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SUDOERS(5)		    BSD File Formats Manual		    SUDOERS(5)

NAME
     sudoers -- default sudo security policy module

DESCRIPTION
     The sudoers policy module determines a user's sudo privileges.  It is the
     default sudo policy plugin.  The policy is driven by the /etc/sudoers
     file or, optionally in LDAP.  The policy format is described in detail in
     the SUDOERS FILE FORMAT section.  For information on storing sudoers pol-
     icy information in LDAP, please see sudoers.ldap(5).

   Authentication and logging
     The sudoers security policy requires that most users authenticate them-
     selves before they can use sudo.  A password is not required if the
     invoking user is root, if the target user is the same as the invoking
     user, or if the policy has disabled authentication for the user or com-
     mand.  Unlike su(1), when sudoers requires authentication, it validates
     the invoking user's credentials, not the target user's (or root's) cre-
     dentials.	This can be changed via the rootpw, targetpw and runaspw
     flags, described later.

     If a user who is not listed in the policy tries to run a command via
     sudo, mail is sent to the proper authorities.  The address used for such
     mail is configurable via the mailto Defaults entry (described later) and
     defaults to root.

     Note that mail will not be sent if an unauthorized user tries to run sudo
     with the -l or -v option.	This allows users to determine for themselves
     whether or not they are allowed to use sudo.

     If sudo is run by root and the SUDO_USER environment variable is set, the
     sudoers policy will use this value to determine who the actual user is.
     This can be used by a user to log commands through sudo even when a root
     shell has been invoked.  It also allows the -e option to remain useful
     even when invoked via a sudo-run script or program.  Note, however, that
     the sudoers lookup is still done for root, not the user specified by
     SUDO_USER.

     sudoers uses time stamp files for credential caching.  Once a user has
     been authenticated, the time stamp is updated and the user may then use
     sudo without a password for a short period of time (5 minutes unless
     overridden by the timeout option).	 By default, sudoers uses a tty-based
     time stamp which means that there is a separate time stamp for each of a
     user's login sessions.  The tty_tickets option can be disabled to force
     the use of a single time stamp for all of a user's sessions.

     sudoers can log both successful and unsuccessful attempts (as well as
     errors) to syslog(3), a log file, or both.	 By default, sudoers will log
     via syslog(3) but this is changeable via the syslog and logfile Defaults
     settings.

     sudoers also supports logging a command's input and output streams.  I/O
     logging is not on by default but can be enabled using the log_input and
     log_output Defaults flags as well as the LOG_INPUT and LOG_OUTPUT command
     tags.

   Command environment
     Since environment variables can influence program behavior, sudoers pro-
     vides a means to restrict which variables from the user's environment are
     inherited by the command to be run.  There are two distinct ways sudoers
     can deal with environment variables.

     By default, the env_reset option is enabled.  This causes commands to be
     executed with a new, minimal environment.	On AIX (and Linux systems
     without PAM), the environment is initialized with the contents of the
     /etc/environment file.  The new environment contains the TERM, PATH,
     HOME, MAIL, SHELL, LOGNAME, USER, USERNAME and SUDO_* variables in addi-
     tion to variables from the invoking process permitted by the env_check
     and env_keep options.  This is effectively a whitelist for environment
     variables.

     If, however, the env_reset option is disabled, any variables not explic-
     itly denied by the env_check and env_delete options are inherited from
     the invoking process.  In this case, env_check and env_delete behave like
     a blacklist.  Since it is not possible to blacklist all potentially dan-
     gerous environment variables, use of the default env_reset behavior is
     encouraged.

     In all cases, environment variables with a value beginning with () are
     removed as they could be interpreted as bash functions.  The list of
     environment variables that sudo allows or denies is contained in the out-
     put of ``sudo -V'' when run as root.

     Note that the dynamic linker on most operating systems will remove vari-
     ables that can control dynamic linking from the environment of setuid
     executables, including sudo.  Depending on the operating system this may
     include _RLD*, DYLD_*, LD_*, LDR_*, LIBPATH, SHLIB_PATH, and others.
     These type of variables are removed from the environment before sudo even
     begins execution and, as such, it is not possible for sudo to preserve
     them.

     As a special case, if sudo's -i option (initial login) is specified,
     sudoers will initialize the environment regardless of the value of
     env_reset.	 The DISPLAY, PATH and TERM variables remain unchanged; HOME,
     MAIL, SHELL, USER, and LOGNAME are set based on the target user.  On AIX
     (and Linux systems without PAM), the contents of /etc/environment are
     also included.  All other environment variables are removed.

     Finally, if the env_file option is defined, any variables present in that
     file will be set to their specified values as long as they would not con-
     flict with an existing environment variable.

SUDOERS FILE FORMAT
     The sudoers file is composed of two types of entries: aliases (basically
     variables) and user specifications (which specify who may run what).

     When multiple entries match for a user, they are applied in order.	 Where
     there are multiple matches, the last match is used (which is not neces-
     sarily the most specific match).

     The sudoers grammar will be described below in Extended Backus-Naur Form
     (EBNF).  Don't despair if you are unfamiliar with EBNF; it is fairly sim-
     ple, and the definitions below are annotated.

   Quick guide to EBNF
     EBNF is a concise and exact way of describing the grammar of a language.
     Each EBNF definition is made up of production rules.  E.g.,

     symbol ::= definition | alternate1 | alternate2 ...

     Each production rule references others and thus makes up a grammar for
     the language.  EBNF also contains the following operators, which many
     readers will recognize from regular expressions.  Do not, however, con-
     fuse them with ``wildcard'' characters, which have different meanings.

     ?	   Means that the preceding symbol (or group of symbols) is optional.
	   That is, it may appear once or not at all.

     *	   Means that the preceding symbol (or group of symbols) may appear
	   zero or more times.

     +	   Means that the preceding symbol (or group of symbols) may appear
	   one or more times.

     Parentheses may be used to group symbols together.	 For clarity, we will
     use single quotes ('') to designate what is a verbatim character string
     (as opposed to a symbol name).

   Aliases
     There are four kinds of aliases: User_Alias, Runas_Alias, Host_Alias and
     Cmnd_Alias.

     Alias ::= 'User_Alias'  User_Alias (':' User_Alias)* |
	       'Runas_Alias' Runas_Alias (':' Runas_Alias)* |
	       'Host_Alias'  Host_Alias (':' Host_Alias)* |
	       'Cmnd_Alias'  Cmnd_Alias (':' Cmnd_Alias)*

     User_Alias ::= NAME '=' User_List

     Runas_Alias ::= NAME '=' Runas_List

     Host_Alias ::= NAME '=' Host_List

     Cmnd_Alias ::= NAME '=' Cmnd_List

     NAME ::= [A-Z]([A-Z][0-9]_)*

     Each alias definition is of the form

     Alias_Type NAME = item1, item2, ...

     where Alias_Type is one of User_Alias, Runas_Alias, Host_Alias, or
     Cmnd_Alias.  A NAME is a string of uppercase letters, numbers, and under-
     score characters (`_').  A NAME must start with an uppercase letter.  It
     is possible to put several alias definitions of the same type on a single
     line, joined by a colon (`:').  E.g.,

     Alias_Type NAME = item1, item2, item3 : NAME = item4, item5

     The definitions of what constitutes a valid alias member follow.

     User_List ::= User |
		   User ',' User_List

     User ::= '!'* user name |
	      '!'* #uid |
	      '!'* %group |
	      '!'* %#gid |
	      '!'* +netgroup |
	      '!'* %:nonunix_group |
	      '!'* %:#nonunix_gid |
	      '!'* User_Alias

     A User_List is made up of one or more user names, user ids (prefixed with
     `#'), system group names and ids (prefixed with `%' and `%#' respec-
     tively), netgroups (prefixed with `+'), non-Unix group names and IDs
     (prefixed with `%:' and `%:#' respectively) and User_Aliases. Each list
     item may be prefixed with zero or more `!' operators.  An odd number of
     `!' operators negate the value of the item; an even number just cancel
     each other out.

     A user name, uid, group, gid, netgroup, nonunix_group or nonunix_gid may
     be enclosed in double quotes to avoid the need for escaping special char-
     acters.  Alternately, special characters may be specified in escaped hex
     mode, e.g. \x20 for space.	 When using double quotes, any prefix charac-
     ters must be included inside the quotes.

     The actual nonunix_group and nonunix_gid syntax depends on the underlying
     group provider plugin (see the group_plugin description below).  For
     instance, the QAS AD plugin supports the following formats:

     o	   Group in the same domain: "%:Group Name"

     o	   Group in any domain: "%:Group Name@FULLY.QUALIFIED.DOMAIN"

     o	   Group SID: "%:S-1-2-34-5678901234-5678901234-5678901234-567"

     Note that quotes around group names are optional.	Unquoted strings must
     use a backslash (`\') to escape spaces and special characters.  See Other
     special characters and reserved words for a list of characters that need
     to be escaped.

     Runas_List ::= Runas_Member |
		    Runas_Member ',' Runas_List

     Runas_Member ::= '!'* user name |
		      '!'* #uid |
		      '!'* %group |
		      '!'* %#gid |
		      '!'* %:nonunix_group |
		      '!'* %:#nonunix_gid |
		      '!'* +netgroup |
		      '!'* Runas_Alias

     A Runas_List is similar to a User_List except that instead of
     User_Aliases it can contain Runas_Aliases.	 Note that user names and
     groups are matched as strings.  In other words, two users (groups) with
     the same uid (gid) are considered to be distinct.	If you wish to match
     all user names with the same uid (e.g. root and toor), you can use a uid
     instead (#0 in the example given).

