1994-05-26 05:23:31 +00:00
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.\" Copyright (c) 1993
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.\" The Regents of the University of California. All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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2017-02-28 23:42:47 +00:00
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.\" 3. Neither the name of the University nor the names of its contributors
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1994-05-26 05:23:31 +00:00
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.\" may be used to endorse or promote products derived from this software
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.\" without specific prior written permission.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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1994-09-23 19:04:02 +00:00
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.\" From: @(#)sysctl.8 8.1 (Berkeley) 6/6/93
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1994-05-26 05:23:31 +00:00
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.\"
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2022-12-25 06:57:13 +00:00
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.Dd December 24, 2022
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1994-05-26 05:23:31 +00:00
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.Dt SYSCTL 8
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.Os
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.Sh NAME
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.Nm sysctl
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.Nd get or set kernel state
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.Sh SYNOPSIS
|
2000-11-20 16:52:27 +00:00
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.Nm
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2022-12-25 06:57:13 +00:00
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.Op Fl bdeFhilNnoTtqWx
|
2015-02-13 01:20:37 +00:00
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.Op Fl B Ar bufsize
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2012-12-13 23:32:47 +00:00
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.Op Fl f Ar filename
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2018-03-09 23:37:19 +00:00
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.Ar name Ns Op = Ns Ar value Ns Op , Ns Ar value
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2001-05-28 12:15:45 +00:00
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.Ar ...
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2000-11-20 16:52:27 +00:00
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.Nm
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2022-12-25 06:57:13 +00:00
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.Op Fl bdeFhlNnoTtqWx
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2015-02-13 01:20:37 +00:00
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.Op Fl B Ar bufsize
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2001-05-28 12:15:45 +00:00
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.Fl a
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1994-05-26 05:23:31 +00:00
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.Sh DESCRIPTION
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The
|
1997-10-20 12:53:54 +00:00
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.Nm
|
2001-05-28 12:15:45 +00:00
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utility retrieves kernel state and allows processes with appropriate
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privilege to set kernel state.
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2001-07-05 11:22:50 +00:00
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The state to be retrieved or set is described using a
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.Dq Management Information Base
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.Pq Dq MIB
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style name, described as a dotted set of
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2001-05-28 12:15:45 +00:00
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components.
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1995-12-21 12:39:25 +00:00
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.Pp
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1997-10-20 12:53:54 +00:00
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The following options are available:
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.Bl -tag -width indent
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.It Fl A
|
2001-05-28 12:15:45 +00:00
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Equivalent to
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2001-07-05 11:22:50 +00:00
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.Fl o a
|
2001-05-28 12:15:45 +00:00
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(for compatibility).
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.It Fl a
|
2022-03-20 17:41:03 +00:00
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|
List all the currently available values except for those which are
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opaque or excluded from listing via the
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.Dv CTLFLAG_SKIP
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flag.
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2001-05-28 12:15:45 +00:00
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This option is ignored if one or more variable names are specified on
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the command line.
|
2001-05-29 00:17:17 +00:00
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.It Fl b
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Force the value of the variable(s) to be output in raw, binary format.
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No names are printed and no terminating newlines are output.
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This is mostly useful with a single variable.
|
2015-02-13 01:20:37 +00:00
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.It Fl B Ar bufsize
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|
Set the buffer size to read from the
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.Nm
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|
to
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.Ar bufsize .
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|
This is necessary for a
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.Nm
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|
that has variable length, and the probe value of 0 is a valid length, such as
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.Va kern.arandom .
|
2001-12-16 02:55:41 +00:00
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.It Fl d
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|
Print the description of the variable instead of its value.
|
2001-10-30 20:15:32 +00:00
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.It Fl e
|
2001-10-31 15:57:55 +00:00
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|
Separate the name and the value of the variable(s) with
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.Ql = .
|
2001-10-30 20:15:32 +00:00
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|
|
This is useful for producing output which can be fed back to the
|
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|
.Nm
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|
|
utility.
