789 lines
23 KiB
Groff
789 lines
23 KiB
Groff
.\" $NetBSD: sysctl.8,v 1.108 2004/01/22 07:31:53 wiz Exp $
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.\"
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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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.\" 3. Neither the name of the University nor the names of its contributors
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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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.\" @(#)sysctl.8 8.1 (Berkeley) 6/6/93
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.\"
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.Dd January 22, 2004
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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
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.Nm sysctl
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.Op Fl AeMn
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.Oo
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.Fl r |
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.Fl x
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.Oc
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.Op Ar name ...
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.Nm sysctl
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.Op Fl nq
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.Oo
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.Fl r |
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.Fl x
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.Oc
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.Fl w
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.Ar name Ns Li = Ns Ar value ...
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.Nm sysctl
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.Op Fl en
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.Oo
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.Fl r |
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.Fl x
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.Oc
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.Fl a
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.Nm sysctl
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.Op Fl nq
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.Oo
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.Fl r |
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.Fl x
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.Oc
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.Fl f
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.Ar file
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.Sh DESCRIPTION
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The
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.Nm sysctl
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utility retrieves kernel state and allows processes with
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appropriate privilege to set kernel state.
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The state to be retrieved or set is described using a
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``Management Information Base'' (``MIB'') style name,
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described as a dotted set of components.
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The
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.Sq /
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character may also be used as a separator and a leading separator
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character is accepted.
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If
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.Ar name
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specifies a non-leaf node in the MIB, all the nodes underneath
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.Ar name
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will be printed.
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.Pp
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The following options are available:
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.Bl -tag -width indent
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.It Fl A
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List all the known MIB names including tables, unless any MIB
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arguments or
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.Fl f Ar file
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are given.
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Those with string or integer values will be printed as with the
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.Fl a
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flag; for table or structure values that
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.Nm
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is not able to print,
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the name of the utility to retrieve them is given.
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Errors in retrieving or setting values will be directed to stdout
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instead of stderr.
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.It Fl a
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List all the currently available string or integer values.
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The use of a solitary separator character (either
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.Sq \&.
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or
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.Sq / )
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by
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itself has the same effect.
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Any given
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.Ar name
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arguments are ignored if this option is specified.
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.It Fl e
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Separate the name and the value of the variable(s) with
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.Ql = .
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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
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.Fl n
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is specified or a variable is being set.
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.It Fl f
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Specifies the name of a file to read and process.
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Blank lines and comments (beginning with
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.Ql # )
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are ignored.
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Line continuations with
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.Ql \e
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are permitted.
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Remaining lines are processed similarly to
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command line arguments of the form
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.Ar name
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or
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.Ar name Ns Li = Ns Ar value .
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The
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.Fl w
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flag is implied by
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.Fl f .
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Any
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.Ar name
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arguments are ignored.
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.It Fl M
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Makes
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.Nm
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print the MIB instead of any of the actual values contained in the
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MIB.
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This causes the entire MIB to be printed unless specific MIB arguments
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or
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.Fl f Ar file
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are also given.
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.It Fl n
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Specifies that the printing of the field name should be
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suppressed and that only its value should be output.
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This flag is useful for setting shell variables.
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For example, to save the pagesize in variable psize, use:
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.Bd -literal -offset indent -compact
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set psize=`sysctl -n hw.pagesize`
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.Ed
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.It Fl q
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Used to indicate that nothing should be printed for writes unless an
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error is detected.
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.It Fl r
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Raw output form.
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Values printed are in their raw binary forms as retrieved directly
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from the kernel.
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Some additional nodes that
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.Nm
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cannot print directly can be retrieved with this flag.
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This option conflicts with the
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.Fl x
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option.
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.It Fl w
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Sets the MIB style name given to the value given.
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The MIB style name and value must be separated by
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.Ql =
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with no whitespace.
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Only integral and string values can be set via this method.
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.It Fl x
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Makes
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.Nm
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print the requested value in a hexadecimal representation instead of
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its regular form.
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If specified more than once, the output for each value resembles that of
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.Xr hexdump 1
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when given the
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.Fl C
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flag.
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This option conflicts with the
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.Fl r
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option.
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.Pp
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.El
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The
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.Ql proc
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top-level MIB has a special semantic: it represent per-process values
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and as such may differ from one process to another.