     Host_List ::= Host |
		   Host ',' Host_List

     Host ::= '!'* host name |
	      '!'* ip_addr |
	      '!'* network(/netmask)? |
	      '!'* +netgroup |
	      '!'* Host_Alias

     A Host_List is made up of one or more host names, IP addresses, network
     numbers, netgroups (prefixed with `+') and other aliases.	Again, the
     value of an item may be negated with the `!' operator.  If you do not
     specify a netmask along with the network number, sudo will query each of
     the local host's network interfaces and, if the network number corre-
     sponds to one of the hosts's network interfaces, the corresponding net-
     mask will be used.	 The netmask may be specified either in standard IP
     address notation (e.g. 255.255.255.0 or ffff:ffff:ffff:ffff::), or CIDR
     notation (number of bits, e.g. 24 or 64).	A host name may include shell-
     style wildcards (see the Wildcards section below), but unless the host
     name command on your machine returns the fully qualified host name,
     you'll need to use the fqdn option for wildcards to be useful.  Note that
     sudo only inspects actual network interfaces; this means that IP address
     127.0.0.1 (localhost) will never match.  Also, the host name
     ``localhost'' will only match if that is the actual host name, which is
     usually only the case for non-networked systems.

     Cmnd_List ::= Cmnd |
		   Cmnd ',' Cmnd_List

     command name ::= file name |
		      file name args |
		      file name '""'

     Cmnd ::= '!'* command name |
	      '!'* directory |
	      '!'* "sudoedit" |
	      '!'* Cmnd_Alias

     A Cmnd_List is a list of one or more command names, directories, and
     other aliases.  A command name is a fully qualified file name which may
     include shell-style wildcards (see the Wildcards section below).  A sim-
     ple file name allows the user to run the command with any arguments
     he/she wishes.  However, you may also specify command line arguments
     (including wildcards).  Alternately, you can specify "" to indicate that
     the command may only be run without command line arguments.  A directory
     is a fully qualified path name ending in a `/'.  When you specify a
     directory in a Cmnd_List, the user will be able to run any file within
     that directory (but not in any sub-directories therein).

     If a Cmnd has associated command line arguments, then the arguments in
     the Cmnd must match exactly those given by the user on the command line
     (or match the wildcards if there are any).	 Note that the following char-
     acters must be escaped with a `\' if they are used in command arguments:
     `,', `:', `=', `\'.  The special command ``sudoedit'' is used to permit a
     user to run sudo with the -e option (or as sudoedit).  It may take com-
     mand line arguments just as a normal command does.

   Defaults
     Certain configuration options may be changed from their default values at
     run-time via one or more Default_Entry lines.  These may affect all users
     on any host, all users on a specific host, a specific user, a specific
     command, or commands being run as a specific user.	 Note that per-command
     entries may not include command line arguments.  If you need to specify
     arguments, define a Cmnd_Alias and reference that instead.

     Default_Type ::= 'Defaults' |
		      'Defaults' '@' Host_List |
		      'Defaults' ':' User_List |
		      'Defaults' '!' Cmnd_List |
		      'Defaults' '>' Runas_List

     Default_Entry ::= Default_Type Parameter_List

     Parameter_List ::= Parameter |
			Parameter ',' Parameter_List

     Parameter ::= Parameter '=' Value |
		   Parameter '+=' Value |
		   Parameter '-=' Value |
		   '!'* Parameter

     Parameters may be flags, integer values, strings, or lists.  Flags are
     implicitly boolean and can be turned off via the `!' operator.  Some
     integer, string and list parameters may also be used in a boolean context
     to disable them.  Values may be enclosed in double quotes ("") when they
     contain multiple words.  Special characters may be escaped with a back-
     slash (`\').

     Lists have two additional assignment operators, += and -=.	 These opera-
     tors are used to add to and delete from a list respectively.  It is not
     an error to use the -= operator to remove an element that does not exist
     in a list.

     Defaults entries are parsed in the following order: generic, host and
     user Defaults first, then runas Defaults and finally command defaults.

     See SUDOERS OPTIONS for a list of supported Defaults parameters.

   User specification
     User_Spec ::= User_List Host_List '=' Cmnd_Spec_List \
		   (':' Host_List '=' Cmnd_Spec_List)*

     Cmnd_Spec_List ::= Cmnd_Spec |
			Cmnd_Spec ',' Cmnd_Spec_List

     Cmnd_Spec ::= Runas_Spec? SELinux_Spec? Tag_Spec* Cmnd

     Runas_Spec ::= '(' Runas_List? (':' Runas_List)? ')'

     SELinux_Spec ::= ('ROLE=role' | 'TYPE=type')

     Tag_Spec ::= ('NOPASSWD:' | 'PASSWD:' | 'NOEXEC:' | 'EXEC:' |
		   'SETENV:' | 'NOSETENV:' | 'LOG_INPUT:' | 'NOLOG_INPUT:' |
		   'LOG_OUTPUT:' | 'NOLOG_OUTPUT:')

     A user specification determines which commands a user may run (and as
     what user) on specified hosts.  By default, commands are run as root, but
     this can be changed on a per-command basis.

     The basic structure of a user specification is ``who where = (as_whom)
     what''.  Let's break that down into its constituent parts:

   Runas_Spec
     A Runas_Spec determines the user and/or the group that a command may be
     run as.  A fully-specified Runas_Spec consists of two Runas_Lists (as
     defined above) separated by a colon (`:') and enclosed in a set of paren-
     theses.  The first Runas_List indicates which users the command may be
     run as via sudo's -u option.  The second defines a list of groups that
     can be specified via sudo's -g option.  If both Runas_Lists are speci-
     fied, the command may be run with any combination of users and groups
     listed in their respective Runas_Lists. If only the first is specified,
     the command may be run as any user in the list but no -g option may be
     specified.	 If the first Runas_List is empty but the second is specified,
     the command may be run as the invoking user with the group set to any
     listed in the Runas_List.	If both Runas_Lists are empty, the command may
     only be run as the invoking user.	If no Runas_Spec is specified the com-
     mand may be run as root and no group may be specified.

     A Runas_Spec sets the default for the commands that follow it.  What this
     means is that for the entry:

     dgb     boulder = (operator) /bin/ls, /bin/kill, /usr/bin/lprm

     The user dgb may run /bin/ls, /bin/kill, and /usr/bin/lprm--but only as
     operator.	E.g.,

     $ sudo -u operator /bin/ls

     It is also possible to override a Runas_Spec later on in an entry.	 If we
     modify the entry like so:

     dgb     boulder = (operator) /bin/ls, (root) /bin/kill, /usr/bin/lprm

     Then user dgb is now allowed to run /bin/ls as operator, but /bin/kill
     and /usr/bin/lprm as root.

     We can extend this to allow dgb to run /bin/ls with either the user or
     group set to operator:

     dgb     boulder = (operator : operator) /bin/ls, (root) /bin/kill,\
	     /usr/bin/lprm

     Note that while the group portion of the Runas_Spec permits the user to
     run as command with that group, it does not force the user to do so.  If
     no group is specified on the command line, the command will run with the
     group listed in the target user's password database entry.	 The following
     would all be permitted by the sudoers entry above:

     $ sudo -u operator /bin/ls
     $ sudo -u operator -g operator /bin/ls
     $ sudo -g operator /bin/ls

     In the following example, user tcm may run commands that access a modem
     device file with the dialer group.

     tcm     boulder = (:dialer) /usr/bin/tip, /usr/bin/cu,\
	     /usr/local/bin/minicom

     Note that in this example only the group will be set, the command still
     runs as user tcm.	E.g.

     $ sudo -g dialer /usr/bin/cu

     Multiple users and groups may be present in a Runas_Spec, in which case
     the user may select any combination of users and groups via the -u and -g
     options.  In this example:

     alan    ALL = (root, bin : operator, system) ALL

     user alan may run any command as either user root or bin, optionally set-
     ting the group to operator or system.

   SELinux_Spec
     On systems with SELinux support, sudoers entries may optionally have an
     SELinux role and/or type associated with a command.  If a role or type is
     specified with the command it will override any default values specified
     in sudoers.  A role or type specified on the command line, however, will
     supersede the values in sudoers.

   Tag_Spec
     A command may have zero or more tags associated with it.  There are ten
     possible tag values: NOPASSWD, PASSWD, NOEXEC, EXEC, SETENV, NOSETENV,
     LOG_INPUT, NOLOG_INPUT, LOG_OUTPUT and NOLOG_OUTPUT.  Once a tag is set
     on a Cmnd, subsequent Cmnds in the Cmnd_Spec_List, inherit the tag unless
     it is overridden by the opposite tag (in other words, PASSWD overrides
     NOPASSWD and NOEXEC overrides EXEC).

     NOPASSWD and PASSWD

     By default, sudo requires that a user authenticate him or herself before
     running a command.	 This behavior can be modified via the NOPASSWD tag.
     Like a Runas_Spec, the NOPASSWD tag sets a default for the commands that
     follow it in the Cmnd_Spec_List.  Conversely, the PASSWD tag can be used
     to reverse things.	 For example:

     ray     rushmore = NOPASSWD: /bin/kill, /bin/ls, /usr/bin/lprm

     would allow the user ray to run /bin/kill, /bin/ls, and /usr/bin/lprm as
     root on the machine rushmore without authenticating himself.  If we only
     want ray to be able to run /bin/kill without a password the entry would
     be:

     ray     rushmore = NOPASSWD: /bin/kill, PASSWD: /bin/ls, /usr/bin/lprm

     Note, however, that the PASSWD tag has no effect on users who are in the
     group specified by the exempt_group option.

     By default, if the NOPASSWD tag is applied to any of the entries for a
     user on the current host, he or she will be able to run ``sudo -l'' with-
     out a password.  Additionally, a user may only run ``sudo -v'' without a
     password if the NOPASSWD tag is present for all a user's entries that
     pertain to the current host.  This behavior may be overridden via the
     verifypw and listpw options.

     NOEXEC and EXEC

     If sudo has been compiled with noexec support and the underlying operat-
     ing system supports it, the NOEXEC tag can be used to prevent a dynami-
     cally-linked executable from running further commands itself.

