SUDOERS(4)                    File Formats Manual                   SUDOERS(4)

NAME
     sudoers - default sudo security policy plugin

DESCRIPTION
     The sudoers policy plugin 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
     policy information in LDAP, please see sudoers.ldap(4).

   Configuring sudo.conf for sudoers
     sudo consults the sudo.conf(4) file to determine which policy and and I/O
     logging plugins to load.  If no sudo.conf(4) file is present, or if it
     contains no Plugin lines, sudoers will be used for policy decisions and
     I/O logging.  To explicitly configure sudo.conf(4) to use the sudoers
     plugin, the following configuration can be used.

           Plugin sudoers_policy sudoers.so
           Plugin sudoers_io sudoers.so

     Starting with sudo 1.8.5, it is possible to specify optional arguments to
     the sudoers plugin in the sudo.conf(4) file.  These arguments, if
     present, should be listed after the path to the plugin (i.e. after
     sudoers.so).  Multiple arguments may be specified, separated by white
     space.  For example:

           Plugin sudoers_policy sudoers.so sudoers_mode=0400

     The following plugin arguments are supported:

     ldap_conf=pathname
               The ldap__conf argument can be used to override the default path
               to the ldap.conf file.

     ldap_secret=pathname
               The ldap__secret argument can be used to override the default
               path to the ldap.secret file.

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

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

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

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

     For more information on configuring sudo.conf(4), please refer to its
     manual.

   User Authentication
     The sudoers security policy requires that most users authenticate
     themselves 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
     command.  Unlike su(1), when sudoers requires authentication, it
     validates the invoking user's credentials, not the target user's (or
     root's) credentials.  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 no mail will be sent if an unauthorized user tries to run sudo
     with the -l or -v option unless there is an authentication error and
     either the mail__always or mail__badpass flags are enabled.  This allows
     users to determine for themselves whether or not they are allowed to use
     sudo.  All attempts to run sudo (successful or not) will be logged,
     regardless of whether or not mail is sent.

     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 file lookup is still done for root, not the user specified by
     SUDO_USER.

     sudoers uses per-user time stamp files for credential caching.  Once a
     user has been authenticated, a record is written containing the uid that
     was used to authenticate, the terminal session ID, and a time stamp
     (using a monotonic clock if one is available).  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 separate
     record for each tty, which means that a user's login sessions are
     authenticated separately.  The tty__tickets option can be disabled to
     force the use of a single time stamp for all of a user's sessions.

   Logging
     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.  See LOG FORMAT for a description of the log file format.

     sudoers is also capable of running a command in a pseudo-tty and logging
     all input and/or output.  The standard input, standard output and
     standard error can be logged even when not associated with a terminal.
     I/O logging is not on by default but can be enabled using the log__input
     and log__output options as well as the LOG_INPUT and LOG_OUTPUT command
     tags.  See I/O LOG FILES for details on how I/O log files are stored.

   Command environment
     Since environment variables can influence program behavior, sudoers
     provides 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.  On BSD systems, if the use__loginclass option is
     enabled, the environment is initialized based on the path and setenv
     settings in /etc/login.conf.  The new environment contains the TERM,
     PATH, HOME, MAIL, SHELL, LOGNAME, USER, USERNAME and SUDO_* variables in
     addition to variables from the invoking process permitted by the
     env__check and env__keep options.  This is effectively a whitelist for
     environment variables.  Environment variables with a value beginning with
     () are removed unless both the name and value parts are matched by
     env__keep or env__check, as they will be interpreted as functions by older
     versions of the bash shell.  Prior to version 1.8.11, such variables were
     always removed.

     If, however, the env__reset option is disabled, any variables not
     explicitly 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.  Environment variables with a value beginning with ()
     are always removed, even if they do not match one of the blacklists.
     Since it is not possible to blacklist all potentially dangerous
     environment variables, use of the default env__reset behavior is
     encouraged.

     By default, environment variables are matched by name.  However, if the
     pattern includes an equal sign (`='), both the variables name and value
     must match.  For example, an old-style (pre-shellshock) bash shell
     function could be matched as follows:

         env_keep += "my_func=()*"

     Without the ``=()*'' suffix, this would not match, as old-style bash
     shell functions are not preserved by default.

     The complete list of environment variables that sudo allows or denies is
     contained in the output of ``sudo -V'' when run as root.  Please note
     that this list varies based on the operating system sudo is running on.

