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] -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 support in Linux. You can use sysctl 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 specified or

/etc/sysctl.conf if none given. Specifying - as filename means reading data from standard input.

-a Display all values currently available.

-A Display all values currently available in table form.

EXAMPLES

/sbin/sysctl -a
/sbin/sysctl -n kernel.hostname
/sbin/sysctl -w kernel.domainname="example.com"
/sbin/sysctl -p /etc/sysctl.conf

FILES

/proc/sys
/etc/sysctl.conf

SEE ALSO

sysctl.conf(5)

BUGS

The -A parameter behaves just as -a does.

AUTHOR

George Staikos, <staikos@0wned.org>

21 Sep 1999 SYSCTL(8)