OpenBSD-4.6/share/man/man9/dohooks.9

.\"	$OpenBSD: dohooks.9,v 1.5 2007/05/31 19:20:00 jmc Exp $
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.Dd $Mdocdate: May 31 2007 $
.Dt DOHOOKS 9
.Os
.Sh NAME
.Nm dohooks
.Nd run all hooks in a list
.Sh SYNOPSIS
.Fd #include <sys/types.h>
.Fd #include <sys/systm.h>
.Ft void
.Fn dohooks "struct hook_desc_head *head" "int flags"
.Sh DESCRIPTION
The
.Fn dohooks
function invokes all hooks established using the
.Xr hook_establish 9
function.
Hooks are called in the order of the TAILQ that
.Fa head
points to, however
.Xr hook_establish 9
can put the hooks either at the head or the tail of that queue,
making it possible to call the hooks either in the order of
establishment, or its reverse.
.Pp
The flags can specify
.Dv HOOK_REMOVE
to remove already processed hooks from the hook list and
.Dv HOOK_FREE
to also free them.
In most cases either no flags should be used or
.Dv HOOK_REMOVE
and
.Dv HOOK_FREE
at the same time, since just HOOK_REMOVE will drop the only reference to
allocated memory and should only be used in situations where freeing
memory would be illegal and unnecessary.
.Pp
This function is used to implement the
.Xr doshutdownhooks 9
as well as the
.Xr dostartuphooks 9
macros.
.Sh SEE ALSO
.Xr doshutdownhooks 9 ,
.Xr dostartuphooks 9 ,
.Xr hook_establish 9