     On systems that support PAM where the pam_env module is enabled for sudo,
     variables in the PAM environment may be merged in to the environment.  If
     a variable in the PAM environment is already present in the user's
     environment, the value will only be overridden if the variable was not
     preserved by sudoers.  When env__reset is enabled, variables preserved
     from the invoking user's environment by the env__keep list take precedence
     over those in the PAM environment.  When env__reset is disabled, variables
     present the invoking user's environment take precedence over those in the
     PAM environment unless they match a pattern in the env__delete list.

     Note that the dynamic linker on most operating systems will remove
     variables 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.  On BSD systems, if the use__loginclass flag is enabled,
     the path and setenv variables in /etc/login.conf are also applied.  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
     conflict 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
     necessarily the most specific match).

     The sudoers file grammar will be described below in Extended Backus-Naur
     Form (EBNF).  Don't despair if you are unfamiliar with EBNF; it is fairly
     simple, 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,
     confuse 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
     underscore 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

     It is a syntax error to redefine an existing alias.  It is possible to
     use the same name for aliases of different types, but this is not
     recommended.

     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 `%#'
     respectively), 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.  User netgroups are matched using the user and domain
     members only; the host member is not used when matching.

     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
     characters.  Alternately, special characters may be specified in escaped
     hex mode, e.g. \x20 for space.  When using double quotes, any prefix
     characters must be included inside the quotes.

     The actual nonunix_group and nonunix_gid syntax depends on the underlying
     group provider plugin.  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"

     See GROUP PROVIDER PLUGINS for more information.

     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.  Host netgroups
     are matched using the host (both qualified and unqualified) and domain
     members only; the user member is not used when matching.  If you specify
     a network number without a netmask, sudo will query each of the local
     host's network interfaces and, if the network number corresponds to one
     of the hosts's network interfaces, will use the netmask of that
     interface.  The netmask may be specified either in standard IP address
     notation (e.g. 255.255.255.0 or ffff:ffff:ffff:ff:), 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.

     digest ::= [A-Fa-f0-9]+ |
                [[A-Za-z0-9+/=]+

     Digest_Spec ::= "sha224" ':' digest |
                     "sha256" ':' digest |
                     "sha384" ':' digest |
                     "sha512" ':' digest

     Cmnd_List ::= Cmnd |
                   Cmnd ',' Cmnd_List

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

     Cmnd ::= Digest_Spec? '!'* 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
     simple 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
     characters must be escaped with a `\' if they are used in command
     arguments: `,', `:', `=', `\'.  The built-in command ``sudoedit'' is used
     to permit a user to run sudo with the -e option (or as sudoedit).  It may
     take command line arguments just as a normal command does.  Note that
     ``sudoedit'' is a command built into sudo itself and must be specified in
     the sudoers file without a leading path.

     If a command name is prefixed with a Digest_Spec, the command will only
     match successfully if it can be verified using the specified SHA-2
     digest.  The following digest formats are supported: sha224, sha256,
     sha384 and sha512.  The string may be specified in either hex or base64
     format (base64 is more compact).  There are several utilities capable of
     generating SHA-2 digests in hex format such as openssl, shasum,
     sha224sum, sha256sum, sha384sum, sha512sum.

     For example, using openssl:

     $ openssl dgst -sha224 /bin/ls
     SHA224(/bin/ls)= 118187da8364d490b4a7debbf483004e8f3e053ec954309de2c41a25

     It is also possible to use openssl to generate base64 output:

     $ openssl dgst -binary -sha224 /bin/ls | openssl base64
     EYGH2oNk1JC0p9679IMATo8+BT7JVDCd4sQaJQ==

     Warning, if the user has write access to the command itself (directly or
     via a sudo command), it may be possible for the user to replace the
     command after the digest check has been performed but before the command
     is executed.  A similar race condition exists on systems that lack the
     fexecve(2) system call when the directory in which the command is located
     is writable by the user.

     Command digests are only supported by version 1.8.7 or higher.

   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
     backslash (`\').

     Lists have two additional assignment operators, += and -=.  These
     operators 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? Solaris_Priv_Spec? Tag_Spec* Cmnd

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

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

     Solaris_Priv_Spec ::= ('PRIVS=privset' | 'LIMITPRIVS=privset')

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

     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
     parentheses.  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
     specified, 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 command 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
     setting the group to operator or system.

