Skip site navigation (1)Skip section navigation (2)

FreeBSD Man Pages

Man Page or Keyword Search:
Man Architecture
Apropos Keyword Search (all sections) Output format
home | help
SYSRC(8)		FreeBSD	System Manager's Manual		      SYSRC(8)

NAME
     sysrc -- safely edit system rc files

SYNOPSIS
     sysrc [-cdDeFhinNqvx] [-f file] [-j jail |	-R dir]	name[=value] ...
     sysrc [-cdDeFhinNqvx] [-f file] [-j jail |	-R dir]	-a | -A

DESCRIPTION
     The sysrc utility retrieves rc.conf(5) variables from the collection of
     system rc files and allows	processes with appropriate privilege to	change
     values in a safe and effective manner.

     The following options are available:

     -a	      Dump a list of all non-default configuration variables.

     -A	      Dump a list of all configuration variables (incl.	defaults).

     -c	      Check only.  For querying, return	success	if all requested vari-
	      ables are	set (even if NULL), otherwise return error status.
	      For assignments, return success if no changes are	required, oth-
	      erwise failure.  If verbose (see ``-v'') prints a	message	stat-
	      ing whether variables are	set and/or changes are required.

     -d	      Print a description of the given variable.

     -D	      Show default value(s) only (this is the same as setting RC_CONFS
	      to NULL or passing `-f' with a NULL file-argument).

     -e	      Print query results as sh(1) compatible syntax (for example,
	      `var=value').  Ignored if	either `-n' or `-F' is specified.

     -f	file  Operate on the specified file(s) instead of the files obtained
	      by reading the `rc_conf_files' entry in the RC_DEFAULTS file.
	      This option can be specified multiple times for additional
	      files.

     -F	      Show only	the last rc.conf(5) file each directive	is in.

     -h	      Print a short usage message to stderr and	exit.

     --help   Print a full usage statement to stderr and exit.

     -i	      Ignore unknown variables.

     -j	jail  The jid or name of the jail to operate within (overrides `-R
	      dir'; requires jexec(8)).

     -n	      Show only	variable values, not their names.

     -N	      Show only	variable names,	not their values.

     -q	      Quiet.  Disable verbose and hide certain errors.

     -R	dir   Operate within the root directory	`dir' rather than `/'.

     -v	      Verbose.	Print the pathname of the specific rc.conf(5) file
	      where the	directive was found.

     --version
	      Print version information	to stdout and exit.

     -x	      Remove variable(s) from specified	file(s).

     This utility has a	similar	syntax to sysctl(8).  It shares	the `-e' and
     `-n' options (detailed above) and also has	the same `name[=value]'	syntax
     for making	queries/assignments.

     However, while sysctl(8) serves to	query/modify MIBs in the entrant ker-
     nel, sysrc	instead	works on values	in the system rc.conf(5) configuration
     files.

     The list of system	configuration files is configured in the file
     `/etc/defaults/rc.conf' within the	variable `rc_conf_files', which	by-
     default contains a	space-separated	list of	pathnames.  On all FreeBSD
     systems, this defaults to the value "/etc/rc.conf /etc/rc.conf.local".
     Each pathname is sourced in-order upon startup.  It is in the same	fash-
     ion that sysrc sources the	configuration files before returning the value
     of	the given variable.

     When supplied a variable name, sysrc will return the value	of the vari-
     able.  If the variable does not appear in any of the configured
     `rc_conf_files', an error is printed and error status is returned.

     When changing values of a given variable, it does not matter if the vari-
     able appears in any of the	`rc_conf_files'	or not.	 If the	variable does
     not appear	in any of the files, it	is appended to the end of the first
     pathname in the `rc_conf_files' variable.	Otherwise, sysrc will replace
     only the last-occurrence in the last-file found to	contain	the variable.
     This gets the value to take effect	next boot without heavily modifying
     these integral files (yet taking care not to allow	the file to grow
     unwieldy should sysrc be called repeatedly).

ENVIRONMENT
     The following environment variables are referenced	by sysrc:

     RC_CONFS	  Override default `rc_conf_files' (even if set	to NULL).

     RC_DEFAULTS  Location of `/etc/defaults/rc.conf' file.

DEPENDENCIES
     The following standard commands are required by sysrc:

     awk(1), cat(1), chmod(1), env(1), grep(1),	jls(1),	mktemp(1), mv(1),
     rm(1), sh(1), stat(1), tail(1), chown(8) and jexec(8).

FILES
     /etc/defaults/rc.conf
     /etc/rc.conf
     /etc/rc.conf.local

EXAMPLES
     Below are some simple examples of how sysrc can be	used to	query certain
     values from the rc.conf(5)	collection of system configuration files:

     sysrc sshd_enable
	   returns the value of	$sshd_enable, usually YES or NO.

     sysrc defaultrouter
	   returns IP address of default router	(if configured).

     Working on	other files, such as crontab(5):

     sysrc -f /etc/crontab MAILTO
	   returns the value of	the MAILTO setting (if configured).

     In	addition to the	above syntax, sysrc also supports inline sh(1) PARAME-
     TER expansion for changing	the way	values are reported, shown below:

     sysrc 'hostname%%.*'
	   returns $hostname up	to (but	not including) first `.'.

     sysrc 'network_interfaces%%[$IFS]*'
	   returns first word of $network_interfaces.

     sysrc 'ntpdate_flags##*[$IFS]'
	   returns last	word of	$ntpdate_flags (time server address).

     sysrc usbd_flags-"default"
	   returns $usbd_flags or default if unset or NULL.

     sysrc cloned_interfaces+"alternate"
	   returns alternate if	$cloned_interfaces is set.

     sysrc '#kern_securelevel'
	   returns length in characters	of $kern_securelevel.

     sysrc 'hostname?'
	   returns NULL	and error status 2 if $hostname	is unset (or if	set,
	   returns the value of	$hostname with no error	status).

     sysrc 'hostname:?'
	   returns NULL	and error status 2 if $hostname	is unset or NULL (or
	   if set and non-NULL,	returns	value without error status).

LIMITATIONS
     The sysrc utility presently does not support the `rc.conf.d' collection
     of	system configuration files (which requires a service name to be	known
     during execution).

     This will be corrected by a future	enhancement.

SEE ALSO
     jls(1), rc.conf(5), jail(8), jexec(8), rc(8), sysctl(8)

HISTORY
     A sysrc utility first appeared in FreeBSD 9.2.

AUTHORS
     Devin Teske <dteske@FreeBSD.org>

THANKS TO
     Brandon Gooch, Garrett Cooper, Julian Elischer, Pawel Jakub Dawidek,
     Cyrille Lefevre, Ross West, Stefan	Esser, Marco Steinbach,	Jilles
     Tjoelker, Allan Jude, and Lars Engels for suggestions, help, and testing.

FreeBSD	10.1			 Jul 18, 2014			  FreeBSD 10.1

NAME | SYNOPSIS | DESCRIPTION | ENVIRONMENT | DEPENDENCIES | FILES | EXAMPLES | LIMITATIONS | SEE ALSO | HISTORY | AUTHORS | THANKS TO

Want to link to this manual page? Use this URL:
<http://www.freebsd.org/cgi/man.cgi?query=sysrc&sektion=8&manpath=FreeBSD+10.1-RELEASE>

home | help