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|
This option is ignored if either
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.Fl N
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|
or
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.Fl n
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is specified, or a variable is being set.
|
2012-12-13 23:32:47 +00:00
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.It Fl f Ar filename
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Specify a file which contains a pair of name and value in each line.
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.Nm
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|
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|
reads and processes the specified file first and then processes the name
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|
and value pairs in the command line argument.
|
2022-12-25 06:57:13 +00:00
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.It Fl F
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|
Print the format of the variable.
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|
|
This is additional information to describe the type of the variable and
|
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|
|
most useful with struct types such as clockinfo, timeval, and loadavg.
|
2003-11-07 16:33:45 +00:00
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.It Fl h
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|
Format output for human, rather than machine, readability.
|
2010-01-31 19:33:25 +00:00
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.It Fl i
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Ignore unknown OIDs.
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|
The purpose is to make use of
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|
.Nm
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|
|
for collecting data from a variety of machines (not all of which
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|
|
|
are necessarily running exactly the same software) easier.
|
2022-12-25 06:57:13 +00:00
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.It Fl l
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|
Show the length of variables along with their values.
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|
This option cannot be combined with the
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|
|
.Fl N
|
|
|
|
option.
|
2001-01-14 19:08:58 +00:00
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|
.It Fl N
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|
|
|
Show only variable names, not their values.
|
2001-05-28 12:15:45 +00:00
|
|
|
This is particularly useful with shells that offer programmable
|
|
|
|
completion.
|
|
|
|
To enable completion of variable names in
|
2005-07-14 20:29:08 +00:00
|
|
|
.Xr zsh 1 Pq Pa ports/shells/zsh ,
|
2001-05-28 12:15:45 +00:00
|
|
|
use the following code:
|
2001-07-05 11:22:50 +00:00
|
|
|
.Bd -literal -offset indent
|
2001-05-28 12:15:45 +00:00
|
|
|
listsysctls () { set -A reply $(sysctl -AN ${1%.*}) }
|
|
|
|
compctl -K listsysctls sysctl
|
|
|
|
.Ed
|
2004-12-05 23:44:52 +00:00
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|
.Pp
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|
To enable completion of variable names in
|
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|
|
.Xr tcsh 1 ,
|
|
|
|
use:
|
2005-01-10 16:17:34 +00:00
|
|
|
.Pp
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|
.Dl "complete sysctl 'n/*/`sysctl -Na`/'"
|
1997-10-20 12:53:54 +00:00
|
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|
.It Fl n
|
2020-08-22 11:59:14 +00:00
|
|
|
Do not show variable names.
|
2001-05-28 12:15:45 +00:00
|
|
|
This option is useful for setting shell variables.
|
2001-07-05 11:22:50 +00:00
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|
|
For instance, to save the pagesize in variable
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|
|
.Va psize ,
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|
|
use:
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|
.Pp
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|
.Dl "set psize=`sysctl -n hw.pagesize`"
|
2001-05-29 00:17:17 +00:00
|
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|
.It Fl o
|
2001-05-28 12:15:45 +00:00
|
|
|
Show opaque variables (which are normally suppressed).
|
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|
|
The format and length are printed, as well as a hex dump of the first
|
|
|
|
sixteen bytes of the value.
|
2005-09-15 16:08:04 +00:00
|
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|
.It Fl q
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|
|
Suppress some warnings generated by
|
|
|
|
.Nm
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|
|
|
to standard error.
|
2012-12-11 01:28:06 +00:00
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|
.It Fl T
|
2015-02-13 01:20:37 +00:00
|
|
|
Display only variables that are settable via loader (CTLFLAG_TUN).
|
2015-12-10 02:11:42 +00:00
|
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|
.It Fl t
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|
|
|
Print the type of the variable.
|
2012-12-11 01:28:06 +00:00
|
|
|
.It Fl W
|
2013-11-12 17:44:29 +00:00
|
|
|
Display only writable variables that are not statistical.
|
2012-12-11 01:28:06 +00:00
|
|
|
Useful for determining the set of runtime tunable sysctls.