     In the following example, user aaron may run /usr/bin/more and
     /usr/bin/vi but shell escapes will be disabled.

     aaron   shanty = NOEXEC: /usr/bin/more, /usr/bin/vi

     See the Preventing shell escapes section below for more details on how
     NOEXEC works and whether or not it will work on your system.

     SETENV and NOSETENV

     These tags override the value of the setenv option on a per-command
     basis.  Note that if SETENV has been set for a command, the user may dis-
     able the env_reset option from the command line via the -E option.	 Addi-
     tionally, environment variables set on the command line are not subject
     to the restrictions imposed by env_check, env_delete, or env_keep.	 As
     such, only trusted users should be allowed to set variables in this man-
     ner.  If the command matched is ALL, the SETENV tag is implied for that
     command; this default may be overridden by use of the NOSETENV tag.

     LOG_INPUT and NOLOG_INPUT

     These tags override the value of the log_input option on a per-command
     basis.  For more information, see the description of log_input in the
     SUDOERS OPTIONS section below.

     LOG_OUTPUT and NOLOG_OUTPUT

     These tags override the value of the log_output option on a per-command
     basis.  For more information, see the description of log_output in the
     SUDOERS OPTIONS section below.

   Wildcards
     sudo allows shell-style wildcards (aka meta or glob characters) to be
     used in host names, path names and command line arguments in the sudoers
     file.  Wildcard matching is done via the POSIX glob(3) and fnmatch(3)
     routines.	Note that these are not regular expressions.

     *	       Matches any set of zero or more characters.

     ?	       Matches any single character.

     [...]     Matches any character in the specified range.

     [!...]    Matches any character not in the specified range.

     \x	       For any character `x', evaluates to `x'.	 This is used to
	       escape special characters such as: `*', `?', `[', and `]'.

     POSIX character classes may also be used if your system's glob(3) and
     fnmatch(3) functions support them.	 However, because the `:' character
     has special meaning in sudoers, it must be escaped.  For example:

	 /bin/ls [[alpha]]*

     Would match any file name beginning with a letter.

     Note that a forward slash (`/') will not be matched by wildcards used in
     the path name.  This is to make a path like:

	 /usr/bin/*

     match /usr/bin/who but not /usr/bin/X11/xterm.

     When matching the command line arguments, however, a slash does get
     matched by wildcards since command line arguments may contain arbitrary
     strings and not just path names.

     Wildcards in command line arguments should be used with care.  Because
     command line arguments are matched as a single, concatenated string, a
     wildcard such as `?' or `*' can match multiple words.  For example, while
     a sudoers entry like:

	 %operator ALL = /bin/cat /var/log/messages*

     will allow command like:

	 $ sudo cat /var/log/messages.1

     It will also allow:

	 $ sudo cat /var/log/messages /etc/shadow

     which is probably not what was intended.

   Exceptions to wildcard rules
     The following exceptions apply to the above rules:

     ""	       If the empty string "" is the only command line argument in the
	       sudoers entry it means that command is not allowed to be run
	       with any arguments.

     sudoedit  Command line arguments to the sudoedit built-in command should
	       always be path names, so a forward slash (`/') will not be
	       matched by a wildcard.

   Including other files from within sudoers
     It is possible to include other sudoers files from within the sudoers
     file currently being parsed using the #include and #includedir direc-
     tives.

     This can be used, for example, to keep a site-wide sudoers file in addi-
     tion to a local, per-machine file.	 For the sake of this example the
     site-wide sudoers will be /etc/sudoers and the per-machine one will be
     /etc/sudoers.local.  To include /etc/sudoers.local from within
     /etc/sudoers we would use the following line in /etc/sudoers:

	 #include /etc/sudoers.local

     When sudo reaches this line it will suspend processing of the current
     file (/etc/sudoers) and switch to /etc/sudoers.local.  Upon reaching the
     end of /etc/sudoers.local, the rest of /etc/sudoers will be processed.
     Files that are included may themselves include other files.  A hard limit
     of 128 nested include files is enforced to prevent include file loops.

     If the path to the include file is not fully-qualified (does not begin
     with a `/', it must be located in the same directory as the sudoers file
     it was included from.  For example, if /etc/sudoers contains the line:

	 #include sudoers.local

     the file that will be included is /etc/sudoers.local.

     The file name may also include the %h escape, signifying the short form
     of the host name.	In other words, if the machine's host name is
     ``xerxes'', then

	 #include /etc/sudoers.%h

     will cause sudo to include the file /etc/sudoers.xerxes.

     The #includedir directive can be used to create a sudo.d directory that
     the system package manager can drop sudoers rules into as part of package
     installation.  For example, given:

	 #includedir /etc/sudoers.d

     sudo will read each file in /etc/sudoers.d, skipping file names that end
     in `~' or contain a `.' character to avoid causing problems with package
     manager or editor temporary/backup files.	Files are parsed in sorted
     lexical order.  That is, /etc/sudoers.d/01_first will be parsed before
     /etc/sudoers.d/10_second.	Be aware that because the sorting is lexical,
     not numeric, /etc/sudoers.d/1_whoops would be loaded after
     /etc/sudoers.d/10_second.	Using a consistent number of leading zeroes in
     the file names can be used to avoid such problems.

     Note that unlike files included via #include, visudo will not edit the
     files in a #includedir directory unless one of them contains a syntax
     error.  It is still possible to run visudo with the -f flag to edit the
     files directly.

   Other special characters and reserved words
     The pound sign (`#') is used to indicate a comment (unless it is part of
     a #include directive or unless it occurs in the context of a user name
     and is followed by one or more digits, in which case it is treated as a
     uid).  Both the comment character and any text after it, up to the end of
     the line, are ignored.

     The reserved word ALL is a built-in alias that always causes a match to
     succeed.  It can be used wherever one might otherwise use a Cmnd_Alias,
     User_Alias, Runas_Alias, or Host_Alias.  You should not try to define
     your own alias called ALL as the built-in alias will be used in prefer-
     ence to your own.	Please note that using ALL can be dangerous since in a
     command context, it allows the user to run any command on the system.

     An exclamation point (`!') can be used as a logical not operator in a
     list or alias as well as in front of a Cmnd.  This allows one to exclude
     certain values.  For the `!' operator to be effective, there must be
     something for it to exclude.  For example, to match all users except for
     root one would use:

	 ALL,!root

     If the ALL, is omitted, as in:

	 !root

     it would explicitly deny root but not match any other users.  This is
     different from a true ``negation'' operator.

     Note, however, that using a `!' in conjunction with the built-in ALL
     alias to allow a user to run ``all but a few'' commands rarely works as
     intended (see SECURITY NOTES below).

     Long lines can be continued with a backslash (`\') as the last character
     on the line.

     White space between elements in a list as well as special syntactic char-
     acters in a User Specification (`=', `:', `(', `)') is optional.

     The following characters must be escaped with a backslash (`\') when used
     as part of a word (e.g. a user name or host name): `!', `=', `:', `,',
     `(', `)', `\'.

SUDOERS OPTIONS
     sudo's behavior can be modified by Default_Entry lines, as explained ear-
     lier.  A list of all supported Defaults parameters, grouped by type, are
     listed below.

     Boolean Flags:

     always_set_home   If enabled, sudo will set the HOME environment variable
		       to the home directory of the target user (which is root
		       unless the -u option is used).  This effectively means
		       that the -H option is always implied.  Note that HOME
		       is already set when the the env_reset option is
		       enabled, so always_set_home is only effective for con-
		       figurations where either env_reset is disabled or HOME
		       is present in the env_keep list.	 This flag is off by
		       default.

     authenticate      If set, users must authenticate themselves via a pass-
		       word (or other means of authentication) before they may
		       run commands.  This default may be overridden via the
		       PASSWD and NOPASSWD tags.  This flag is on by default.

     closefrom_override
		       If set, the user may use sudo's -C option which over-
		       rides the default starting point at which sudo begins
		       closing open file descriptors.  This flag is off by
		       default.

     compress_io       If set, and sudo is configured to log a command's input
		       or output, the I/O logs will be compressed using zlib.
		       This flag is on by default when sudo is compiled with
		       zlib support.

     env_editor	       If set, visudo will use the value of the EDITOR or
		       VISUAL environment variables before falling back on the
		       default editor list.  Note that this may create a secu-
		       rity hole as it allows the user to run any arbitrary
		       command as root without logging.	 A safer alternative
		       is to place a colon-separated list of editors in the
		       editor variable.	 visudo will then only use the EDITOR
		       or VISUAL if they match a value specified in editor.
		       This flag is on by default.

     env_reset	       If set, sudo will run the command in a minimal environ-
		       ment containing the TERM, PATH, HOME, MAIL, SHELL,
		       LOGNAME, USER, USERNAME and SUDO_* variables.  Any
		       variables in the caller's environment that match the
		       env_keep and env_check lists are then added, followed
		       by any variables present in the file specified by the
		       env_file option (if any).  The default contents of the
		       env_keep and env_check lists are displayed when sudo is
		       run by root with the -V option.	If the secure_path
		       option is set, its value will be used for the PATH
		       environment variable.  This flag is on by default.

     fast_glob	       Normally, sudo uses the glob(3) function to do shell-
		       style globbing when matching path names.	 However,
		       since it accesses the file system, glob(3) can take a
		       long time to complete for some patterns, especially
		       when the pattern references a network file system that
		       is mounted on demand (auto mounted).  The fast_glob
		       option causes sudo to use the fnmatch(3) function,
		       which does not access the file system to do its match-
		       ing.  The disadvantage of fast_glob is that it is
		       unable to match relative path names such as ./ls or
		       ../bin/ls.  This has security implications when path
		       names that include globbing characters are used with
		       the negation operator, `!', as such rules can be triv-
		       ially bypassed.	As such, this option should not be
		       used when sudoers contains rules that contain negated
		       path names which include globbing characters.  This
		       flag is off by default.

     fqdn	       Set this flag if you want to put fully qualified host
		       names in the sudoers file when the local host name (as
		       returned by the hostname command) does not contain the
		       domain name.  In other words, instead of myhost you
		       would use myhost.mydomain.edu.  You may still use the
		       short form if you wish (and even mix the two).  This
		       option is only effective when the ``canonical'' host
		       name, as returned by the getaddrinfo() or
		       gethostbyname() function, is a fully-qualified domain
		       name.  This is usually the case when the system is con-
		       figured to use DNS for host name resolution.

