like shutdown hooks, implemented via the more general 72.Xr dohooks 9 73API. 74.Sh RETURN VALUES 75If successful, 76.Fn startuphook_establish 77returns an opaque pointer describing the newly established 78startup hook. 79Otherwise, it returns 80.Dv NULL . 81.Sh EXAMPLES 82It may be appropriate to use a startup hook to provide potential root or 83swap devices that have delayed configuration. 84The 85.Xr iop 4 86shows an example of this usage. 87.Sh SEE ALSO 88.Xr dohooks 9 , 89.Xr doshutdownhooks 9 , 90.Xr dostartuphooks 9 91.Sh BUGS 92The names are clumsy, at best. 93