oracular (8) sysctl.8.gz

Provided by: procps_4.0.4-4ubuntu5_amd64 bug

NAME

       sysctl - configure kernel parameters at runtime

SYNOPSIS

       sysctl [options] [variable[=value]] [...]
       sysctl -p [file or regexp] [...]

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.

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

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

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

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

       -w, --write
              Force all arguments to be write arguments and print an error if they cannot be parsed this way.

       -p[FILE], --load[=FILE]
              Load  in  sysctl settings from the file specified or /etc/sysctl.conf if none given.  Specifying -
              as filename means reading data from standard input. Using  this  option  will  mean  arguments  to
              sysctl  are  files,  which  are  read  in  the order they are specified.  The file argument may be
              specified as regular expression.

       -a, --all
              Display all values currently available.

       --deprecated
              Include deprecated parameters to --all values listing.

       -b, --binary
              Print value without new line.

       --system
              Load settings from all system configuration files. See the SYSTEM FILE PRECEDENCE section below.

       -r, --pattern pattern
              Only apply settings that match pattern.  The pattern uses extended regular expression syntax.

       -A     Alias of -a

       -d     Alias of -h

       -f     Alias of -p

       -X     Alias of -a

       -o     Does nothing, exists for BSD compatibility.

       -x     Does nothing, exists for BSD compatibility.

       -h, --help
              Display help text and exit.

       -V, --version
              Display version information and exit.

SYSTEM FILE PRECEDENCE

       When using the --system option, sysctl will read files 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.

       /etc/sysctl.d/*.conf
       /run/sysctl.d/*.conf
       /usr/local/lib/sysctl.d/*.conf
       /usr/lib/sysctl.d/*.conf
       /lib/sysctl.d/*.conf
       /etc/sysctl.conf

       All configuration files are sorted in lexicographic order, regardless of the directory  they  reside  in.
       Configuration  files  can either be completely replaced (by having a new configuration file with the same
       name in a directory of higher priority) or partially replaced (by having a  configuration  file  that  is
       ordered later).

EXAMPLES

       /sbin/sysctl -a
       /sbin/sysctl -n kernel.hostname
       /sbin/sysctl -w kernel.domainname="example.com"
       /sbin/sysctl -p/etc/sysctl.conf
       /sbin/sysctl -a --pattern forward
       /sbin/sysctl -a --pattern forward$
       /sbin/sysctl -a --pattern 'net.ipv4.conf.(eth|wlan)0.arp'
       /sbin/sysctl --pattern '^net.ipv6' --system

DEPRECATED PARAMETERS

       The  base_reachable_time  and  retrans_time  are  deprecated.  The sysctl command does not allow changing
       values of these parameters.  Users who insist to use deprecated kernel interfaces should push  values  to
       /proc file system by other means.  For example:

       echo 256 > /proc/sys/net/ipv6/neigh/eth0/base_reachable_time

FILES

       /proc/sys
       /etc/sysctl.d/*.conf
       /run/sysctl.d/*.conf
       /usr/local/lib/sysctl.d/*.conf
       /usr/lib/sysctl.d/*.conf
       /lib/sysctl.d/*.conf
       /etc/sysctl.conf

SEE ALSO

       proc(5), sysctl.conf(5), regex(7)

AUTHOR

       George Staikos ⟨staikos@0wned.org

REPORTING BUGS

       Please send bug reports to ⟨procps@freelists.org