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The second-level name is the pid of the process (in decimal form),
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or the special word
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.Ql curproc .
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For variables below
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.Ql proc. Ns Ao pid Ac Ns .rlimit ,
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the integer value may be replaced
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with the string
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.Ql unlimited
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if it matches the magic value used to disable
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a limit.
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.Pp
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The information available from
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.Nm sysctl
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consists of integers, strings, and tables.
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The tabular information can only be retrieved by special
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purpose programs such as
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.Nm ps ,
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.Nm systat ,
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and
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.Nm netstat .
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The string and integer information is summarized below.
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For a detailed description of these variable see
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.Xr sysctl 3 .
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The changeable column indicates whether a process with appropriate
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privilege can change the value.
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.Bl -column proc.xpidx.rlimit.coredumpsize.hardxxxxxx integerxxx
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.It Sy Name Type Changeable
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.It ddb.fromconsole integer yes
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.It ddb.lines integer yes
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.It ddb.maxoff integer yes
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.It ddb.maxwidth integer yes
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.It ddb.onpanic integer yes
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.It ddb.radix integer yes
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.It ddb.tabstops integer yes
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.It hw.alignbytes integer no
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.It hw.byteorder integer no
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.It hw.disknames string no
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.It hw.diskstats struct no
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.It hw.machine string no
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.It hw.machine_arch string no
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.It hw.model string no
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.It hw.ncpu integer no
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.It hw.pagesize integer no
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.It hw.physmem integer no
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.It hw.physmem64 quad no
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.It hw.usermem integer no
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.It hw.usermem64 quad no
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.It hw.cnmagic string yes
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.It kern.argmax integer no
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.It kern.autonicetime integer yes
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.It kern.autoniceval integer yes
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.It kern.boottime struct no
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.It kern.ccpu integer no
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.It kern.chown_restricted integer no
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.It kern.clockrate struct no
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.It kern.consdev integer no
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.It kern.cp_time struct no
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.It kern.defcorename string yes
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.It kern.domainname string yes
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.It kern.drivers struct no
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.It kern.forkfsleep integer yes
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.It kern.fscale integer no
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.It kern.fsync integer no
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.It kern.hostid integer yes
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.It kern.hostname string yes
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.It kern.iov_max integer no
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.It kern.job_control integer no
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.It kern.labeloffset integer no
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.It kern.labelsector integer no
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.It kern.link_max integer no
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.It kern.login_name_max integer no
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.It kern.logsigexit integer yes
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.It kern.max_canon integer no
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.It kern.max_input integer no
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.It kern.maxfiles integer yes
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.It kern.maxpartitions integer no
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.It kern.maxproc integer yes
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.It kern.maxptys integer yes, special