   SELinux_Spec
     On systems with SELinux support, sudoers file 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.

   Solaris_Priv_Spec
     On Solaris systems, sudoers file entries may optionally specify Solaris
     privilege set and/or limit privilege set associated with a command.  If
     privileges or limit privileges are specified with the command it will
     override any default values specified in sudoers.

     A privilege set is a comma-separated list of privilege names.  The
     ppriv(1) command can be used to list all privileges known to the system.
     For example:

     $ ppriv -l

     In addition, there are several ``special'' privilege strings:

     none      the empty set

     all       the set of all privileges

     zone      the set of all privileges available in the current zone

     basic     the default set of privileges normal users are granted at login
               time

     Privileges can be excluded from a set by prefixing the privilege name
     with either an `!' or `-' character.

   Tag_Spec
     A command may have zero or more tags associated with it.  There are ten
     possible tag values: EXEC, NOEXEC, FOLLOW, NOFOLLOW, LOG_INPUT,
     NOLOG_INPUT, LOG_OUTPUT, NOLOG_OUTPUT, MAIL, NOMAIL, PASSWD, NOPASSWD,
     SETENV, and NOSETENV.  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).

     EXEC and NOEXEC

       If sudo has been compiled with noexec support and the underlying
       operating system supports it, the NOEXEC tag can be used to prevent a
       dynamically-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.

     FOLLOW and NOFOLLOW Starting with version 1.8.15, sudoedit will not open
       a file that is a symbolic link unless the sudoedit__follow option is
       enabled.  The FOLLOW and NOFOLLOW tags override the value of
       sudoedit__follow and can be used to permit (or deny) the editing of
       symbolic links on a per-command basis.  These tags are only effective
       for the sudoedit command and are ignored for all other commands.

     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.

     MAIL and NOMAIL

       These tags provide fine-grained control over whether mail will be sent
       when a user runs a command by overriding the value of the
       mail__all__cmnds option on a per-command basis.  They have no effect when
       sudo is run with the -l or -v options.  A NOMAIL tag will also override
       the mail__always and mail__no__perms options.  For more information, see
       the descriptions of mail__all__cmnds, mail__always, and mail__no__perms in
       the SUDOERS OPTIONS section below.

     PASSWD and NOPASSWD

       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''
       without 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.

     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
       disable the env__reset option from the command line via the -E option.
       Additionally, 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 manner.  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.

   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 glob(3) and fnmatch(3) functions
     as specified by IEEE Std 1003.1 (``POSIX.1'').

     *         Matches any set of zero or more characters (including white
               space).

     ?         Matches any single character (including white space).

     [...]     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 `]'.

     Note that these are not regular expressions.  Unlike a regular expression
     there is no way to match one or more characters within a range.

     Character classes may 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 file name portion of the command.  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.
     Command line arguments are matched as a single, concatenated string.
     This mean a wildcard character such as `?' or `*' will match across word
     boundaries, which may be unexpected.  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.  In most cases it is better to
     do command line processing outside of the sudoers file in a scripting
     language.

   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 file 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
     directives.

     This can be used, for example, to keep a site-wide sudoers file in
     addition to a local, per-machine file.  For the sake of this example the
     site-wide sudoers file 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 sudoers.d directory
     that the system package manager can drop sudoers file 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, but this will not catch the redefinition of an alias that
     is also present in a different file.

   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
     preference 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
     characters 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
     earlier.  A list of all supported Defaults parameters, grouped by type,
     are listed below.

     Boolean Flags:

     always_query_group_plugin
                       If a group__plugin is configured, use it to resolve
                       groups of the form %group as long as there is not also
                       a system group of the same name.  Normally, only groups
                       of the form %:group are passed to the group__plugin.
                       This flag is off by default.

     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 by
                       default, HOME will be set to the home directory of the
                       target user when the env__reset option is enabled, so
                       always__set__home only has an effect for configurations
                       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
                       password (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
                       overrides 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.

     exec_background   By default, sudo runs a command as the foreground
                       process as long as sudo itself is running in the
                       foreground.  When the exec__background flag is enabled
                       and the command is being run in a pty (due to I/O
                       logging or the use__pty flag), the command will be run
                       as a background process.  Attempts to read from the
                       controlling terminal (or to change terminal settings)
                       will result in the command being suspended with the
                       SIGTTIN signal (or SIGTTOU in the case of terminal
                       settings).  If this happens when sudo is a foreground
                       process, the command will be granted the controlling
                       terminal and resumed in the foreground with no user
                       intervention required.  The advantage of initially
                       running the command in the background is that sudo need
                       not read from the terminal unless the command
                       explicitly requests it.  Otherwise, any terminal input
                       must be passed to the command, whether it has required
                       it or not (the kernel buffers terminals so it is not
                       possible to tell whether the command really wants the
                       input).  This is different from historic sudo behavior
                       or when the command is not being run in a pty.

