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VISUDO(8)		  BSD System Manager's Manual		     VISUDO(8)

     visudo -- edit the	sudoers	file

     visudo [-chqsV] [-f sudoers] [-x output_file]

     visudo edits the sudoers file in a	safe fashion, analogous	to vipw(8).
     visudo locks the sudoers file against multiple simultaneous edits,	pro-
     vides basic sanity	checks,	and checks for parse errors.  If the sudoers
     file is currently being edited you	will receive a message to try again

     There is a	hard-coded list	of one or more editors that visudo will	use
     set at compile-time that may be overridden	via the	editor sudoers Default
     variable.	This list defaults to vi.  Normally, visudo does not honor the
     VISUAL or EDITOR environment variables unless they	contain	an editor in
     the aforementioned	editors	list.  However,	if visudo is configured	with
     the --with-env-editor option or the env_editor Default variable is	set in
     sudoers, visudo will use any the editor defines by	VISUAL or EDITOR.
     Note that this can	be a security hole since it allows the user to execute
     any program they wish simply by setting VISUAL or EDITOR.

     visudo parses the sudoers file after the edit and will not	save the
     changes if	there is a syntax error.  Upon finding an error, visudo	will
     print a message stating the line number(s)	where the error	occurred and
     the user will receive the "What now?" prompt.  At this point the user may
     enter `e' to re-edit the sudoers file, `x'	to exit	without	saving the
     changes, or `Q' to	quit and save changes.	The `Q'	option should be used
     with extreme care because if visudo believes there	to be a	parse error,
     so	will sudo and no one will be able to run sudo again until the error is
     fixed.  If	`e' is typed to	edit the sudoers file after a parse error has
     been detected, the	cursor will be placed on the line where	the error oc-
     curred (if	the editor supports this feature).

     The options are as	follows:

     -c, --check
		 Enable	check-only mode.  The existing sudoers file will be
		 checked for syntax errors, owner and mode.  A message will be
		 printed to the	standard output	describing the status of
		 sudoers unless	the -q option was specified.  If the check
		 completes successfully, visudo	will exit with a value of 0.
		 If an error is	encountered, visudo will exit with a value of

     -f	sudoers, --file=sudoers
		 Specify an alternate sudoers file location.  With this	op-
		 tion, visudo will edit	(or check) the sudoers file of your
		 choice, instead of the	default, /usr/local/etc/sudoers.  The
		 lock file used	is the specified sudoers file with ".tmp" ap-
		 pended	to it.	In check-only mode only, the argument to -f
		 may be	`-', indicating	that sudoers will be read from the
		 standard input.

     -h, --help	 Display a short help message to the standard output and exit.

     -q, --quiet
		 Enable	quiet mode.  In	this mode details about	syntax errors
		 are not printed.  This	option is only useful when combined
		 with the -c option.

     -s, --strict
		 Enable	strict checking	of the sudoers file.  If an alias is
		 referenced but	not actually defined or	if there is a cycle in
		 an alias, visudo will consider	this a parse error.  Note that
		 it is not possible to differentiate between an	alias and a
		 host name or user name	that consists solely of	uppercase let-
		 ters, digits, and the underscore (`_')	character.

     -V, --version
		 Print the visudo and sudoers grammar versions and exit.

     -x	output_file, --export=output_file
		 Export	a sudoers in JSON format and write it to output_file.
		 If output_file	is `-',	the exported sudoers policy will be
		 written to the	standard output.  By default,
		 /usr/local/etc/sudoers	(and any files it includes) will be
		 exported.  The	-f option can be used to specify a different
		 sudoers file to export.  The exported format is intended to
		 be easier for third-party applications	to parse than the tra-
		 ditional sudoers format.  The various values have explicit
		 types which removes much of the ambiguity of the sudoers for-

   Debugging and sudoers plugin	arguments
     visudo versions 1.8.4 and higher support a	flexible debugging framework
     that is configured	via Debug lines	in the sudo.conf(5) file.