|
2001-05-28 12:15:45 +00:00
|
|
|
.It Fl X
|
|
|
|
Equivalent to
|
2001-07-05 11:22:50 +00:00
|
|
|
.Fl x a
|
2001-05-28 12:15:45 +00:00
|
|
|
(for compatibility).
|
|
|
|
.It Fl x
|
|
|
|
As
|
|
|
|
.Fl o ,
|
|
|
|
but prints a hex dump of the entire value instead of just the first
|
|
|
|
few bytes.
|
1997-10-20 12:53:54 +00:00
|
|
|
.El
|
1994-05-26 05:23:31 +00:00
|
|
|
.Pp
|
|
|
|
The information available from
|
1997-10-20 12:53:54 +00:00
|
|
|
.Nm
|
2011-01-17 23:36:53 +00:00
|
|
|
consists of integers, strings, and opaque types.
|
2002-07-06 19:35:14 +00:00
|
|
|
The
|
|
|
|
.Nm
|
|
|
|
utility
|
1995-12-21 12:39:25 +00:00
|
|
|
only knows about a couple of opaque types, and will resort to hexdumps
|
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|
|
for the rest.
|
|
|
|
The opaque information is much more useful if retrieved by special
|
1994-05-26 05:23:31 +00:00
|
|
|
purpose programs such as
|
2003-06-08 12:57:39 +00:00
|
|
|
.Xr ps 1 ,
|
|
|
|
.Xr systat 1 ,
|
1994-05-26 05:23:31 +00:00
|
|
|
and
|
2003-06-08 12:57:39 +00:00
|
|
|
.Xr netstat 1 .
|
1995-12-21 12:39:25 +00:00
|
|
|
.Pp
|
2003-05-18 00:27:02 +00:00
|
|
|
Some of the variables which cannot be modified during normal system
|
|
|
|
operation can be initialized via
|
|
|
|
.Xr loader 8
|
|
|
|
tunables.
|
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|
|
This can for example be done by setting them in
|
2003-05-17 01:01:03 +00:00
|
|
|
.Xr loader.conf 5 .
|
2003-05-18 00:27:02 +00:00
|
|
|
Please refer to
|
|
|
|
.Xr loader.conf 5
|
|
|
|
for more information on which tunables are available and how to set them.
|
2003-05-17 01:01:03 +00:00
|
|
|
.Pp
|
1996-01-30 13:52:50 +00:00
|
|
|
The string and integer information is summarized below.
|
2022-12-13 19:48:25 +00:00
|
|
|
For a detailed description of these variables see
|
1994-05-26 05:23:31 +00:00
|
|
|
.Xr sysctl 3 .
|
1995-12-21 12:39:25 +00:00
|
|
|
.Pp
|
1994-05-26 05:23:31 +00:00
|
|
|
The changeable column indicates whether a process with appropriate
|
|
|
|
privilege can change the value.
|
2011-01-17 23:43:03 +00:00
|
|
|
String and integer values can be set using
|
2002-03-10 09:53:39 +00:00
|
|
|
.Nm .