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.It kern.maxvnodes integer raise only
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.It kern.mapped_files integer no
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.It kern.maxphys integer no
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.It kern.memlock integer no
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.It kern.memlock_range integer no
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.It kern.memory_protection integer no
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.It kern.mbuf.mblowat integer yes
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.It kern.mbuf.mcllowat integer yes
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.It kern.mbuf.mclsize integer no
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.It kern.mbuf.msize integer no
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.It kern.mbuf.nmbclusters integer raise only
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.It kern.monotonic_clock integer no
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.It kern.msgbuf struct no
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.It kern.msgbufsize integer no
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.It kern.name_max integer no
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.It kern.ngroups integer no
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.It kern.no_trunc integer no
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.It kern.ntptime struct no
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.It kern.osrelease string no
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.It kern.osrevision integer no
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.It kern.ostype string no
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.It kern.path_max integer no
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.It kern.pipe.maxkvasz integer yes
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.It kern.pipe.maxloankvasz integer yes
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.It kern.pipe.maxbigpipes integer yes
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.It kern.pipe.nbigpipes integer no
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.It kern.pipe.kvasize integer no
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.It kern.posix1version integer no
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.It kern.posix_barriers integer no
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.It kern.posix_reader_writer_locks integer no
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.It kern.posix_semaphores integer no
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.It kern.posix_spin_locks integer no
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.It kern.posix_timers integer no
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.It kern.posix_threads integer no
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.It kern.proc2 struct no
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.It kern.proc_args string yes
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.It kern.rawpartition integer no
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.It kern.root_device string no
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.It kern.root_partition integer no
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.It kern.rtc_offset integer no
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.It kern.saved_ids integer no
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.It kern.sbmax integer yes
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.It kern.securelevel integer raise only
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.It kern.somaxkva integer yes
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.It kern.synchronized_io integer no
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.It kern.sysvipc_info struct no
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.It kern.sysvmsg integer no
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.It kern.sysvsem integer no
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.It kern.sysvshm integer no
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.It kern.timex struct no
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.It kern.tkstat.nin quad no
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.It kern.tkstat.nout quad no
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.It kern.tkstat.cancc quad no
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.It kern.tkstat.rawcc quad no
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.It kern.urnd integer no
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.It kern.vdisable integer no
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.It kern.version string no
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.It machdep.console_device dev_t no
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.It net.bpf.maxbufsize integer yes
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.It net.inet.icmp.maskrepl integer yes
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.It net.inet.icmp.errppslimit integer yes
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.It net.inet.icmp.rediraccept integer yes
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.It net.inet.icmp.redirtimeout integer yes
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.It net.inet.ip.allowsrcrt integer yes
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.It net.inet.ip.anonportmax integer yes
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.It net.inet.ip.anonportmin integer yes
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.It net.inet.ip.checkinterface integer yes
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.It net.inet.ip.directed-broadcast integer yes
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.It net.inet.ip.forwarding integer yes
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.It net.inet.ip.forwsrcrt integer yes
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.It net.inet.ip.maxfragpacket integer yes
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.It net.inet.ip.lowportmax integer yes
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.It net.inet.ip.lowportmin integer yes