                       For this to work seamlessly, the operating system must
                       support the automatic restarting of system calls.
                       Unfortunately, not all operating systems do this by
                       default, and even those that do may have bugs.  For
                       example, Mac OS X fails to restart the tcgetattr() and
                       tcsetattr() system calls (this is a bug in Mac OS X).
                       Furthermore, because this behavior depends on the
                       command stopping with the SIGTTIN or SIGTTOU signals,
                       programs that catch these signals and suspend
                       themselves with a different signal (usually SIGTOP)
                       will not be automatically foregrounded.  Some versions
                       of the linux su(1) command behave this way.  This flag
                       is off by default.

                       This setting is only supported by version 1.8.7 or
                       higher.  It has no effect unless I/O logging is enabled
                       or the use__pty flag is enabled.

     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
                       security 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.  If the env__reset flag is enabled,
                       the EDITOR and/or VISUAL environment variables must be
                       present in the env__keep list for the env__editor flag to
                       function when visudo is invoked via sudo.  This flag is
                       off by default.

     env_reset         If set, sudo will run the command in a minimal
                       environment 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 contents of the
                       env_keep and env_check lists, as modified by global
                       Defaults parameters in sudoers, 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
                       matching.  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
                       trivially bypassed.  As such, this option should not be
                       used when the sudoers file 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
                       configured 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 host 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
                       network).  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
                       current directory) in the PATH environment variable;
                       the PATH itself is not modified.  This flag is off 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
                       operators 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-
                       syslog) 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
                       connected 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.
                       For more information, see the I/O LOG FILES section.
                       This flag is off by default.

     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.  For more information, see the
                       I/O LOG FILES section.  This flag is off by default.

     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_all_cmnds    Send mail to the mailto user every time a user attempts
                       to run a command via sudo (this includes sudoedit).  No
                       mail will be sent if the user runs sudo with the -l or
                       -v option unless there is an authentication error and
                       the mail__badpass flag is also set.  This flag is off by
                       default.

     mail_always       Send mail to the mailto user every time a user 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__all__cmnds, 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.

     netgroup_tuple    If set, netgroup lookups will be performed using the
                       full netgroup tuple: host name, user name and domain
                       (if one is set).  Historically, sudo only matched the
                       user name and domain for netgroups used in a User_List
                       and only matched the host name and domain for netgroups
                       used in a Host_List.  This flag is off by default.

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

     pam_session       On systems that use PAM for authentication, sudo will
                       create a new PAM session for the command to be run in.
                       Disabling pam__session may be needed on older PAM
                       implementations or on operating systems where opening a
                       PAM session changes the utmp or wtmp files.  If PAM
                       session support is disabled, resource limits may not be
                       updated for the command being run.  If pam__session,
                       pam__setcred, and use__pty are disabled and I/O logging
                       has not been configured, sudo will execute the command
                       directly instead of running it as a child process.
                       This flag is on by default.

                       This setting is only supported by version 1.8.7 or
                       higher.

     pam_setcred       On systems that use PAM for authentication, sudo will
                       attempt to establish credentials for the target user by
                       default, if supported by the underlying authentication
                       system.  One example of a credential is a Kerberos
                       ticket.  If pam__session, pam__setcred, and use__pty are
                       disabled and I/O logging has not been configured, sudo
                       will execute the command directly instead of running it
                       as a child process.  This flag is on by default.

                       This setting is only supported by version 1.8.8 or
                       higher.

     passprompt_override
                       The password prompt specified by passprompt will
                       normally 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.

     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
                       disadvantage 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.