     Starting with sudo	1.8.12,	visudo will also parse the arguments to	the
     sudoers plugin to override	the default sudoers path name, UID, GID	and
     file mode.	 These arguments, if present, should be	listed after the path
     to	the plugin (i.e. after  Multiple arguments	may be speci-
     fied, separated by	white space.  For example:

	   Plugin sudoers_policy sudoers_mode=0400

     The following arguments are supported:

	       The sudoers_file	argument can be	used to	override the default
	       path to the sudoers file.

	       The sudoers_uid argument	can be used to override	the default
	       owner of	the sudoers file.  It should be	specified as a numeric
	       user ID.

	       The sudoers_gid argument	can be used to override	the default
	       group of	the sudoers file.  It must be specified	as a numeric
	       group ID	(not a group name).

	       The sudoers_mode	argument can be	used to	override the default
	       file mode for the sudoers file.	It should be specified as an
	       octal value.

     For more information on configuring sudo.conf(5), please refer to its

     The following environment variables may be	consulted depending on the
     value of the editor and env_editor	sudoers	settings:

     VISUAL	      Invoked by visudo	as the editor to use

     EDITOR	      Used by visudo if	VISUAL is not set

     /usr/local/etc/sudo.conf  Sudo front end configuration

     /usr/local/etc/sudoers    List of who can run what

			       Lock file for visudo

     In	addition to reporting sudoers parse errors, visudo may produce the
     following messages:

     sudoers file busy,	try again later.
	   Someone else	is currently editing the sudoers file.

     /usr/local/etc/sudoers.tmp: Permission denied
	   You didn't run visudo as root.

     you do not	exist in the passwd database
	   Your	user ID	does not appear	in the system passwd database.

     Warning: {User,Runas,Host,Cmnd}_Alias referenced but not defined
	   Either you are trying to use	an undeclared
	   {User,Runas,Host,Cmnd}_Alias	or you have a user or host name	listed
	   that	consists solely	of uppercase letters, digits, and the under-
	   score (`_') character.  In the latter case, you can ignore the
	   warnings (sudo will not complain).  The message is prefixed with
	   the path name of the	sudoers	file and the line number where the un-
	   defined alias was used.  In -s (strict) mode	these are errors, not

     Warning: unused {User,Runas,Host,Cmnd}_Alias
	   The specified {User,Runas,Host,Cmnd}_Alias was defined but never
	   used.  The message is prefixed with the path	name of	the sudoers
	   file	and the	line number where the unused alias was defined.	 You
	   may wish to comment out or remove the unused	alias.

     Warning: cycle in {User,Runas,Host,Cmnd}_Alias
	   The specified {User,Runas,Host,Cmnd}_Alias includes a reference to
	   itself, either directly or through an alias it includes.  The mes-
	   sage	is prefixed with the path name of the sudoers file and the
	   line	number where the cycle was detected.  This is only a warning
	   unless visudo is run	in -s (strict) mode as sudo will ignore	cycles
	   when	parsing	the sudoers file.

     unknown defaults entry "name"
	   The sudoers file contains a Defaults	setting	not recognized by

     /usr/local/etc/sudoers: input and output files must be different
	   The -x flag was used	and the	specified output_file has the same
	   path	name as	the sudoers file to export.

     vi(1), sudo.conf(5), sudoers(5), sudo(8), vipw(8)

     Many people have worked on	sudo over the years; this version consists of
     code written primarily by:

	   Todd	C. Miller

     See the CONTRIBUTORS file in the sudo distribution
     ( for an exhaustive list of people
     who have contributed to sudo.

     There is no easy way to prevent a user from gaining a root	shell if the
     editor used by visudo allows shell	escapes.

     If	you feel you have found	a bug in visudo, please	submit a bug report at

     Limited free support is available via the sudo-users mailing list,	see to	subscribe or search
     the archives.

     visudo is provided	"AS IS"	and any	express	or implied warranties, includ-
     ing, but not limited to, the implied warranties of	merchantability	and
     fitness for a particular purpose are disclaimed.  See the LICENSE file
     distributed with sudo or for complete

Sudo 1.8.20p2		       February	22, 2017		 Sudo 1.8.20p2


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