.\"
.\" Copyright (c) 1996 Julian Elischer
.\"
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.\" $FreeBSD: src/share/man/man9/at_exit.9,v 1.10.2.7 2001/12/17 11:30:18 ru Exp $
.\" $DragonFly: src/share/man/man9/at_exit.9,v 1.2 2003/06/17 04:37:01 dillon Exp $
.\" "
.Dd August 15, 1996
.Os
.Dt AT_EXIT 9
.Sh NAME
.Nm at_exit ,
.Nm rm_at_exit
.Nd ask that a function be run at exit
.Sh SYNOPSIS
.In sys/types.h
.In sys/systm.h
.Ft typedef\ void ( exitlist_fn ) ( struct\ proc\ * ) ;
.Pp
.Ft int
.Fn at_exit "exitlist_fn func"
.Ft int
.Fn rm_at_exit "exitlist_fn func"
.Sh DESCRIPTION
The
.Nm
facility allows a kernel module to ensure that it is notified
at any process exit.
The function
.Fa func
is called with the a pointer to the exiting process's proc structure.
.Pp
If the requirement for notification is removed, then the function
.Fn rm_at_exit
must be called with the exact
.Fa func
argument as the corresponding call to
.Fn at_exit .
.Sh RETURN VALUES
The
.Fa at_exit
function returns an errno, 0 meaning success.  The
.Fn rm_at_exit
function returns the number of items removed (should be 0 or 1).
.Sh SEE ALSO
.Xr _exit 2
.Sh HISTORY
The
.Fn at_exit
function appeared in
.Fx 2.2 .
.Sh AUTHORS
The function was written by
.An Julian Elischer Aq julian@FreeBSD.org .