		       If the system is configured to use the /etc/hosts file
		       in preference to DNS, the ``canonical'' host name may
		       not be fully-qualified.	The order that sources are
		       queried for hosts name resolution is usually specified
		       in the /etc/nsswitch.conf, /etc/netsvc.conf,
		       /etc/host.conf, or, in some cases, /etc/resolv.conf
		       file.  In the /etc/hosts file, the first host name of
		       the entry is considered to be the ``canonical'' name;
		       subsequent names are aliases that are not used by
		       sudoers.	 For example, the following hosts file line
		       for the machine ``xyzzy'' has the fully-qualified
		       domain name as the ``canonical'' host name, and the
		       short version as an alias.

			     192.168.1.1    xyzzy.sudo.ws xyzzy

		       If the machine's hosts file entry is not formatted
		       properly, the fqdn option will not be effective if it
		       is queried before DNS.

		       Beware that when using DNS for host name resolution,
		       turning on fqdn requires sudoers to make DNS lookups
		       which renders sudo unusable if DNS stops working (for
		       example if the machine is disconnected from the net-
		       work).  Also note that just like with the hosts file,
		       you must use the ``canonical'' name as DNS knows it.
		       That is, you may not use a host alias (CNAME entry) due
		       to performance issues and the fact that there is no way
		       to get all aliases from DNS.

		       This flag is off by default.

     ignore_dot	       If set, sudo will ignore "." or "" (both denoting cur-
		       rent directory) in the PATH environment variable; the
		       PATH itself is not modified.  This flag is on by
		       default.

     ignore_local_sudoers
		       If set via LDAP, parsing of /etc/sudoers will be
		       skipped.	 This is intended for Enterprises that wish to
		       prevent the usage of local sudoers files so that only
		       LDAP is used.  This thwarts the efforts of rogue opera-
		       tors who would attempt to add roles to /etc/sudoers.
		       When this option is present, /etc/sudoers does not even
		       need to exist.  Since this option tells sudo how to
		       behave when no specific LDAP entries have been matched,
		       this sudoOption is only meaningful for the cn=defaults
		       section.	 This flag is off by default.

     insults	       If set, sudo will insult users when they enter an
		       incorrect password.  This flag is off by default.

     log_host	       If set, the host name will be logged in the (non-sys-
		       log) sudo log file.  This flag is off by default.

     log_input	       If set, sudo will run the command in a pseudo tty and
		       log all user input.  If the standard input is not con-
		       nected to the user's tty, due to I/O redirection or
		       because the command is part of a pipeline, that input
		       is also captured and stored in a separate log file.

		       Input is logged to the directory specified by the
		       iolog_dir option (/var/log/sudo-io by default) using a
		       unique session ID that is included in the normal sudo
		       log line, prefixed with ``TSID=''.  The iolog_file
		       option may be used to control the format of the session
		       ID.

		       Note that user input may contain sensitive information
		       such as passwords (even if they are not echoed to the
		       screen), which will be stored in the log file unen-
		       crypted.	 In most cases, logging the command output via
		       log_output is all that is required.

     log_output	       If set, sudo will run the command in a pseudo tty and
		       log all output that is sent to the screen, similar to
		       the script(1) command.  If the standard output or stan-
		       dard error is not connected to the user's tty, due to
		       I/O redirection or because the command is part of a
		       pipeline, that output is also captured and stored in
		       separate log files.

		       Output is logged to the directory specified by the
		       iolog_dir option (/var/log/sudo-io by default) using a
		       unique session ID that is included in the normal sudo
		       log line, prefixed with ``TSID=''.  The iolog_file
		       option may be used to control the format of the session
		       ID.

		       Output logs may be viewed with the sudoreplay(8) util-
		       ity, which can also be used to list or search the
		       available logs.

     log_year	       If set, the four-digit year will be logged in the (non-
		       syslog) sudo log file.  This flag is off by default.

     long_otp_prompt   When validating with a One Time Password (OTP) scheme
		       such as S/Key or OPIE, a two-line prompt is used to
		       make it easier to cut and paste the challenge to a
		       local window.  It's not as pretty as the default but
		       some people find it more convenient.  This flag is off
		       by default.

     mail_always       Send mail to the mailto user every time a users runs
		       sudo.  This flag is off by default.

     mail_badpass      Send mail to the mailto user if the user running sudo
		       does not enter the correct password.  If the command
		       the user is attempting to run is not permitted by
		       sudoers and one of the mail_always, mail_no_host,
		       mail_no_perms or mail_no_user flags are set, this flag
		       will have no effect.  This flag is off by default.

     mail_no_host      If set, mail will be sent to the mailto user if the
		       invoking user exists in the sudoers file, but is not
		       allowed to run commands on the current host.  This flag
		       is off by default.

     mail_no_perms     If set, mail will be sent to the mailto user if the
		       invoking user is allowed to use sudo but the command
		       they are trying is not listed in their sudoers file
		       entry or is explicitly denied.  This flag is off by
		       default.

     mail_no_user      If set, mail will be sent to the mailto user if the
		       invoking user is not in the sudoers file.  This flag is
		       on by default.

     noexec	       If set, all commands run via sudo will behave as if the
		       NOEXEC tag has been set, unless overridden by a EXEC
		       tag.  See the description of NOEXEC and EXEC below as
		       well as the Preventing shell escapes section at the end
		       of this manual.	This flag is off by default.

     path_info	       Normally, sudo will tell the user when a command could
		       not be found in their PATH environment variable.	 Some
		       sites may wish to disable this as it could be used to
		       gather information on the location of executables that
		       the normal user does not have access to.	 The disadvan-
		       tage is that if the executable is simply not in the
		       user's PATH, sudo will tell the user that they are not
		       allowed to run it, which can be confusing.  This flag
		       is on by default.

     passprompt_override
		       The password prompt specified by passprompt will nor-
		       mally only be used if the password prompt provided by
		       systems such as PAM matches the string ``Password:''.
		       If passprompt_override is set, passprompt will always
		       be used.	 This flag is off by default.

     preserve_groups   By default, sudo will initialize the group vector to
		       the list of groups the target user is in.  When
		       preserve_groups is set, the user's existing group vec-
		       tor is left unaltered.  The real and effective group
		       IDs, however, are still set to match the target user.
		       This flag is off by default.

     pwfeedback	       By default, sudo reads the password like most other
		       Unix programs, by turning off echo until the user hits
		       the return (or enter) key.  Some users become confused
		       by this as it appears to them that sudo has hung at
		       this point.  When pwfeedback is set, sudo will provide
		       visual feedback when the user presses a key.  Note that
		       this does have a security impact as an onlooker may be
		       able to determine the length of the password being
		       entered.	 This flag is off by default.

     requiretty	       If set, sudo will only run when the user is logged in
		       to a real tty.  When this flag is set, sudo can only be
		       run from a login session and not via other means such
		       as cron(8) or cgi-bin scripts.  This flag is off by
		       default.

     root_sudo	       If set, root is allowed to run sudo too.	 Disabling
		       this prevents users from ``chaining'' sudo commands to
		       get a root shell by doing something like ``sudo sudo
		       /bin/sh''.  Note, however, that turning off root_sudo
		       will also prevent root from running sudoedit.  Dis-
		       abling root_sudo provides no real additional security;
		       it exists purely for historical reasons.	 This flag is
		       on by default.

     rootpw	       If set, sudo will prompt for the root password instead
		       of the password of the invoking user.  This flag is off
		       by default.

     runaspw	       If set, sudo will prompt for the password of the user
		       defined by the runas_default option (defaults to root)
		       instead of the password of the invoking user.  This
		       flag is off by default.

     set_home	       If enabled and sudo is invoked with the -s option the
		       HOME environment variable will be set to the home
		       directory of the target user (which is root unless the
		       -u option is used).  This effectively makes the -s
		       option imply -H.	 Note that HOME is already set when
		       the the env_reset option is enabled, so set_home is
		       only effective for configurations where either
		       env_reset is disabled or HOME is present in the
		       env_keep list.  This flag is off by default.

     set_logname       Normally, sudo will set the LOGNAME, USER and USERNAME
		       environment variables to the name of the target user
		       (usually root unless the -u option is given).  However,
		       since some programs (including the RCS revision control
		       system) use LOGNAME to determine the real identity of
		       the user, it may be desirable to change this behavior.
		       This can be done by negating the set_logname option.
		       Note that if the env_reset option has not been dis-
		       abled, entries in the env_keep list will override the
		       value of set_logname.  This flag is on by default.

     set_utmp	       When enabled, sudo will create an entry in the utmp (or
		       utmpx) file when a pseudo-tty is allocated.  A pseudo-
		       tty is allocated by sudo when the log_input, log_output
		       or use_pty flags are enabled.  By default, the new
		       entry will be a copy of the user's existing utmp entry
		       (if any), with the tty, time, type and pid fields
		       updated.	 This flag is on by default.

     setenv	       Allow the user to disable the env_reset option from the
		       command line via the -E option.	Additionally, environ-
		       ment variables set via the command line are not subject
		       to the restrictions imposed by env_check, env_delete,
		       or env_keep.  As such, only trusted users should be
		       allowed to set variables in this manner.	 This flag is
		       off by default.