     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
                       vector 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(1m) 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.
                       Disabling 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 when running a
                       command or editing a file.  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 when
                       running a command or editing a file.  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 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 set__logname will have no effect if the
                       env__reset option has not been disabled and the env__keep
                       list contains LOGNAME, USER or USERNAME.  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,
                       environment 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
                       potentially 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.

     sudoedit_checkdir
                       If set, sudoedit will check all directory components of
                       the path to be edited for writability by the invoking
                       user.  Symbolic links will not be followed in writable
                       directories and sudoedit will refuse to edit a file
                       located in a writable directory.  These restrictions
                       are not enforced when sudoedit is run by root.  On some
                       systems, if all directory components of the path to be
                       edited are not readable by the target user, sudoedit
                       will be unable to edit the file.  This flag is on by
                       default.

                       This setting was first introduced in version 1.8.15 but
                       initially suffered from a race condition.  The check
                       for symbolic links in writable intermediate directories
                       was added in version 1.8.16.

     sudoedit_follow   By default, sudoedit will not follow symbolic links
                       when opening files.  The sudoedit__follow option can be
                       enabled to allow sudoedit to open symbolic links.  It
                       may be overridden on a per-command basis by the FOLLOW
                       and NOFOLLOW tags.  This flag is off by default.

                       This setting is only supported by version 1.8.15 or
                       higher.

     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 when running a
                       command or editing a file.  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 separate record
                       in the time stamp file for each tty.  If disabled, a
                       single record is used for all login sessions.  This
                       flag is on by default.

     umask_override    If set, sudo will set the umask as specified in the
                       sudoers file without modification.  This makes it
                       possible to specify a umask in the sudoers file that is
                       more permissive 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.

     use_loginclass    If set, sudo will apply the defaults specified for the
                       target user's login class if one exists.  Only
                       available if sudo is configured with the
                       --with-logincap option.  This flag is off by default.

     use_netgroups     If set, netgroups (prefixed with `+'), may be used in
                       place of a user or host.  For LDAP-based sudoers,
                       netgroup support requires an expensive substring match
                       on the server unless the NETGROUP_BASE directive is
                       present in the /etc/ldap.conf file.  If netgroups are
                       not needed, this option can be disabled to reduce the
                       load on the LDAP server.  This flag is on by default.

     use_pty           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
                       visible 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.

     maxseq            The maximum sequence number that will be substituted
                       for the ``%{seq}'' escape in the I/O log file (see the
                       iolog__dir description above for more information).
                       While the value substituted for ``%{seq}'' is in base
                       36, maxseq itself should be expressed in decimal.
                       Values larger than 2176782336 (which corresponds to the
                       base 36 sequence number `ZZZ') will be silently
                       truncated to 2176782336.  The default value is
                       2176782336.

                       Once the local sequence number reaches the value of
                       maxseq, it will ``roll over'' to zero, after which
                       sudoers will truncate and re-use any existing I/O log
                       path names.

                       This setting is only supported by version 1.8.7 or
                       higher.

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

     Integers that can be used in aa 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
                       insufficient, 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
                       fractional 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 not expire
                       until the system is rebooted.  This can be used to
                       allow users to create or delete their own time stamps
                       via ``sudo -v'' and ``sudo -k'' respectively.

     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
                       lowers 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 or VISUAL environment
                       variable if possible, or the first editor in the list
                       that exists and is executable.  Note that the EDITOR
                       and VISUAL environment variables are not preserved by
                       default when the env__reset option is enabled.  The
                       default is 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
                       supported:

                       %{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
                             command will be run as (e.g. root)

                       %{runas_group}
                             expanded to the group name of the user the
                             command 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
                       system'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.

                       If the path created by concatenating iolog__dir and
                       iolog__file already exists, the existing I/O log file
                       will be truncated and overwritten unless iolog__file
                       ends in six or more Xs.

     lecture_status_dir
                       The directory in which sudo stores per-user lecture
                       status files.  Once a user has received the lecture, a
                       zero-length file is created in this directory so that
                       sudo will not lecture the user again.  This directory
                       should not be cleared when the system reboots.  The
                       default is /var/adm/sudo/lectured.

     limitprivs        The default Solaris limit privileges to use when
                       constructing a new privilege set for a command.  This
                       bounds all privileges of the executing process.  The
                       default limit privileges may be overridden on a per-
                       command basis in sudoers.  This option is only
                       available if sudoers is built on Solaris 10 or higher.

     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       As of sudo version 1.8.1 this option is no longer
                       supported.  The path to the noexec file should now be
                       set in the sudo.conf(4) 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''.  See the description of
                       pam__service for more information.

                       This setting is only supported by version 1.8.8 or
                       higher.

     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''.