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.It net.inet.ip.mtudisc integer yes
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.It net.inet.ip.mtudisctimeout integer yes
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.It net.inet.ip.redirect integer yes
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.It net.inet.ip.subnetsarelocal integer yes
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.It net.inet.ip.ttl integer yes
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.It net.inet.ipsec.ah_cleartos integer yes
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.It net.inet.ipsec.ah_net_deflev integer yes
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.It net.inet.ipsec.ah_offsetmask integer yes
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.It net.inet.ipsec.ah_trans_deflev integer yes
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.It net.inet.ipsec.def_policy integer yes
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.It net.inet.ipsec.dfbit integer yes
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.It net.inet.ipsec.ecn integer yes
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.It net.inet.ipsec.esp_net_deflev integer yes
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.It net.inet.ipsec.esp_trans_deflev integer yes
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.It net.inet.ipsec.inbound_call_ike integer yes
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.It net.inet.tcp.ack_on_push integer yes
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.It net.inet.tcp.compat_42 integer yes
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.It net.inet.tcp.cwm integer yes
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.It net.inet.tcp.cwm_burstsize integer yes
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.It net.inet.tcp.init_win integer yes
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.It net.inet.tcp.init_win_local integer yes
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.It net.inet.tcp.keepcnt integer yes
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.It net.inet.tcp.keepidle integer yes
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.It net.inet.tcp.keepintvl integer yes
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.It net.inet.tcp.log_refused integer yes
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.It net.inet.tcp.mss_ifmtu integer yes
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.It net.inet.tcp.mssdflt integer yes
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.It net.inet.tcp.recvspace integer yes
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.It net.inet.tcp.rfc1323 integer yes
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.It net.inet.tcp.rstppslimit integer yes
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.It net.inet.tcp.sack integer yes
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.It net.inet.tcp.sendspace integer yes
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.It net.inet.tcp.slowhz integer no
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.It net.inet.tcp.syn_bucket_limit integer yes
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.It net.inet.tcp.syn_cache_interval integer yes
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.It net.inet.tcp.syn_cache_limit integer yes
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.It net.inet.tcp.timestamps integer yes
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.It net.inet.tcp.win_scale integer yes
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.It net.inet.tcp.ident struct no
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.It net.inet.udp.checksum integer yes
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.It net.inet.udp.recvspace integer yes
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.It net.inet.udp.sendspace integer yes
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.It net.inet6.icmp6.errppslimit integer yes
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.It net.inet6.icmp6.mtudisc_hiwat integer yes
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.It net.inet6.icmp6.mtudisc_lowat integer yes
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.It net.inet6.icmp6.nd6_debug integer yes
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.It net.inet6.icmp6.nd6_delay integer yes
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.It net.inet6.icmp6.nd6_maxnudhint integer yes
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.It net.inet6.icmp6.nd6_mmaxtries integer yes
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.It net.inet6.icmp6.nd6_prune integer yes
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|
.It net.inet6.icmp6.nd6_umaxtries integer yes
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|
.It net.inet6.icmp6.nd6_useloopback integer yes
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|
.It net.inet6.icmp6.nodeinfo integer yes
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|
.It net.inet6.icmp6.rediraccept integer yes
|
|
.It net.inet6.icmp6.redirtimeout integer yes
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|
.It net.inet6.ip6.accept_rtadv integer yes
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|
.It net.inet6.ip6.anonportmax integer yes
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|
.It net.inet6.ip6.anonportmin integer yes
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|
.It net.inet6.ip6.auto_flowlabel integer yes
|
|
.It net.inet6.ip6.v6only integer yes
|
|
.It net.inet6.ip6.dad_count integer yes
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|
.It net.inet6.ip6.defmcasthlim integer yes
|
|
.It net.inet6.ip6.forwarding integer yes
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|
.It net.inet6.ip6.gif_hlim integer yes
|
|
.It net.inet6.ip6.hdrnestlimit integer yes
|
|
.It net.inet6.ip6.hlim integer yes
|
|
.It net.inet6.ip6.kame_version string no
|
|
.It net.inet6.ip6.keepfaith integer yes
|
|
.It net.inet6.ip6.log_interval integer yes
|
|
.It net.inet6.ip6.lowportmax integer yes
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|
.It net.inet6.ip6.lowportmin integer yes
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|
.It net.inet6.ip6.maxfragpackets integer yes
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|
.It net.inet6.ip6.maxfrags integer yes