     shell_noargs      If set and sudo is invoked with no arguments it acts as
		       if the -s option had been given.	 That is, it runs a
		       shell as root (the shell is determined by the SHELL
		       environment variable if it is set, falling back on the
		       shell listed in the invoking user's /etc/passwd entry
		       if not).	 This flag is off by default.

     stay_setuid       Normally, when sudo executes a command the real and
		       effective UIDs are set to the target user (root by
		       default).  This option changes that behavior such that
		       the real UID is left as the invoking user's UID.	 In
		       other words, this makes sudo act as a setuid wrapper.
		       This can be useful on systems that disable some poten-
		       tially dangerous functionality when a program is run
		       setuid.	This option is only effective on systems that
		       support either the setreuid(2) or setresuid(2) system
		       call.  This flag is off by default.

     targetpw	       If set, sudo will prompt for the password of the user
		       specified by the -u option (defaults to root) instead
		       of the password of the invoking user.  In addition, the
		       time stamp file name will include the target user's
		       name.  Note that this flag precludes the use of a uid
		       not listed in the passwd database as an argument to the
		       -u option.  This flag is off by default.

     tty_tickets       If set, users must authenticate on a per-tty basis.
		       With this flag enabled, sudo will use a file named for
		       the tty the user is logged in on in the user's time
		       stamp directory.	 If disabled, the time stamp of the
		       directory is used instead.  This flag is on by default.

     umask_override    If set, sudo will set the umask as specified by sudoers
		       without modification.  This makes it possible to spec-
		       ify a more permissive umask in sudoers than the user's
		       own umask and matches historical behavior.  If
		       umask_override is not set, sudo will set the umask to
		       be the union of the user's umask and what is specified
		       in sudoers.  This flag is off by default.  If set, sudo
		       will run the command in a pseudo-pty even if no I/O
		       logging is being gone.  A malicious program run under
		       sudo could conceivably fork a background process that
		       retains to the user's terminal device after the main
		       program has finished executing.	Use of this option
		       will make that impossible.  This flag is off by
		       default.

     utmp_runas	       If set, sudo will store the name of the runas user when
		       updating the utmp (or utmpx) file.  By default, sudo
		       stores the name of the invoking user.  This flag is off
		       by default.

     visiblepw	       By default, sudo will refuse to run if the user must
		       enter a password but it is not possible to disable echo
		       on the terminal.	 If the visiblepw flag is set, sudo
		       will prompt for a password even when it would be visi-
		       ble on the screen.  This makes it possible to run
		       things like ``ssh somehost sudo ls'' since by default,
		       ssh(1) does not allocate a tty when running a command.
		       This flag is off by default.

     Integers:

     closefrom	       Before it executes a command, sudo will close all open
		       file descriptors other than standard input, standard
		       output and standard error (ie: file descriptors 0-2).
		       The closefrom option can be used to specify a different
		       file descriptor at which to start closing.  The default
		       is 3.

     passwd_tries      The number of tries a user gets to enter his/her pass-
		       word before sudo logs the failure and exits.  The
		       default is 3.

     Integers that can be used in a boolean context:

     loglinelen	       Number of characters per line for the file log.	This
		       value is used to decide when to wrap lines for nicer
		       log files.  This has no effect on the syslog log file,
		       only the file log.  The default is 80 (use 0 or negate
		       the option to disable word wrap).

     passwd_timeout    Number of minutes before the sudo password prompt times
		       out, or 0 for no timeout.  The timeout may include a
		       fractional component if minute granularity is insuffi-
		       cient, for example 2.5.	The default is 5.

     timestamp_timeout
		       Number of minutes that can elapse before sudo will ask
		       for a passwd again.  The timeout may include a frac-
		       tional component if minute granularity is insufficient,
		       for example 2.5.	 The default is 5.  Set this to 0 to
		       always prompt for a password.  If set to a value less
		       than 0 the user's time stamp will never expire.	This
		       can be used to allow users to create or delete their
		       own time stamps via ``sudo -v'' and ``sudo -k'' respec-
		       tively.

     umask	       Umask to use when running the command.  Negate this
		       option or set it to 0777 to preserve the user's umask.
		       The actual umask that is used will be the union of the
		       user's umask and the value of the umask option, which
		       defaults to 0022.  This guarantees that sudo never low-
		       ers the umask when running a command.  Note: on systems
		       that use PAM, the default PAM configuration may specify
		       its own umask which will override the value set in
		       sudoers.

     Strings:

     badpass_message   Message that is displayed if a user enters an incorrect
		       password.  The default is Sorry, try again. unless
		       insults are enabled.

     editor	       A colon (`:') separated list of editors allowed to be
		       used with visudo.  visudo will choose the editor that
		       matches the user's EDITOR environment variable if pos-
		       sible, or the first editor in the list that exists and
		       is executable.  The default is /usr/local/bin/vi.

     iolog_dir	       The top-level directory to use when constructing the
		       path name for the input/output log directory.  Only
		       used if the log_input or log_output options are enabled
		       or when the LOG_INPUT or LOG_OUTPUT tags are present
		       for a command.  The session sequence number, if any, is
		       stored in the directory.	 The default is
		       /var/log/sudo-io.

		       The following percent (`%') escape sequences are sup-
		       ported:

		       %{seq}
			     expanded to a monotonically increasing base-36
			     sequence number, such as 0100A5, where every two
			     digits are used to form a new directory, e.g.
			     01/00/A5

		       %{user}
			     expanded to the invoking user's login name

		       %{group}
			     expanded to the name of the invoking user's real
			     group ID

		       %{runas_user}
			     expanded to the login name of the user the com-
			     mand will be run as (e.g. root)

		       %{runas_group}
			     expanded to the group name of the user the com-
			     mand will be run as (e.g. wheel)

		       %{hostname}
			     expanded to the local host name without the
			     domain name

		       %{command}
			     expanded to the base name of the command being
			     run

		       In addition, any escape sequences supported by the sys-
		       tem's strftime(3) function will be expanded.

		       To include a literal `%' character, the string `%%'
		       should be used.

     iolog_file	       The path name, relative to iolog_dir, in which to store
		       input/output logs when the log_input or log_output
		       options are enabled or when the LOG_INPUT or LOG_OUTPUT
		       tags are present for a command.	Note that iolog_file
		       may contain directory components.  The default is
		       ``%{seq}''.

		       See the iolog_dir option above for a list of supported
		       percent (`%') escape sequences.

		       In addition to the escape sequences, path names that
		       end in six or more Xs will have the Xs replaced with a
		       unique combination of digits and letters, similar to
		       the mktemp(3) function.

     mailsub	       Subject of the mail sent to the mailto user.  The
		       escape %h will expand to the host name of the machine.
		       Default is ``*** SECURITY information for %h ***''.

     noexec_file       This option is no longer supported.  The path to the
		       noexec file should now be set in the /etc/sudo.conf
		       file.

     pam_login_service
		       On systems that use PAM for authentication, this is the
		       service name used when the -i option is specified.  The
		       default value is ``sudo-i''.  See the description of
		       pam_service for more information.

     pam_service       On systems that use PAM for authentication, the service
		       name specifies the PAM policy to apply.	This usually
		       corresponds to an entry in the pam.conf file or a file
		       in the /etc/pam.d directory.  The default value is
		       ``sudo''.

     passprompt	       The default prompt to use when asking for a password;
		       can be overridden via the -p option or the SUDO_PROMPT
		       environment variable.  The following percent (`%')
		       escape sequences are supported:

		       %H    expanded to the local host name including the
			     domain name (only if the machine's host name is
			     fully qualified or the fqdn option is set)

		       %h    expanded to the local host name without the
			     domain name

		       %p    expanded to the user whose password is being
			     asked for (respects the rootpw, targetpw and
			     runaspw flags in sudoers)

		       %U    expanded to the login name of the user the com-
			     mand will be run as (defaults to root)

		       %u    expanded to the invoking user's login name

		       %%    two consecutive % characters are collapsed into a
			     single % character

		       The default value is ``[sudo] password for %p:''.  The
		       default SELinux role to use when constructing a new
		       security context to run the command.  The default role
		       may be overridden on a per-command basis in sudoers or
		       via command line options.  This option is only avail-
		       able when sudo is built with SELinux support.

     runas_default     The default user to run commands as if the -u option is
		       not specified on the command line.  This defaults to
		       root.

     syslog_badpri     Syslog priority to use when user authenticates unsuc-
		       cessfully.  Defaults to alert.

		       The following syslog priorities are supported: alert,
		       crit, debug, emerg, err, info, notice, and warning.

     syslog_goodpri    Syslog priority to use when user authenticates success-
		       fully.  Defaults to notice.

		       See syslog_badpri for the list of supported syslog pri-
		       orities.

     sudoers_locale    Locale to use when parsing the sudoers file, logging
		       commands, and sending email.  Note that changing the
		       locale may affect how sudoers is interpreted.  Defaults
		       to ``C''.

     timestampdir      The directory in which sudo stores its time stamp
		       files.  The default is /var/db/sudo.

     timestampowner    The owner of the time stamp directory and the time
		       stamps stored therein.  The default is root.

     type	       The default SELinux type to use when constructing a new
		       security context to run the command.  The default type
		       may be overridden on a per-command basis in sudoers or
		       via command line options.  This option is only avail-
		       able when sudo is built with SELinux support.

     Strings that can be used in a boolean context:

     env_file	   The env_file option specifies the fully qualified path to a
		   file containing variables to be set in the environment of
		   the program being run.  Entries in this file should either
		   be of the form ``VARIABLE=value'' or ``export
		   VARIABLE=value''.  The value may optionally be surrounded
		   by single or double quotes.	Variables in this file are
		   subject to other sudo environment settings such as env_keep
		   and env_check.

     exempt_group  Users in this group are exempt from password and PATH
		   requirements.  The group name specified should not include
		   a % prefix.	This is not set by default.

     group_plugin  A string containing a sudoers group plugin with optional
		   arguments.  This can be used to implement support for the
		   nonunix_group syntax described earlier.  The string should
		   consist of the plugin path, either fully-qualified or rela-
		   tive to the /usr/libexec directory, followed by any config-
		   uration arguments the plugin requires.  These arguments (if
		   any) will be passed to the plugin's initialization func-
		   tion.  If arguments are present, the string must be
		   enclosed in double quotes ("").

