STARTUPHOOK_ESTABLISH(9) OpenBSD Kernel Manual STARTUPHOOK_ESTABLISH(9)NAME
startuphook_establish, startuphook_disestablish - add or remove a startup
hook
SYNOPSIS
#include <sys/types.h>
#include <sys/systm.h>
void *
startuphook_establish(void (*fn)(void *), void *arg);
void
startuphook_disestablish(void *cookie);
DESCRIPTION
The startuphook_establish() function adds fn to the list of hooks invoked
by dostartuphooks(9) at startup. When invoked, the hook function fn will
be passed arg as its only argument.
The startuphook_disestablish() function removes the hook described by the
opaque pointer cookie from the list of hooks to be invoked at startup.
If cookie is invalid, the result of startuphook_disestablish() is
undefined.
Startup hooks should be used to perform one-time activities that must
happen immediately before the root and swap devices are configured, but
after normal device autoconfiguration.
Startup hooks are, like shutdown hooks, implemented via the more general
dohooks(9) API.
RETURN VALUES
If successful, startuphook_establish() returns an opaque pointer
describing the newly established startup hook. Otherwise, it returns
NULL.
EXAMPLES
It may be appropriate to use a startup hook to provide potential root or
swap devices that have delayed configuration. The iop(4) shows an
example of this usage.
SEE ALSOdohooks(9), doshutdownhooks(9), dostartuphooks(9)BUGS
The names are clumsy, at best.
OpenBSD 4.9 May 31, 2007 OpenBSD 4.9
