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Diffstat (limited to 'sbin/sysctl/sysctl.8')
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diff --git a/sbin/sysctl/sysctl.8 b/sbin/sysctl/sysctl.8 new file mode 100644 index 0000000..3c20dd8 --- /dev/null +++ b/sbin/sysctl/sysctl.8 @@ -0,0 +1,242 @@ +.\" Copyright (c) 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. All advertising materials mentioning features or use of this software +.\" must display the following acknowledgement: +.\" This product includes software developed by the University of +.\" California, Berkeley and its contributors. +.\" 4. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" From: @(#)sysctl.8 8.1 (Berkeley) 6/6/93 +.\" $Id: sysctl.8,v 1.9 1996/08/23 00:56:57 mpp Exp $ +.\" +.Dd September 23, 1994 +.Dt SYSCTL 8 +.Os +.Sh NAME +.Nm sysctl +.Nd get or set kernel state +.Sh SYNOPSIS +.Nm sysctl +.Op Fl bn +.Ar name ... +.Nm sysctl +.Op Fl bn +.Fl w +.Ar name=value ... +.Nm sysctl +.Op Fl bn +.Fl aAX +.Sh DESCRIPTION +The +.Nm sysctl +utility retrieves kernel state and allows processes with +appropriate privilege to set kernel state. +The state to be retrieved or set is described using a +``Management Information Base'' (``MIB'') style name, +described as a dotted set of components. +.Pp +The +.Fl a +flag can be used to list all the currently available string or integer values. +.Pp +The +.Fl A +flag will list all the known MIB names including opaques. +Those with string or integer values will be printed as with the +.Fl a +flag; for the opaque values, +information about the format and the length is printed in addition the first +few bytes is dumped in hex. +.Pp +The +.Fl X +flag is the same as +.Fl A +except the entire value of opaque variables is hexdumped. +.Pp +The +.Fl n +flag specifies that the printing of the field name should be +suppressed and that only its value should be output. +This flag is useful for setting shell variables. +For example, to save the pagesize in variable psize, use: +.Bd -literal -offset indent -compact +set psize=`sysctl -n hw.pagesize` +.Ed +.Pp +The +.Fl b +flag forces the value of the variable(s) to be output in raw, binary +format. No names are printed and no terminating newlines are output. +This is mostly useful with a single variable. +.Pp +If just a MIB style name is given, +the corresponding value is retrieved. +If a value is to be set, the +.Fl w +flag must be specified and the MIB name followed +by an equal sign and the new value to be used. +.Pp +The information available from +.Nm sysctl +consists of integers, strings, and opaques. +.Nm sysctl +only knows about a couple of opaque types, and will resort to hexdumps +for the rest. +The opaque information is much more useful if retrieved by special +purpose programs such as +.Nm ps , +.Nm systat , +and +.Nm netstat . +.Pp +The string and integer information is summarized below. +For a detailed description of these variable see +.Xr sysctl 3 . +.Pp +The changeable column indicates whether a process with appropriate +privilege can change the value. +.Bl -column net.inet.ip.forwardingxxxxxx integerxxx +.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 yes +.It kern.maxprocperuid integer yes +.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 +.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.update integer yes +.It kern.osreldate string no +.It kern.bootfile string 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 machdep.console_device dev_t no +.It machdep.adjkerntz integer yes +.It machdep.disable_rtc_set integer yes +.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 +.El +.Sh EXAMPLES +.Pp +For example, to retrieve the maximum number of processes allowed +in the system, one would use the follow 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 follow 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 +More variables than these exist, and the best and likely only place +to search for their deeper meaning is undoubtedly the source where +they are defined. +.Sh FILES +.Bl -tag -width <netinet/icmpXvar.h> -compact +.It Pa <sys/sysctl.h> +definitions for top level identifiers, second level kernel and hardware +identifiers, and user level identifiers +.It Pa <sys/socket.h> +definitions for second level network identifiers +.It Pa <sys/gmon.h> +definitions for third level profiling identifiers +.It Pa <vm/vm_param.h> +definitions for second level virtual memory identifiers +.It Pa <netinet/in.h> +definitions for third level Internet identifiers and +fourth level IP identifiers +.It Pa <netinet/icmp_var.h> +definitions for fourth level ICMP identifiers +.It Pa <netinet/udp_var.h> +definitions for fourth level UDP identifiers +.El +.Sh SEE ALSO +.Xr sysctl 3 +.Sh BUGS +.Nm sysctl +presently exploits an undocumented interface to the kernel +sysctl facility to traverse the sysctl tree and to retrieve format +and name information. +This correct interface is being thought about for the time being. +.Sh HISTORY +.Nm sysctl +first appeared in +.Bx 4.4 . +.Pp +In +.Fx 2.2 +.Nm sysctl +was significantly remodeled. |