		   For example, given /etc/sudo-group, a group file in Unix
		   group format, the sample group plugin can be used:

		   Defaults group_plugin="sample_group.so /etc/sudo-group"

		   For more information see sudo_plugin(5).

     lecture	   This option controls when a short lecture will be printed
		   along with the password prompt.  It has the following pos-
		   sible values:

		   always  Always lecture the user.

		   never   Never lecture the user.

		   once	   Only lecture the user the first time they run sudo.

		   If no value is specified, a value of once is implied.
		   Negating the option results in a value of never being used.
		   The default value is once.

     lecture_file  Path to a file containing an alternate sudo lecture that
		   will be used in place of the standard lecture if the named
		   file exists.	 By default, sudo uses a built-in lecture.

     listpw	   This option controls when a password will be required when
		   a user runs sudo with the -l option.	 It has the following
		   possible values:

		   all	     All the user's sudoers entries for the current
			     host must have the NOPASSWD flag set to avoid
			     entering a password.

		   always    The user must always enter a password to use the
			     -l option.

		   any	     At least one of the user's sudoers entries for
			     the current host must have the NOPASSWD flag set
			     to avoid entering a password.

		   never     The user need never enter a password to use the
			     -l option.

		   If no value is specified, a value of any is implied.
		   Negating the option results in a value of never being used.
		   The default value is any.

     logfile	   Path to the sudo log file (not the syslog log file).	 Set-
		   ting a path turns on logging to a file; negating this
		   option turns it off.	 By default, sudo logs via syslog.

     mailerflags   Flags to use when invoking mailer. Defaults to -t.

     mailerpath	   Path to mail program used to send warning mail.  Defaults
		   to the path to sendmail found at configure time.

     mailfrom	   Address to use for the ``from'' address when sending warn-
		   ing and error mail.	The address should be enclosed in dou-
		   ble quotes ("") to protect against sudo interpreting the @
		   sign.  Defaults to the name of the user running sudo.

     mailto	   Address to send warning and error mail to.  The address
		   should be enclosed in double quotes ("") to protect against
		   sudo interpreting the @ sign.  Defaults to root.

     secure_path   Path used for every command run from sudo.  If you don't
		   trust the people running sudo to have a sane PATH environ-
		   ment variable you may want to use this.  Another use is if
		   you want to have the ``root path'' be separate from the
		   ``user path''.  Users in the group specified by the
		   exempt_group option are not affected by secure_path.	 This
		   option is not set by default.

     syslog	   Syslog facility if syslog is being used for logging (negate
		   to disable syslog logging).	Defaults to authpriv.

		   The following syslog facilities are supported: authpriv (if
		   your OS supports it), auth, daemon, user, local0, local1,
		   local2, local3, local4, local5, local6, and local7.

     verifypw	   This option controls when a password will be required when
		   a user runs sudo with the -v option.	 It has the following
		   possible values:

		   all	   All the user's sudoers entries for the current host
			   must have the NOPASSWD flag set to avoid entering a
			   password.

		   always  The user must always enter a password to use the -v
			   option.

		   any	   At least one of the user's sudoers entries for the
			   current host must have the NOPASSWD flag set to
			   avoid entering a password.

		   never   The user need never enter a password to use the -v
			   option.

		   If no value is specified, a value of all is implied.
		   Negating the option results in a value of never being used.
		   The default value is all.

     Lists that can be used in a boolean context:

     env_check	       Environment variables to be removed from the user's
		       environment if unless they are considered ``safe''.
		       For all variables except TZ, ``safe'' means that the
		       variable's value does not contain any `%' or `/' char-
		       acters.	This can be used to guard against printf-style
		       format vulnerabilities in poorly-written programs.  The
		       TZ variable is considerd unsafe if any of the following
		       are true:

		       o   It consists of a fully-qualified path name, option-
			   ally prefixed with a colon (`:'), that does not
			   match the location of the zoneinfo directory.

		       o   It contains a .. path element.

		       o   It contains white space or non-printable charac-
			   ters.

		       o   It is longer than the value of PATH_MAX.

		       The argument may be a double-quoted, space-separated
		       list or a single value without double-quotes.  The list
		       can be replaced, added to, deleted from, or disabled by
		       using the =, +=, -=, and ! operators respectively.
		       Regardless of whether the env_reset option is enabled
		       or disabled, variables specified by env_check will be
		       preserved in the environment if they pass the aforemen-
		       tioned check.  The default list of environment vari-
		       ables to check is displayed when sudo is run by root
		       with the -V option.

     env_delete	       Environment variables to be removed from the user's
		       environment when the env_reset option is not in effect.
		       The argument may be a double-quoted, space-separated
		       list or a single value without double-quotes.  The list
		       can be replaced, added to, deleted from, or disabled by
		       using the =, +=, -=, and ! operators respectively.  The
		       default list of environment variables to remove is dis-
		       played when sudo is run by root with the -V option.
		       Note that many operating systems will remove poten-
		       tially dangerous variables from the environment of any
		       setuid process (such as sudo).

     env_keep	       Environment variables to be preserved in the user's
		       environment when the env_reset option is in effect.
		       This allows fine-grained control over the environment
		       sudo-spawned processes will receive.  The argument may
		       be a double-quoted, space-separated list or a single
		       value without double-quotes.  The list can be replaced,
		       added to, deleted from, or disabled by using the =, +=,
		       -=, and ! operators respectively.  The default list of
		       variables to keep is displayed when sudo is run by root
		       with the -V option.

LOG FORMAT
     sudoers can log events using either syslog(3) or a simple log file.  In
     each case the log format is almost identical.

   Accepted command log entries
     Commands that sudo runs are logged using the following format (split into
     multiple lines for readability):

	 date hostname progname: username : TTY=ttyname ; PWD=cwd ; \
	     USER=runasuser ; GROUP=runasgroup ; TSID=logid ; \
	     ENV=env_vars COMMAND=command

     Where the fields are as follows:

     date	   The date the command was run.  Typically, this is in the
		   format ``MMM, DD, HH:MM:SS''.  If logging via syslog(3),
		   the actual date format is controlled by the syslog daemon.
		   If logging to a file and the log_year option is enabled,
		   the date will also include the year.

     hostname	   The name of the host sudo was run on.  This field is only
		   present when logging via syslog(3).

     progname	   The name of the program, usually sudo or sudoedit.  This
		   field is only present when logging via syslog(3).

     username	   The login name of the user who ran sudo.

     ttyname	   The short name of the terminal (e.g. ``console'',
		   ``tty01'', or ``pts/0'') sudo was run on, or ``unknown'' if
		   there was no terminal present.

     cwd	   The current working directory that sudo was run in.

     runasuser	   The user the command was run as.

     runasgroup	   The group the command was run as if one was specified on
		   the command line.

     logid	   An I/O log identifier that can be used to replay the com-
		   mand's output.  This is only present when the log_input or
		   log_output option is enabled.

     env_vars	   A list of environment variables specified on the command
		   line, if specified.

     command	   The actual command that was executed.

     Messages are logged using the locale specified by sudoers_locale, which
     defaults to the ``C'' locale.

   Denied command log entries
     If the user is not allowed to run the command, the reason for the denial
     will follow the user name.	 Possible reasons include:

     user NOT in sudoers
       The user is not listed in the sudoers file.

     user NOT authorized on host
       The user is listed in the sudoers file but is not allowed to run com-
       mands on the host.

     command not allowed
       The user is listed in the sudoers file for the host but they are not
       allowed to run the specified command.

     3 incorrect password attempts
       The user failed to enter their password after 3 tries.  The actual num-
       ber of tries will vary based on the number of failed attempts and the
       value of the passwd_tries option.

     a password is required
       sudo's -n option was specified but a password was required.

     sorry, you are not allowed to set the following environment variables
       The user specified environment variables on the command line that were
       not allowed by sudoers.

   Error log entries
     If an error occurs, sudoers will log a message and, in most cases, send a
     message to the administrator via email.  Possible errors include:

     parse error in /etc/sudoers near line N
       sudoers encountered an error when parsing the specified file.  In some
       cases, the actual error may be one line above or below the line number
       listed, depending on the type of error.

     problem with defaults entries
       The sudoers file contains one or more unknown Defaults settings.	 This
       does not prevent sudo from running, but the sudoers file should be
       checked using visudo.

     timestamp owner (username): No such user
       The time stamp directory owner, as specified by the timestampowner set-
       ting, could not be found in the password database.

     unable to open/read /etc/sudoers
       The sudoers file could not be opened for reading.  This can happen when
       the sudoers file is located on a remote file system that maps user ID 0
       to a different value.  Normally, sudoers tries to open sudoers using
       group permissions to avoid this problem.	 Consider changing the owner-
       ship of /etc/sudoers by adding an option like ``sudoers_uid=N'' (where
       `N' is the user ID that owns the sudoers file) to the sudoers plugin
       line in the /etc/sudo.conf file.

     unable to stat /etc/sudoers
       The /etc/sudoers file is missing.

     /etc/sudoers is not a regular file
       The /etc/sudoers file exists but is not a regular file or symbolic
       link.

     /etc/sudoers is owned by uid N, should be 0
       The sudoers file has the wrong owner.  If you wish to change the
       sudoers file owner, please add ``sudoers_uid=N'' (where `N' is the user
       ID that owns the sudoers file) to the sudoers plugin line in the
       /etc/sudo.conf file.