                       This setting is only supported by version 1.8.8 or
                       higher.

     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
                             command 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 ``Password:''.

     privs             The default Solaris privileges to use when constructing
                       a new privilege set for a command.  This is passed to
                       the executing process via the inherited privilege set,
                       but is bounded by the limit privileges.  If the privs
                       option is specified but the limitprivs option is not,
                       the limit privileges of the executing process is set to
                       privs.  The default privileges may be overridden on a
                       per-command basis in sudoers.  This option is only
                       available if sudoers is built on Solaris 10 or higher.

     role              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 the sudoers
                       file or via command line options.  This option is only
                       available 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
                       unsuccessfully.  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
                       successfully.  Defaults to notice.

                       See syslog__badpri for the list of supported syslog
                       priorities.

     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.  This directory should be cleared when the
                       system reboots.  The default is /var/run/sudo/ts.

     timestampowner    The owner of the lecture status directory, time stamp
                       directory and all files 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 the sudoers
                       file or via command line options.  This option is only
                       available when sudo is built with SELinux support.

     Strings that can be used in aa 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.  The string should consist of the plugin path,
                   either fully-qualified or relative to the
                   /usr/local/libexec/sudo directory, followed by any
                   configuration arguments the plugin requires.  These
                   arguments (if any) will be passed to the plugin's
                   initialization function.  If arguments are present, the
                   string must be enclosed in double quotes ("").

                   For more information see GROUP PROVIDER PLUGINS.

     lecture       This option controls when a short lecture will be printed
                   along with the password prompt.  It has the following
                   possible 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 file 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 file 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).
                   Setting 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
                   warning and error mail.  The address should be enclosed in
                   double 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
                   environment 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 auth.

                   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 file 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 file 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 aa boolean context:

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

                       +o   It consists of a fully-qualified path name,
                           optionally 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
                           characters.

                       +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
                       aforementioned check.  The global list of environment
                       variables 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
                       global list of environment variables to remove is
                       displayed when sudo is run by root with the -V option.
                       Note that many operating systems will remove
                       potentially 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 global list of
                       variables to keep is displayed when sudo is run by root
                       with the -V option.

GROUP PROVIDER PLUGINS
     The sudoers plugin supports its own plugin interface to allow non-Unix
     group lookups which can query a group source other than the standard Unix
     group database.  This can be used to implement support for the
     nonunix_group syntax described earlier.

     Group provider plugins are specified via the group__plugin Defaults
     setting.  The argument to group__plugin should consist of the plugin path,
     either fully-qualified or relative to the /usr/local/libexec/sudo
     directory, followed by any configuration options the plugin requires.
     These options (if specified) will be passed to the plugin's
     initialization function.  If options are present, the string must be
     enclosed in double quotes ("").

     The following group provider plugins are installed by default:

     group_file
               The group__file plugin supports an alternate group file that
               uses the same syntax as the /etc/group file.  The path to the
               group file should be specified as an option to the plugin.  For
               example, if the group file to be used is /etc/sudo-group:

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

     system_group
               The system__group plugin supports group lookups via the standard
               C library functions getgrnam() and getgrid().  This plugin can
               be used in instances where the user belongs to groups not
               present in the user's supplemental group vector.  This plugin
               takes no options:

               Defaults group_plugin=system_group.so

     The group provider plugin API is described in detail in sudo_plugin(1m).

LOG FORMAT
     sudoers can log events using either syslog(3) or a simple log file.  The
     log format is almost identical in both cases.

   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
                   command'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
        commands 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
        number 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
        setting, 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 the
        sudoers file using group permissions to avoid this problem.  Consider
        either changing the ownership of /etc/sudoers or adding an argument
        like ``sudoers_uid=N'' (where `N' is the user ID that owns the sudoers
        file) to the end of the sudoers Plugin line in the sudo.conf(4) 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
        sudo.conf(4) 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 sudo.conf(4) 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 sudo.conf(4) file.

     unable to open /var/run/sudo/ts/username
        sudoers was unable to read or create the user's time stamp file.  This
        can happen when timestampowner is set to a user other than root and
        the mode on /var/run/sudo is not searchable by group or other.  The
        default mode for /var/run/sudo is 0711.

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

     /var/run/sudo/ts is owned by uid X, should be Y
        The time stamp directory is owned by a user other than timestampowner.
        This can occur when the value of timestampowner has been changed.
        sudoers will ignore the time stamp directory until the owner is
        corrected.