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|
.It net.inet6.ip6.redirect integer yes
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|
.It net.inet6.ip6.rr_prune integer yes
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|
.It net.inet6.ip6.use_deprecated integer yes
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|
.It net.inet6.ipsec6.ah_net_deflev integer yes
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|
.It net.inet6.ipsec6.ah_trans_deflev integer yes
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|
.It net.inet6.ipsec6.def_policy integer yes
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|
.It net.inet6.ipsec6.ecn integer yes
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|
.It net.inet6.ipsec6.esp_net_deflev integer yes
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|
.It net.inet6.ipsec6.esp_trans_deflev integer yes
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|
.It net.inet6.ipsec6.inbound_call_ike integer yes
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|
.It net.inet6.udp6.recvspace integer yes
|
|
.It net.inet6.udp6.sendspace integer yes
|
|
.It net.key.acq_exp_int integer yes
|
|
.It net.key.acq_maxtime integer yes
|
|
.It net.key.ah_keymin integer yes
|
|
.It net.key.debug integer yes
|
|
.It net.key.esp_auth integer yes
|
|
.It net.key.esp_keymin integer yes
|
|
.It net.key.kill_int integer yes
|
|
.It net.key.random_int integer yes
|
|
.It net.key.spi_max_value integer yes
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|
.It net.key.spi_min_value integer yes
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|
.It net.key.spi_try integer yes
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|
.It proc.\*[Lt]pid\*[Gt].corename string yes
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|
.It proc.\*[Lt]pid\*[Gt].rlimit.coredumpsize.hard integer yes
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|
.It proc.\*[Lt]pid\*[Gt].rlimit.coredumpsize.soft integer yes
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|
.It proc.\*[Lt]pid\*[Gt].rlimit.cputime.hard integer yes
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|
.It proc.\*[Lt]pid\*[Gt].rlimit.cputime.soft integer yes
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|
.It proc.\*[Lt]pid\*[Gt].rlimit.datasize.hard integer yes
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|
.It proc.\*[Lt]pid\*[Gt].rlimit.datasize.soft integer yes
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|
.It proc.\*[Lt]pid\*[Gt].rlimit.filesize.hard integer yes
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|
.It proc.\*[Lt]pid\*[Gt].rlimit.filesize.soft integer yes
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|
.It proc.\*[Lt]pid\*[Gt].rlimit.maxproc.hard integer yes
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|
.It proc.\*[Lt]pid\*[Gt].rlimit.maxproc.soft integer yes
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|
.It proc.\*[Lt]pid\*[Gt].rlimit.memorylocked.hard integer yes
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|
.It proc.\*[Lt]pid\*[Gt].rlimit.memorylocked.soft integer yes
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|
.It proc.\*[Lt]pid\*[Gt].rlimit.memoryuse.hard integer yes
|
|
.It proc.\*[Lt]pid\*[Gt].rlimit.memoryuse.soft integer yes
|
|
.It proc.\*[Lt]pid\*[Gt].rlimit.stacksize.hard integer yes
|
|
.It proc.\*[Lt]pid\*[Gt].rlimit.stacksize.soft integer yes
|
|
.It proc.\*[Lt]pid\*[Gt].stopexec int yes
|
|
.It proc.\*[Lt]pid\*[Gt].stopfork int yes
|
|
.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.cs_path string no
|
|
.It user.expr_nest_max integer no
|
|
.It user.line_max 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.posix2_version integer no
|
|
.It user.re_dup_max integer no
|
|
.It vendor.\*[Lt]vendor\*[Gt].* ? vendor specific
|
|
.It vfs.generic.usermount integer yes
|
|
.It vfs.nfs.iothreads integer yes
|
|
.It vm.anonmax integer yes
|
|
.It vm.anonmin integer yes
|
|
.It vm.execmax integer yes
|
|
.It vm.execmin integer yes
|
|
.It vm.filemax integer yes
|
|
.It vm.filemin integer yes
|
|
.It vm.loadavg struct no
|
|
.It vm.nkmempages integer no
|
|
.It vm.uvmexp struct no
|
|
.It vm.uvmexp2 struct no
|
|
.It vm.vmmeter struct no
|
|
.El
|
|
.Pp
|
|
Entries found under
|
|
.Dq vendor. Ns Aq vendor
|
|
are left to be specified (and used) by vendors
|
|
using the
|
|
.Nx
|
|
operating system in their products.
|
|
Values and structure are vendor-defined, and no registry
|
|
exists right now.
|
|
.Sh CREATION AND DELETION
|
|
New nodes are allowed to be created by the superuser when the kernel
|
|
is running at security level 0.
|
|
These new nodes may refer to existing kernel data or to new data that
|
|
is only instrumented by
|
|
.Xr sysctl 3
|
|
itself.
|
|
.Pp
|
|
The syntax for creating new nodes is
|
|
.Dq //create=new.node.path
|
|
followed by one or more of the following attributes separated by
|
|
commas.
|
|
The use of a double separator (both
|
|
.Sq /
|
|
and
|
|
.Sq \&.
|
|
can be used as
|
|
separators) as the prefix tells sysctl that the first series of tokens
|
|
is not a MIB name, but a command.
|
|
It is recommended that the double separator preceding the command not
|
|
be the same as the separator used in naming the MIB entry so as to
|
|
avoid possible parse conflicts.
|
|
The
|
|
.Dq value
|
|
assigned, if one is given, must be last.
|
|
.Pp
|
|
.Bl -bullet -compact
|
|
.It
|
|
.Ar type= Ns Aq Ar T
|
|
where
|
|
.Ar T
|
|
must be one of
|
|
.Dq node ,
|
|
.Dq int ,
|
|
.Dq string ,
|
|
.Dq quad ,
|
|
or
|
|
.Dq struct .
|
|
If the type is omitted, the
|
|
.Dq node
|
|
type is assumed.
|
|
.It
|
|
.Ar size= Ns Aq Ar S
|
|
here,
|
|
.Ar S
|
|
asserts the size of the new node.
|
|
Nodes of type
|
|
.Dq node
|
|
should not have a size set.
|
|
The size may be omitted for nodes of types
|
|
.Dq int
|
|
or
|
|
.Dq quad .
|
|
If the size is omitted for a node of type
|
|
.Dq string ,
|
|
the size will be determined by the length of the given value, or by
|
|
the kernel for kernel strings.
|
|
Nodes of type
|
|
.Dq struct
|
|
must have their size explicitly set.
|
|
.It
|
|
.Ar addr= Ns Aq Ar A
|
|
or
|
|
.Ar symbol= Ns Aq Ar A
|
|
The kernel address of the data being instrumented.
|
|
If
|
|
.Dq symbol
|
|
is used, the symbol must be globally visible to the in-kernel
|
|
.Xr ksyms 4
|
|
driver.
