SYSCTL(8)							     SYSCTL(8)



NAME
       sysctl - configure kernel parameters at runtime

SYNOPSIS
       sysctl [-n] [-e] variable ...
       sysctl [-n] [-e] [-q] -w variable=value ...
       sysctl [-n] [-e] [-q] -p [filename]...
       sysctl [-n] [-e] [-q] --system
       sysctl [-n] [-e] -a
       sysctl [-n] [-e] -A

DESCRIPTION
       sysctl  is used to modify kernel parameters at runtime.	The parameters
       available are those listed under /proc/sys/.  Procfs  is	 required  for
       sysctl(8)  support  in  Linux.	You can use sysctl(8) to both read and
       write sysctl data.

PARAMETERS
       variable
	      The name of a key to read from.  An  example  is	kernel.ostype.
	      The '/' separator is also accepted in place of a '.'.

       variable=value
	      To set a key, use the form variable=value, where variable is the
	      key and value is the value to set it to.	If the value  contains
	      quotes or characters which are parsed by the shell, you may need
	      to enclose the value in double quotes.   This  requires  the  -w
	      parameter to use.

       -n     Use  this option to disable printing of the key name when print-
	      ing values.

       -e     Use this option to ignore errors about unknown keys.

       -N     Use this option to only print the names. It may be  useful  with
	      shells that have programmable completion.

       -q     Use this option to not display the values set to stdout.

       -w     Use this option when you want to change a sysctl setting.

       -p     Load   in	  sysctl   settings  from  the	file(s)	 specified  or
	      /etc/sysctl.conf if none given.  Specifying - as filename	 means
	      reading data from standard input.

       --system
	      Load  settings  from  all	 system configuration files. Files are
	      read from directories in the following list in given order  from
	      top  to  bottom.	Once a file of a given filename is loaded, any
	      file of the same name in subsequent directories is ignored.
	      /run/sysctl.d/*.conf
	      /etc/sysctl.d/*.conf
	      /usr/local/lib/sysctl.d/*.conf
	      /usr/lib/sysctl.d/*.conf
	      /lib/sysctl.d/*.conf
	      /etc/sysctl.conf

       -a     Display all values currently available.

       -A     Same as -a

EXAMPLES
       /sbin/sysctl -a

       /sbin/sysctl -n kernel.hostname

       /sbin/sysctl -w kernel.domainname="example.com"

       /sbin/sysctl -p /etc/sysctl.conf

NOTES
       Please note that modules loaded after sysctl is run  may	 override  the
       settings	 (example:  sunrpc.*  settings	are overridden when the sunrpc
       module is loaded). This may cause some confusion during boot  when  the
       settings	 in sysctl.conf may be overriden. To prevent such a situation,
       sysctl must be run after the particular module is  loaded  (e.g.,  from
       /etc/rc.d/rc.local or by using the install directive in modprobe.conf)

FILES
       /proc/sys /etc/sysctl.conf

SEE ALSO
       sysctl.conf(5), modprobe.conf(5)

AUTHOR
       George Staikos, <staikos@0wned.org>




				  21 Sep 1999			     SYSCTL(8)