|
2002-01-16 06:55:30 +00:00
|
|
|
.Bl -column security.bsd.unprivileged_read_msgbuf integerxxx
|
2012-03-26 15:18:14 +00:00
|
|
|
.It Sy "Name Type Changeable"
|
|
|
|
.It "kern.ostype string no"
|
|
|
|
.It "kern.osrelease string no"
|
|
|
|
.It "kern.osrevision integer no"
|
|
|
|
.It "kern.version string no"
|
|
|
|
.It "kern.maxvnodes integer yes"
|
|
|
|
.It "kern.maxproc integer no"
|
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|
.It "kern.maxprocperuid integer yes"
|
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|
.It "kern.maxfiles integer yes"
|
|
|
|
.It "kern.maxfilesperproc integer yes"
|
|
|
|
.It "kern.argmax integer no"
|
|
|
|
.It "kern.securelevel integer raise only"
|
|
|
|
.It "kern.hostname string yes"
|
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|
|
.It "kern.hostid integer yes"
|
|
|
|
.It "kern.clockrate struct no"
|
|
|
|
.It "kern.posix1version integer no"
|
|
|
|
.It "kern.ngroups integer no"
|
|
|
|
.It "kern.job_control integer no"
|
|
|
|
.It "kern.saved_ids integer no"
|
|
|
|
.It "kern.boottime struct no"
|
|
|
|
.It "kern.domainname string yes"
|
|
|
|
.It "kern.filedelay integer yes"
|
|
|
|
.It "kern.dirdelay integer yes"
|
|
|
|
.It "kern.metadelay integer yes"
|
2017-09-16 16:23:00 +00:00
|
|
|
.It "kern.osreldate integer no"
|
2012-03-26 15:18:14 +00:00
|
|
|
.It "kern.bootfile string yes"
|
|
|
|
.It "kern.corefile string yes"
|
|
|
|
.It "kern.logsigexit integer yes"
|
|
|
|
.It "security.bsd.suser_enabled integer yes"
|
|
|
|
.It "security.bsd.see_other_uids integer yes"
|
|
|
|
.It "security.bsd.unprivileged_proc_debug integer yes"
|
|
|
|
.It "security.bsd.unprivileged_read_msgbuf integer yes"
|
|
|
|
.It "vm.loadavg struct no"
|
|
|
|
.It "hw.machine string no"
|
|
|
|
.It "hw.model string no"
|
|
|
|
.It "hw.ncpu integer no"
|
|
|
|
.It "hw.byteorder integer no"
|
|
|
|
.It "hw.physmem integer no"
|
|
|
|
.It "hw.usermem integer no"
|
|
|
|
.It "hw.pagesize integer no"
|
|
|
|
.It "hw.floatingpoint integer no"
|
|
|
|
.It "hw.machine_arch string no"
|
|
|
|
.It "hw.realmem integer no"
|
|
|
|
.It "machdep.adjkerntz integer yes"
|
|
|
|
.It "machdep.disable_rtc_set integer yes"
|
|
|
|
.It "machdep.guessed_bootdev string no"
|
|
|
|
.It "user.cs_path string no"
|
|
|
|
.It "user.bc_base_max integer no"
|
|
|
|
.It "user.bc_dim_max integer no"
|
|
|
|
.It "user.bc_scale_max integer no"
|
|
|
|
.It "user.bc_string_max integer no"
|
|
|
|
.It "user.coll_weights_max integer no"
|
|
|
|
.It "user.expr_nest_max integer no"
|
|
|
|
.It "user.line_max integer no"
|
|
|
|
.It "user.re_dup_max integer no"
|
|
|
|
.It "user.posix2_version integer no"
|
|
|
|
.It "user.posix2_c_bind integer no"
|
|
|
|
.It "user.posix2_c_dev integer no"
|
|
|
|
.It "user.posix2_char_term integer no"
|
|
|
|
.It "user.posix2_fort_dev integer no"
|
|
|
|
.It "user.posix2_fort_run integer no"
|
|
|
|
.It "user.posix2_localedef integer no"
|
|
|
|
.It "user.posix2_sw_dev integer no"
|
|
|
|
.It "user.posix2_upe integer no"
|
|
|
|
.It "user.stream_max integer no"
|
|
|
|
.It "user.tzname_max integer no"
|
2020-10-30 19:37:53 +00:00
|
|
|
.It "user.localbase string no"
|
1994-05-26 05:23:31 +00:00
|
|
|
.El
|
