.\"
.\" Copyright (c) 1999 Chris Costello
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.\" $FreeBSD: head/lib/libc/sys/modstat.2 213573 2010-10-08 12:40:16Z uqs $
.\"
.Dd July 15, 2008
.Dt MODSTAT 2
.Os
.Sh NAME
.Nm modstat
.Nd get status of kernel module
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In sys/param.h
.In sys/module.h
.Ft int
.Fn modstat "int modid" "struct module_stat *stat"
.Sh DESCRIPTION
The
.Fn modstat
system call writes the info for the kernel module referred to by
.Fa modid
into
.Fa stat .
.Bd -literal
struct module_stat {
	int         version;        /* set to sizeof(module_stat) */
	char        name[MAXMODNAME];
	int         refs;
	int         id;
	modspecific_t data;
};
typedef union modspecific {
	int         intval;
	u_int       uintval;
	long        longval;
	u_long      ulongval;
} modspecific_t;
.Ed
.Bl -tag -width XXXaddress
.It version
This field is set to the size of the structure mentioned above by the code
calling
.Fn modstat ,
and not
.Fn modstat
itself.
.It name
The name of the module referred to by
.Fa modid .
.It refs
The number of modules referenced by
.Fa modid .
.It id
The id of the module specified in
.Fa modid .
.It data
Module specific data.
.El
.Sh RETURN VALUES
.Rv -std modstat
.Sh ERRORS
The information for the module referred to by
.Fa modid
is filled into the structure pointed to by
.Fa stat
unless:
.Bl -tag -width Er
.It Bq Er ENOENT
The module was not found (probably not loaded).
.It Bq Er EINVAL
The version specified in the
.Fa version
field of stat is not the proper version.
You would need to rebuild world, the
kernel, or your application, if this error occurs, given that you did properly
fill in the
.Fa version
field.
.It Bq Er EFAULT
There was a problem copying one, some, or all of the fields into
.Fa stat
in the
.Xr copyout 9
function.
.El
.Sh SEE ALSO
.Xr kldfind 2 ,
.Xr kldfirstmod 2 ,
.Xr kldload 2 ,
.Xr kldnext 2 ,
.Xr kldstat 2 ,
.Xr kldsym 2 ,
.Xr kldunload 2 ,
.Xr modfind 2 ,
.Xr modfnext 2 ,
.Xr modnext 2 ,
.Xr kld 4 ,
.Xr kldstat 8
.Sh HISTORY
The
.Nm kld
interface first appeared in
.Fx 3.0 .