     /etc/sudoers is world writable
       The permissions on the sudoers file allow all users to write to it.
       The sudoers file must not be world-writable, the default file mode is
       0440 (readable by owner and group, writable by none).  The default mode
       may be changed via the ``sudoers_mode'' option to the sudoers plugin
       line in the /etc/sudo.conf file.

     /etc/sudoers is owned by gid N, should be 1
       The sudoers file has the wrong group ownership.	If you wish to change
       the sudoers file group ownership, please add ``sudoers_gid=N'' (where
       `N' is the group ID that owns the sudoers file) to the sudoers plugin
       line in the /etc/sudo.conf file.

     unable to open /var/db/sudo/username/ttyname
       sudoers was unable to read or create the user's time stamp file.

     unable to write to /var/db/sudo/username/ttyname
       sudoers was unable to write to the user's time stamp file.

     unable to mkdir to /var/db/sudo/username
       sudoers was unable to create the user's time stamp directory.

   Notes on logging via syslog
     By default, sudoers logs messages via syslog(3).  The date, hostname, and
     progname fields are added by the syslog daemon, not sudoers itself.  As
     such, they may vary in format on different systems.

     On most systems, syslog(3) has a relatively small log buffer.  To prevent
     the command line arguments from being truncated, sudoers will split up
     log messages that are larger than 960 characters (not including the date,
     hostname, and the string ``sudo'').  When a message is split, additional
     parts will include the string ``(command continued)'' after the user name
     and before the continued command line arguments.

   Notes on logging to a file
     If the logfile option is set, sudoers will log to a local file, such as
     /var/log/sudo.  When logging to a file, sudoers uses a format similar to
     syslog(3), with a few important differences:

     1.	  The progname and hostname fields are not present.

     2.	  If the log_year option is enabled, the date will also include the
	  year.

     3.	  Lines that are longer than loglinelen characters (80 by default) are
	  word-wrapped and continued on the next line with a four character
	  indent.  This makes entries easier to read for a human being, but
	  makes it more difficult to use grep(1) on the log files.  If the
	  loglinelen option is set to 0 (or negated with a `!'), word wrap
	  will be disabled.

SUDO.CONF
     The /etc/sudo.conf file determines which plugins the sudo front end will
     load.  If no /etc/sudo.conf file is present, or it contains no Plugin
     lines, sudo will use the sudoers security policy and I/O logging, which
     corresponds to the following /etc/sudo.conf file.

     #
     # Default /etc/sudo.conf file
     #
     # Format:
     #	 Plugin plugin_name plugin_path plugin_options ...
     #	 Path askpass /path/to/askpass
     #	 Path noexec /path/to/sudo_noexec.so
     #	 Debug sudo /var/log/sudo_debug all@warn
     #	 Set disable_coredump true
     #
     # The plugin_path is relative to /usr/libexec unless
     #	 fully qualified.
     # The plugin_name corresponds to a global symbol in the plugin
     #	 that contains the plugin interface structure.
     # The plugin_options are optional.
     #
     Plugin policy_plugin sudoers.so
     Plugin io_plugin sudoers.so

   Plugin options
     Starting with sudo 1.8.5, it is possible to pass options to the sudoers
     plugin.  Options may be listed after the path to the plugin (i.e. after
     sudoers.so); multiple options should be space-separated.  For example:

     Plugin sudoers_policy sudoers.so sudoers_file=/etc/sudoers sudoers_uid=0 sudoers_gid=0 sudoers_mode=0440

     The following plugin options are supported:

     sudoers_file=pathname
	       The sudoers_file option can be used to override the default
	       path to the sudoers file.

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

     sudoers_gid=gid
	       The sudoers_gid option can be used to override the default
	       group of the sudoers file.  It should be specified as a numeric
	       group ID.

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

   Debug flags
     Versions 1.8.4 and higher of the sudoers plugin supports a debugging
     framework that can help track down what the plugin is doing internally if
     there is a problem.  This can be configured in the /etc/sudo.conf file as
     described in sudo(8).

     The sudoers plugin uses the same debug flag format as the sudo front-end:
     subsystem@priority.

     The priorities used by sudoers, in order of decreasing severity, are:
     crit, err, warn, notice, diag, info, trace and debug.  Each priority,
     when specified, also includes all priorities higher than it.  For exam-
     ple, a priority of notice would include debug messages logged at notice
     and higher.

     The following subsystems are used by sudoers:

     alias     User_Alias, Runas_Alias, Host_Alias and Cmnd_Alias processing

     all       matches every subsystem

     audit     BSM and Linux audit code

     auth      user authentication

     defaults  sudoers Defaults settings

     env       environment handling

     ldap      LDAP-based sudoers

     logging   logging support

     match     matching of users, groups, hosts and netgroups in sudoers

     netif     network interface handling

     nss       network service switch handling in sudoers

     parser    sudoers file parsing

     perms     permission setting

     plugin    The equivalent of main for the plugin.

     pty       pseudo-tty related code

     rbtree    redblack tree internals

     util      utility functions

FILES
     /etc/sudo.conf	       Sudo front end configuration

     /etc/sudoers	       List of who can run what

     /etc/group		       Local groups file

     /etc/netgroup	       List of network groups

     /var/log/sudo-io	       I/O log files

     /var/db/sudo	       Directory containing time stamps for the
			       sudoers security policy

     /etc/environment	       Initial environment for -i mode on AIX and
			       Linux systems

EXAMPLES
     Below are example sudoers entries.	 Admittedly, some of these are a bit
     contrived.	 First, we allow a few environment variables to pass and then
     define our aliases:

     # Run X applications through sudo; HOME is used to find the
     # .Xauthority file.  Note that other programs use HOME to find
     # configuration files and this may lead to privilege escalation!
     Defaults env_keep += "DISPLAY HOME"

     # User alias specification
     User_Alias	     FULLTIMERS = millert, mikef, dowdy
     User_Alias	     PARTTIMERS = bostley, jwfox, crawl
     User_Alias	     WEBMASTERS = will, wendy, wim

     # Runas alias specification
     Runas_Alias     OP = root, operator
     Runas_Alias     DB = oracle, sybase
     Runas_Alias     ADMINGRP = adm, oper

     # Host alias specification
     Host_Alias	     SPARC = bigtime, eclipse, moet, anchor :\
		     SGI = grolsch, dandelion, black :\
		     ALPHA = widget, thalamus, foobar :\
		     HPPA = boa, nag, python
     Host_Alias	     CUNETS = 128.138.0.0/255.255.0.0
     Host_Alias	     CSNETS = 128.138.243.0, 128.138.204.0/24, 128.138.242.0
     Host_Alias	     SERVERS = master, mail, www, ns
     Host_Alias	     CDROM = orion, perseus, hercules

     # Cmnd alias specification
     Cmnd_Alias	     DUMPS = /usr/bin/mt, /usr/sbin/dump, /usr/sbin/rdump,\
			     /usr/sbin/restore, /usr/sbin/rrestore
     Cmnd_Alias	     KILL = /usr/bin/kill
     Cmnd_Alias	     PRINTING = /usr/sbin/lpc, /usr/bin/lprm
     Cmnd_Alias	     SHUTDOWN = /usr/sbin/shutdown
     Cmnd_Alias	     HALT = /usr/sbin/halt
     Cmnd_Alias	     REBOOT = /usr/sbin/reboot
     Cmnd_Alias	     SHELLS = /usr/bin/sh, /usr/bin/csh, /usr/bin/ksh,\
			      /usr/local/bin/tcsh, /usr/bin/rsh,\
			      /usr/local/bin/zsh
     Cmnd_Alias	     SU = /usr/bin/su
     Cmnd_Alias	     PAGERS = /usr/bin/more, /usr/bin/pg, /usr/bin/less

     Here we override some of the compiled in default values.  We want sudo to
     log via syslog(3) using the auth facility in all cases.  We don't want to
     subject the full time staff to the sudo lecture, user millert need not
     give a password, and we don't want to reset the LOGNAME, USER or USERNAME
     environment variables when running commands as root.  Additionally, on
     the machines in the SERVERS Host_Alias, we keep an additional local log
     file and make sure we log the year in each log line since the log entries
     will be kept around for several years.  Lastly, we disable shell escapes
     for the commands in the PAGERS Cmnd_Alias (/usr/bin/more, /usr/bin/pg and
     /usr/bin/less).

     # Override built-in defaults
     Defaults		     syslog=auth
     Defaults>root	     !set_logname
     Defaults:FULLTIMERS     !lecture
     Defaults:millert	     !authenticate
     Defaults@SERVERS	     log_year, logfile=/var/log/sudo.log
     Defaults!PAGERS	     noexec

     The User specification is the part that actually determines who may run
     what.

     root	     ALL = (ALL) ALL
     %wheel	     ALL = (ALL) ALL

     We let root and any user in group wheel run any command on any host as
     any user.

     FULLTIMERS	     ALL = NOPASSWD: ALL

     Full time sysadmins (millert, mikef, and dowdy) may run any command on
     any host without authenticating themselves.

     PARTTIMERS	     ALL = ALL

     Part time sysadmins bostley, jwfox, and crawl) may run any command on any
     host but they must authenticate themselves first (since the entry lacks
     the NOPASSWD tag).

     jack	     CSNETS = ALL

     The user jack may run any command on the machines in the CSNETS alias
     (the networks 128.138.243.0, 128.138.204.0, and 128.138.242.0).  Of those
     networks, only 128.138.204.0 has an explicit netmask (in CIDR notation)
     indicating it is a class C network.  For the other networks in CSNETS,
     the local machine's netmask will be used during matching.

     lisa	     CUNETS = ALL

     The user lisa may run any command on any host in the CUNETS alias (the
     class B network 128.138.0.0).

     operator	     ALL = DUMPS, KILL, SHUTDOWN, HALT, REBOOT, PRINTING,\
		     sudoedit /etc/printcap, /usr/oper/bin/

     The operator user may run commands limited to simple maintenance.	Here,
     those are commands related to backups, killing processes, the printing
     system, shutting down the system, and any commands in the directory
     /usr/oper/bin/.

     joe	     ALL = /usr/bin/su operator

     The user joe may only su(1) to operator.

     pete	     HPPA = /usr/bin/passwd [A-Za-z]*, !/usr/bin/passwd root

     %opers	     ALL = (: ADMINGRP) /usr/sbin/

     Users in the opers group may run commands in /usr/sbin/ as themselves
     with any group in the ADMINGRP Runas_Alias (the adm and oper groups).