|
|
.It
|
|
.Ar n= Ns Aq Ar N
|
|
The MIB number to be assigned to the new node.
|
|
If no number is specified, the kernel will assign a value.
|
|
.It
|
|
.Ar flags= Ns Aq Ar F
|
|
A concatenated string of single letters that govern the behavior of
|
|
the node.
|
|
Flags currently available are:
|
|
.Bl -tag -width www
|
|
.It a
|
|
Allow anyone to write to the node, if it is writable.
|
|
.It h
|
|
.Dq Hidden .
|
|
.Nm
|
|
must be invoked with
|
|
.Fl A
|
|
or the hidden node must be specifically requested in order to see it
|
|
.It i
|
|
.Dq Immediate .
|
|
Makes the node store data in itself, rather than allocating new space
|
|
for it.
|
|
This is the default for nodes of type
|
|
.Dq int
|
|
and
|
|
.Dq quad .
|
|
This is the opposite of owning data.
|
|
.It o
|
|
.Dq Own .
|
|
When the node is created, separate space will be allocated to store
|
|
the data to be instrumented.
|
|
This is the default for nodes of type
|
|
.Dq string
|
|
and
|
|
.Dq struct
|
|
where it is not possible to guarantee sufficient space to store the
|
|
data in the node itself.
|
|
.It p
|
|
.Dq Private .
|
|
Nodes that are marked private, and children of nodes so marked, are
|
|
only viewable by the superuser.
|
|
Be aware that the immediate data that some nodes may store is not
|
|
necessarily protected by this.
|
|
.It x
|
|
.Dq Hexadecimal .
|
|
Make
|
|
.Nm
|
|
default to hexadecimal display of the retrieved value
|
|
.It r
|
|
.Dq Read-only .
|
|
The data instrumented by the given node is read-only.
|
|
Note that other mechanisms may still exist for changing the data.
|
|
This is the default for nodes that instrument data.
|
|
.It w
|
|
.Dq Writable .
|
|
The data instrumented by the given node is writable at any time.
|
|
This is the default for nodes that can have children.
|
|
.It 1
|
|
.Dq Read-only at securelevel 1 .
|
|
The data instrumented by this node is writable until the securelevel
|
|
reaches or passes securelevel 1.
|
|
Examples of this include some network tunables.
|
|
.It 2
|
|
.Dq Read-only at securelevel 2 .
|
|
The data instrumented by this node is writable until the securelevel
|
|
reaches or passes securelevel 2.
|
|
An example of this is the per-process core filename setting.
|
|
.El
|
|
.Pp
|
|
.It
|
|
.Ar value= Ns Aq Ar V
|
|
An initial starting value for a new node that does not reference
|
|
existing kernel data.
|
|
Initial values can only be assigned for nodes of the
|
|
.Dq int ,
|
|
.Dq quad ,
|
|
and
|
|
.Dq string
|
|
types.
|
|
.El
|
|
.Pp
|
|
New nodes must fit the following set of criteria:
|
|
.Pp
|
|
.Bl -bullet -compact
|
|
.It
|
|
If the new node is to address an existing kernel object, only one of the
|
|
.Dq symbol
|
|
or
|
|
.Dq addr
|
|
arguments may be given.
|
|
.It
|
|
The size for a
|
|
.Dq struct
|
|
type node must be specified; no initial value is expected or permitted.
|
|
.It
|
|
Either the size or the initial value for a
|
|
.Dq string
|
|
node must be given.
|
|
.It
|
|
The node which will be the parent of the new node must be writable.
|
|
.El
|
|
.Pp
|
|
If any of the given parameters describes an invalid configuration,
|
|
.Nm
|
|
will emit a diagnostic message to the standard error and exit.
|
|
.Pp
|
|
When destroying nodes, only the path to the node is necessary, i.e.,
|
|
.Dq //destroy=old.node.path .
|
|
No other parameters are expected or permitted.
|
|
Nodes being destroyed must have no children, and their parent must be
|
|
writable.
|
|
Nodes that are marked with the
|
|
.Dq Dv PERMANENT
|
|
flag (as assigned by the kernel) may not be deleted.