2005-01-18 10:09:38 +00:00
|
|
|
.Sh FILES
|
|
|
|
.Bl -tag -width ".In netinet/icmp_var.h" -compact
|
|
|
|
.It In sys/sysctl.h
|
|
|
|
definitions for top level identifiers, second level kernel and hardware
|
|
|
|
identifiers, and user level identifiers
|
|
|
|
.It In sys/socket.h
|
|
|
|
definitions for second level network identifiers
|
|
|
|
.It In sys/gmon.h
|
|
|
|
definitions for third level profiling identifiers
|
|
|
|
.It In vm/vm_param.h
|
|
|
|
definitions for second level virtual memory identifiers
|
|
|
|
.It In netinet/in.h
|
|
|
|
definitions for third level Internet identifiers and
|
|
|
|
fourth level IP identifiers
|
|
|
|
.It In netinet/icmp_var.h
|
|
|
|
definitions for fourth level ICMP identifiers
|
|
|
|
.It In netinet/udp_var.h
|
|
|
|
definitions for fourth level UDP identifiers
|
|
|
|
.El
|
2018-09-24 20:46:45 +00:00
|
|
|
.Sh EXIT STATUS
|
|
|
|
.Ex -std
|
1994-05-26 05:23:31 +00:00
|
|
|
.Sh EXAMPLES
|
|
|
|
For example, to retrieve the maximum number of processes allowed
|
2000-02-26 16:55:21 +00:00
|
|
|
in the system, one would use the following request:
|
2001-07-05 11:22:50 +00:00
|
|
|
.Pp
|
|
|
|
.Dl "sysctl kern.maxproc"
|
1994-05-26 05:23:31 +00:00
|
|
|
.Pp
|
|
|
|
To set the maximum number of processes allowed
|
2000-02-26 16:55:21 +00:00
|
|
|
per uid to 1000, one would use the following request:
|
2001-07-05 11:22:50 +00:00
|
|
|
.Pp
|
2001-07-30 14:18:14 +00:00
|
|
|
.Dl "sysctl kern.maxprocperuid=1000"
|
1994-05-26 05:23:31 +00:00
|
|
|
.Pp
|
|
|
|
Information about the system clock rate may be obtained with:
|
2001-07-05 11:22:50 +00:00
|
|
|
.Pp
|
|
|
|
.Dl "sysctl kern.clockrate"
|
1994-05-26 05:23:31 +00:00
|
|
|
.Pp
|
1997-10-20 12:53:54 +00:00
|
|
|
Information about the load average history may be obtained with:
|
1995-12-21 12:39:25 +00:00
|
|
|
.Pp
|
2001-07-05 11:22:50 +00:00
|
|
|
.Dl "sysctl vm.loadavg"
|
|
|
|
.Pp
|
|
|
|
More variables than these exist, and the best and likely only place
|
1995-12-21 12:39:25 +00:00
|
|
|
to search for their deeper meaning is undoubtedly the source where
|
|
|
|
they are defined.
|
2001-08-02 12:38:23 +00:00
|
|
|
.Sh COMPATIBILITY
|
|
|
|
The
|
|
|
|
.Fl w
|
|
|
|
option has been deprecated and is silently ignored.
|
1994-05-26 05:23:31 +00:00
|
|
|
.Sh SEE ALSO
|
2000-12-14 16:24:38 +00:00
|
|
|
.Xr sysctl 3 ,
|
2003-05-17 01:01:03 +00:00
|
|
|
.Xr loader.conf 5 ,
|
|
|
|
.Xr sysctl.conf 5 ,
|
|
|
|
.Xr loader 8
|
1994-05-26 05:23:31 +00:00
|
|
|
.Sh HISTORY
|
2002-07-06 19:35:14 +00:00
|
|
|
A
|
|
|
|
.Nm
|
|
|
|
utility first appeared in
|
1996-08-23 00:57:08 +00:00
|
|
|
.Bx 4.4 .
|
1995-12-21 12:39:25 +00:00
|
|
|
.Pp
|
2001-07-05 11:22:50 +00:00
|
|
|
In
|
1997-10-20 12:53:54 +00:00
|
|
|
.Fx 2.2 ,
|
|
|
|
.Nm
|
1996-08-23 00:57:08 +00:00
|
|
|
was significantly remodeled.
|
2005-01-18 10:09:38 +00:00
|
|
|
.Sh BUGS
|
|
|
|
The
|
|
|
|
.Nm
|
|
|
|
utility presently exploits an undocumented interface to the kernel
|
2022-06-30 13:34:58 +00:00
|
|
|
.Xr sysctl 9
|
|
|
|
facility to traverse the sysctl tree and to retrieve format
|
2005-01-18 10:09:38 +00:00
|
|
|
and name information.
|
|
|
|
This correct interface is being thought about for the time being.
|