     The user pete is allowed to change anyone's password except for root on
     the HPPA machines.	 Note that this assumes passwd(1) does not take multi-
     ple user names on the command line.

     bob	     SPARC = (OP) ALL : SGI = (OP) ALL

     The user bob may run anything on the SPARC and SGI machines as any user
     listed in the OP Runas_Alias (root and operator.)

     jim	     +biglab = ALL

     The user jim may run any command on machines in the biglab netgroup.
     sudo knows that ``biglab'' is a netgroup due to the `+' prefix.

     +secretaries    ALL = PRINTING, /usr/bin/adduser, /usr/bin/rmuser

     Users in the secretaries netgroup need to help manage the printers as
     well as add and remove users, so they are allowed to run those commands
     on all machines.

     fred	     ALL = (DB) NOPASSWD: ALL

     The user fred can run commands as any user in the DB Runas_Alias (oracle
     or sybase) without giving a password.

     john	     ALPHA = /usr/bin/su [!-]*, !/usr/bin/su *root*

     On the ALPHA machines, user john may su to anyone except root but he is
     not allowed to specify any options to the su(1) command.

     jen	     ALL, !SERVERS = ALL

     The user jen may run any command on any machine except for those in the
     SERVERS Host_Alias (master, mail, www and ns).

     jill	     SERVERS = /usr/bin/, !SU, !SHELLS

     For any machine in the SERVERS Host_Alias, jill may run any commands in
     the directory /usr/bin/ except for those commands belonging to the SU and
     SHELLS Cmnd_Aliases.

     steve	     CSNETS = (operator) /usr/local/op_commands/

     The user steve may run any command in the directory /usr/local/op_com-
     mands/ but only as user operator.

     matt	     valkyrie = KILL

     On his personal workstation, valkyrie, matt needs to be able to kill hung
     processes.

     WEBMASTERS	     www = (www) ALL, (root) /usr/bin/su www

     On the host www, any user in the WEBMASTERS User_Alias (will, wendy, and
     wim), may run any command as user www (which owns the web pages) or sim-
     ply su(1) to www.

     ALL	     CDROM = NOPASSWD: /sbin/umount /CDROM,\
		     /sbin/mount -o nosuidnodev /dev/cd0a /CDROM

     Any user may mount or unmount a CD-ROM on the machines in the CDROM
     Host_Alias (orion, perseus, hercules) without entering a password.	 This
     is a bit tedious for users to type, so it is a prime candidate for encap-
     sulating in a shell script.

SECURITY NOTES
   Limitations of the `!' operator
     It is generally not effective to ``subtract'' commands from ALL using the
     `!' operator.  A user can trivially circumvent this by copying the
     desired command to a different name and then executing that.  For exam-
     ple:

     bill    ALL = ALL, !SU, !SHELLS

     Doesn't really prevent bill from running the commands listed in SU or
     SHELLS since he can simply copy those commands to a different name, or
     use a shell escape from an editor or other program.  Therefore, these
     kind of restrictions should be considered advisory at best (and rein-
     forced by policy).

     In general, if a user has sudo ALL there is nothing to prevent them from
     creating their own program that gives them a root shell (or making their
     own copy of a shell) regardless of any `!' elements in the user specifi-
     cation.

   Security implications of fast_glob
     If the fast_glob option is in use, it is not possible to reliably negate
     commands where the path name includes globbing (aka wildcard) characters.
     This is because the C library's fnmatch(3) function cannot resolve rela-
     tive paths.  While this is typically only an inconvenience for rules that
     grant privileges, it can result in a security issue for rules that sub-
     tract or revoke privileges.

     For example, given the following sudoers entry:

     john    ALL = /usr/bin/passwd [a-zA-Z0-9]*, /usr/bin/chsh [a-zA-Z0-9]*,\
		   /usr/bin/chfn [a-zA-Z0-9]*, !/usr/bin/* root

     User john can still run /usr/bin/passwd root if fast_glob is enabled by
     changing to /usr/bin and running ./passwd root instead.

   Preventing shell escapes
     Once sudo executes a program, that program is free to do whatever it
     pleases, including run other programs.  This can be a security issue
     since it is not uncommon for a program to allow shell escapes, which lets
     a user bypass sudo's access control and logging.  Common programs that
     permit shell escapes include shells (obviously), editors, paginators,
     mail and terminal programs.

     There are two basic approaches to this problem:

     restrict  Avoid giving users access to commands that allow the user to
	       run arbitrary commands.	Many editors have a restricted mode
	       where shell escapes are disabled, though sudoedit is a better
	       solution to running editors via sudo.  Due to the large number
	       of programs that offer shell escapes, restricting users to the
	       set of programs that do not is often unworkable.

     noexec    Many systems that support shared libraries have the ability to
	       override default library functions by pointing an environment
	       variable (usually LD_PRELOAD) to an alternate shared library.
	       On such systems, sudo's noexec functionality can be used to
	       prevent a program run by sudo from executing any other pro-
	       grams.  Note, however, that this applies only to native dynami-
	       cally-linked executables.  Statically-linked executables and
	       foreign executables running under binary emulation are not
	       affected.

	       The noexec feature is known to work on SunOS, Solaris, *BSD,
	       Linux, IRIX, Tru64 UNIX, MacOS X, HP-UX 11.x and AIX 5.3 and
	       above.  It should be supported on most operating systems that
	       support the LD_PRELOAD environment variable.  Check your oper-
	       ating system's manual pages for the dynamic linker (usually
	       ld.so, ld.so.1, dyld, dld.sl, rld, or loader) to see if
	       LD_PRELOAD is supported.

	       To enable noexec for a command, use the NOEXEC tag as docu-
	       mented in the User Specification section above.	Here is that
	       example again:

	       aaron   shanty = NOEXEC: /usr/bin/more, /usr/bin/vi

	       This allows user aaron to run /usr/bin/more and /usr/bin/vi
	       with noexec enabled.  This will prevent those two commands from
	       executing other commands (such as a shell).  If you are unsure
	       whether or not your system is capable of supporting noexec you
	       can always just try it out and check whether shell escapes work
	       when noexec is enabled.

     Note that restricting shell escapes is not a panacea.  Programs running
     as root are still capable of many potentially hazardous operations (such
     as changing or overwriting files) that could lead to unintended privilege
     escalation.  In the specific case of an editor, a safer approach is to
     give the user permission to run sudoedit.

   Time stamp file checks
     sudoers will check the ownership of its time stamp directory
     (/var/db/sudo by default) and ignore the directory's contents if it is
     not owned by root or if it is writable by a user other than root.	On
     systems that allow non-root users to give away files via chown(2), if the
     time stamp directory is located in a world-writable directory (e.g.,
     /tmp), it is possible for a user to create the time stamp directory
     before sudo is run.  However, because sudoers checks the ownership and
     mode of the directory and its contents, the only damage that can be done
     is to ``hide'' files by putting them in the time stamp dir.  This is
     unlikely to happen since once the time stamp dir is owned by root and
     inaccessible by any other user, the user placing files there would be
     unable to get them back out.

     sudoers will not honor time stamps set far in the future.	Time stamps
     with a date greater than current_time + 2 * TIMEOUT will be ignored and
     sudo will log and complain.  This is done to keep a user from creating
     his/her own time stamp with a bogus date on systems that allow users to
     give away files if the time stamp directory is located in a world-
     writable directory.

     On systems where the boot time is available, sudoers will ignore time
     stamps that date from before the machine booted.

     Since time stamp files live in the file system, they can outlive a user's
     login session.  As a result, a user may be able to login, run a command
     with sudo after authenticating, logout, login again, and run sudo without
     authenticating so long as the time stamp file's modification time is
     within 5 minutes (or whatever the timeout is set to in sudoers).  When
     the tty_tickets option is enabled, the time stamp has per-tty granularity
     but still may outlive the user's session.	On Linux systems where the
     devpts filesystem is used, Solaris systems with the devices filesystem,
     as well as other systems that utilize a devfs filesystem that monotoni-
     cally increase the inode number of devices as they are created (such as
     Mac OS X), sudoers is able to determine when a tty-based time stamp file
     is stale and will ignore it.  Administrators should not rely on this fea-
     ture as it is not universally available.

SEE ALSO
     ssh(1), su(1), fnmatch(3), glob(3), mktemp(3), strftime(3),
     sudoers.ldap(5), sudo_plugin(8), sudo(8), visudo(8)

CAVEATS
     The sudoers file should always be edited by the visudo command which
     locks the file and does grammatical checking.  It is imperative that
     sudoers be free of syntax errors since sudo will not run with a syntacti-
     cally incorrect sudoers file.

     When using netgroups of machines (as opposed to users), if you store
     fully qualified host name in the netgroup (as is usually the case), you
     either need to have the machine's host name be fully qualified as
     returned by the hostname command or use the fqdn option in sudoers.

BUGS
     If you feel you have found a bug in sudo, please submit a bug report at
     http://www.sudo.ws/sudo/bugs/

SUPPORT
     Limited free support is available via the sudo-users mailing list, see
     http://www.sudo.ws/mailman/listinfo/sudo-users to subscribe or search the
     archives.

DISCLAIMER
     sudo 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 http://www.sudo.ws/sudo/license.html for com-
     plete details.

Sudo 1.8.6p3			 July 16, 2012			  Sudo 1.8.6p3