|
|
.Sh FILES
|
|
.Bl -tag -width xnetinet6/udp6Xvar.hx -compact
|
|
.It Pa /etc/sysctl.conf
|
|
.Nm
|
|
variables set at boot time
|
|
.It Aq Pa sys/sysctl.h
|
|
definitions for top level identifiers, second level kernel and hardware
|
|
identifiers, and user level identifiers
|
|
.It Aq Pa sys/socket.h
|
|
definitions for second level network identifiers
|
|
.It Aq Pa sys/gmon.h
|
|
definitions for third level profiling identifiers
|
|
.It Aq Pa uvm/uvm_param.h
|
|
definitions for second level virtual memory identifiers
|
|
.It Aq Pa netinet/in.h
|
|
definitions for third level IPv4/v6 identifiers and
|
|
fourth level IPv4/v6 identifiers
|
|
.It Aq Pa netinet/icmp_var.h
|
|
definitions for fourth level ICMP identifiers
|
|
.It Aq Pa netinet/icmp6.h
|
|
definitions for fourth level ICMPv6 identifiers
|
|
.It Aq Pa netinet/tcp_var.h
|
|
definitions for fourth level TCP identifiers
|
|
.It Aq Pa netinet/udp_var.h
|
|
definitions for fourth level UDP identifiers
|
|
.It Aq Pa netinet6/udp6_var.h
|
|
definitions for fourth level IPv6 UDP identifiers
|
|
.It Aq Pa netinet6/ipsec.h
|
|
definitions for fourth level IPsec identifiers
|
|
.It Aq Pa netkey/key_var.h
|
|
definitions for third level PF_KEY identifiers
|
|
.El
|
|
.Sh EXAMPLES
|
|
For example, to retrieve the maximum number of processes allowed
|
|
in the system, one would use the following request:
|
|
.Bd -literal -offset indent -compact
|
|
sysctl kern.maxproc
|
|
.Ed
|
|
.Pp
|
|
To set the maximum number of processes allowed
|
|
in the system to 1000, one would use the following request:
|
|
.Bd -literal -offset indent -compact
|
|
sysctl -w kern.maxproc=1000
|
|
.Ed
|
|
.Pp
|
|
Information about the system clock rate may be obtained with:
|
|
.Bd -literal -offset indent -compact
|
|
sysctl kern.clockrate
|
|
.Ed
|
|
.Pp
|
|
Information about the load average history may be obtained with:
|
|
.Bd -literal -offset indent -compact
|
|
sysctl vm.loadavg
|
|
.Ed
|
|
.Pp
|
|
To view the values of the per-process variables of the current shell,
|
|
the request:
|
|
.Bd -literal -offset indent -compact
|
|
sysctl proc.$$
|
|
.Ed
|
|
can be used if the shell interpreter replaces $$ with its pid (this is true
|
|
for most shells).
|
|
.Pp
|
|
To redirect core dumps to the
|
|
.Pa /var/tmp/ Ns Aq username
|
|
directory,
|
|
.Bd -literal -offset indent -compact
|
|
sysctl -w proc.$$.corename=/var/tmp/%u/%n.core
|
|
.Ed
|
|
should be used.
|
|
.Bd -literal -offset indent -compact
|
|
sysctl -w proc.curproc.corename=/var/tmp/%u/%n.core
|
|
.Ed
|
|
changes the value for the sysctl process itself, and will not have the desired
|
|
effect.
|
|
.Pp
|
|
To create the root of a new sub-tree called
|
|
.Dq local
|
|
and then some children of that new node:
|
|
.Bd -literal -offset indent -compact
|
|
sysctl -w //create=local
|
|
sysctl -w //create=local.esm_debug,type=int,symbol=esm_debug,flags=w
|
|
sysctl -w //create=local.audiodebug,type=int,symbol=audiodebug,flags=w
|
|
.Ed
|
|
Note that the children are made writable so that the two debug
|
|
settings in question can be tuned arbitrarily.
|
|
.Pp
|
|
To destroy that same subtree:
|
|
.Bd -literal -offset indent -compact
|
|
sysctl -w //destroy=local.esm_debug
|
|
sysctl -w //destroy=local.audiodebug
|
|
sysctl -w //destroy=local
|
|
.Ed
|
|
.Sh SEE ALSO
|
|
.Xr sysctl 3 ,
|
|
.Xr ksyms 4
|
|
.Sh HISTORY
|
|
.Nm sysctl
|
|
first appeared in
|
|
.Bx 4.4 .
|