     /var/run/sudo/ts is group writable
        The time stamp directory is group-writable; it should be writable only
        by timestampowner.  The default mode for the time stamp directory is
        0700.  sudoers will ignore the time stamp directory until the mode is
        corrected.

   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 aa 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.

I/O LOG FILES
     When I/O logging is enabled, sudo will run the command in a pseudo-tty
     and log all user input and/or output.  I/O 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 sudo log line, prefixed with
     ``TSID=''.  The iolog__file option may be used to control the format of
     the session ID.

     Each I/O log is stored in a separate directory that contains the
     following files:

     log       a text file containing the time the command was run, the name
               of the user who ran sudo, the name of the target user, the name
               of the target group (optional), the terminal that sudo was run
               from, the number of rows and columns of the terminal, the
               working directory the command was run from and the path name of
               the command itself (with arguments if present)

     timing    a log of the amount of time between, and the number of bytes
               in, each I/O log entry (used for session playback)

     ttyin     input from the user's tty (what the user types)

     stdin     input from a pipe or file

     ttyout    output from the pseudo-tty (what the command writes to the
               screen)

     stdout    standard output to a pipe or redirected to a file

     stderr    standard error to a pipe or redirected to a file

     All files other than log are compressed in gzip format unless the
     compress__io option has been disabled.  Due to buffering, the I/O log data
     will not be complete until the sudo command has completed.  The output
     portion of an I/O log file can be viewed with the sudoreplay(1m) utility,
     which can also be used to list or search the available logs.

     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 unencrypted.  In most cases, logging the command output via
     log__output or LOG_OUTPUT is all that is required.

     Since each session's I/O logs are stored in a separate directory,
     traditional log rotation utilities cannot be used to limit the number of
     I/O logs.  The simplest way to limit the number of I/O is by setting the
     maxseq option to the maximum number of logs you wish to store.  Once the
     I/O log sequence number reaches maxseq, it will be reset to zero and
     sudoers will truncate and re-use any existing I/O logs.

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/run/sudo/ts          Directory containing time stamps for the
                               sudoers security policy

     /var/adm/sudo/lectured    Directory containing lecture status files for
                               the sudoers security policy

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

EXAMPLES
     Below are example sudoers file 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,\
                             sha224:0GomF8mNN3wlDt1HD9XldjJ3SNgpFdbjO1+NsQ== \
                             /home/operator/bin/start_backups
     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).  Note that this will not effectively constrain users with
     sudo ALL privileges.

     # 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/.  Note that one command in the DUMPS Cmnd_Alias includes a
     sha224 digest, /home/operator/bin/start__backups.  This is because the
     directory containing the script is writable by the operator user.  If the
     script is modified (resulting in a digest mismatch) it will no longer be
     possible to run it via sudo.

     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.  Because command line arguments are matched as a
     single, concatenated string, the `*' wildcard will match multiple words.
     This example assumes that passwd(1) does not take multiple user names on
     the command line.  Note that on GNU systems, options to passwd(1) may be
     specified after the user argument.  As a result, this rule will also
     allow:

         passwd username --expire

     which may not be desirable.

     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.  While not specifically mentioned in the rule, the
     commands in the PAGERS Cmnd_Alias all reside in /usr/bin and have the
     noexec option set.

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

     The user steve may run any command in the directory
     /usr/local/op_commands/ 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
     simply su(1) to www.

     ALL             CDROM = NOPASSWD: /sbin/umount /CDROM,\
                     /sbin/mount -o nosuid\,nodev /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
     encapsulating 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
     example:

     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
     reinforced 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
     specification.

   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
     relative paths.  While this is typically only an inconvenience for rules
     that grant privileges, it can result in a security issue for rules that
     subtract or revoke privileges.

     For example, given the following sudoers file 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
               programs.  Note, however, that this applies only to native
               dynamically-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
               operating 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.

               On Solaris 10 and higher, noexec uses Solaris privileges
               instead of the LD_PRELOAD environment variable.

               To enable noexec for a command, use the NOEXEC tag as
               documented 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 (see below).

   Secure editing
     The sudoers plugin includes sudoedit support which allows users to
     securely edit files with the editor of their choice.  As sudoedit is a
     built-in command, it must be specified in the sudoers file without a
     leading path.  However, it may take command line arguments just as a
     normal command does.  Wildcards used in sudoedit command line arguments
     are expected to be path names, so a forward slash (`/') will not be
     matched by a wildcard.

     Unlike other sudo commands, the editor is run with the permissions of the
     invoking user and with the environment unmodified.  More information may
     be found in the description of the -e option in sudo(1m).

     For example, to allow user operator to edit the ``message of the day''
     file:

           operator        sudoedit /etc/motd

     The operator user then runs sudoedit as follows:

           $ sudoedit /etc/motd

     The editor will run as the operator user, not root, on a temporary copy
     of /etc/motd.  After the file has been edited, /etc/motd will be updated
     with the contents of the temporary copy.

     Users should never be granted sudoedit permission to edit a file that
     resides in a directory the user has write access to, either directly or
     via a wildcard.  If the user has write access to the directory it is
     possible to replace the legitimate file with a link to another file,
     allowing the editing of arbitrary files.  To prevent this, starting with
     version 1.8.16, symbolic links will not be followed in writable
     directories and sudoedit will refuse to edit a file located in a writable
     directory unless the sudoedit__checkdir option has been disabled or the
     invoking user is root.  Additionally, in version 1.8.15 and higher,
     sudoedit will refuse to open a symbolic link unless either the
     sudoedit__follow option is enabled or the sudoedit command is prefixed
     with the FOLLOW tag in the sudoers file.

   Time stamp file checks
     sudoers will check the ownership of its time stamp directory
     (/var/run/sudo/ts 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.
     Older versions of sudo stored time stamp files in /tmp; this is no longer
     recommended as it may be possible for a user to create the time stamp
     themselves on systems that allow unprivileged users to change the
     ownership of files they create.

     While the time stamp directory should be cleared at reboot time, not all
     systems contain a /var/run directory.  To avoid potential problems,
     sudoers will ignore time stamp files that date from before the machine
     booted on systems where the boot time is available.

     Some systems with graphical desktop environments allow unprivileged users
     to change the system clock.  Since sudoers relies on the system clock for
     time stamp validation, it may be possible on such systems for a user to
     run sudo for longer than timestamp__timeout by setting the clock back.  To
     combat this, sudoers uses a monotonic clock (which never moves backwards)
     for its time stamps if the system supports it.

     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
     sudoers will log and complain.

     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 record's time stamp is within 5 minutes (or
     whatever value the timeout is set to in the sudoers file).  When the
     tty__tickets option is enabled, the time stamp record includes the device
     number of the terminal the user authenticated with.  This provides per-
     tty granularity but time stamp records still may outlive the user's
     session.  The time stamp record also includes the session ID of the
     process that last authenticated.  This prevents processes in different
     terminal sessions from using the same time stamp record.  It also helps
     reduce the chance that a user will be able to run sudo without entering a
     password when logging out and back in again on the same terminal.

DEBUGGING
     Versions 1.8.4 and higher of the sudoers plugin support a flexible
     debugging framework that can help track down what the plugin is doing
     internally if there is a problem.  This can be configured in the
     sudo.conf(4) file.

     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
     example, a priority of notice would include debug messages logged at
     notice and higher.

     The following subsystems are used by the sudoers plugin:

     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 file Defaults settings

     env       environment handling

     ldap      LDAP-based sudoers

     logging   logging support

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

     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

     sssd      SSSD-based sudoers

     util      utility functions
     For example:

     Debug sudo /var/log/sudo_debug match@info,nss@info

     For more information, see the sudo.conf(4) manual.

SEE ALSO
     ssh(1), su(1), fnmatch(3), glob(3), mktemp(3), strftime(3), sudo.conf(4),
     sudoers.ldap(4), sudo(1m), sudo_plugin(1m), visudo(1m)

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

           Todd C. Miller

     See the CONTRIBUTORS file in the sudo distribution
     (https://www.sudo.ws/contributors.html) for an exhaustive list of people
     who have contributed to sudo.

CAVEATS
     The sudoers file should always be edited by the visudo command which
     locks the file and does grammatical checking.  It is imperative that the
     sudoers file be free of syntax errors since sudo will not run with a
     syntactically 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
     https://bugzilla.sudo.ws/

SUPPORT
     Limited free support is available via the sudo-users mailing list, see
     https://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,
     including, 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 https://www.sudo.ws/license.html for
     complete details.

Sudo 1.8.17                    January 20, 2016                    Sudo 1.8.17
