sudoers(4)             MAINTENANCE COMMANDS            sudoers(4)


NNNNAAAAMMMMEEEE
       sudoers - list of which users may execute what

DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
       The _s_u_d_o_e_r_s file is composed of two types of entries:
       aliases (basically variables) and user specifications
       (which specify who may run what).  The grammar of _s_u_d_o_e_r_s
       will be described below in Extended Backus-Naur Form
       (EBNF).  Don't despair if you don't know what EBNF is; it
       is fairly simple, and the definitions below are annotated.

       QQQQuuuuiiiicccckkkk gggguuuuiiiiddddeeee ttttoooo EEEEBBBBNNNNFFFF

       EBNF is a concise and exact way of describing the grammar
       of a language.  Each EBNF definition is made up of _p_r_o_d_u_c_
       _t_i_o_n _r_u_l_e_s.  E.g.,

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

       Each _p_r_o_d_u_c_t_i_o_n _r_u_l_e references others and thus makes up a
       grammar for the language.  EBNF also contains the follow
       ing operators, which many readers will recognize from reg
       ular expressions.  Do not, however, confuse them with
       "wildcard" characters, which have different meanings.

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

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

       +       Means that the preceding symbol (or group of sym
               bols) 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).

       AAAAlllliiiiaaaasssseeeessss

       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




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        Host_Alias ::= NAME '=' Host_List

        Cmnd_Alias ::= NAME '=' Cmnd_List

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

       Each _a_l_i_a_s definition is of the form

        Alias_Type NAME = item1, item2, ...

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

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

       The definitions of what constitutes a valid _a_l_i_a_s member
       follow.

        User_List ::= User |
                      User ',' User_List

        User ::= '!'* username |
                 '!'* '%'group |
                 '!'* '+'netgroup |
                 '!'* User_Alias

       A User_List is made up of one or more usernames, uids
       (prefixed with '#'), System groups (prefixed with '%'),
       netgroups (prefixed with '+') and other aliases.  Each
       list item may be prefixed with one or more '!' operators.
       An odd number of '!' operators negate the value of the
       item; an even number just cancel each other out.

        Runas_List ::= Runas_User |
                       Runas_User ',' Runas_List

        Runas_User ::= '!'* username |
                       '!'* '#'uid |
                       '!'* '%'group |
                       '!'* +netgroup |
                       '!'* Runas_Alias

       A Runas_List is similar to a User_List except that it can
       also contain uids (prefixed with '#') and instead of
       User_Aliases it can contain Runas_Aliases.

        Host_List ::= Host |
                      Host ',' Host_List





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

       A Host_List is made up of one or more hostnames, IP
       addresses, network numbers, netgroups (prefixed with '+')
       and other aliases.  Again, the value of an item may be
       negated with the '!' operator.  If you do not specify a
       netmask with a network number, the netmask of the host's
       ethernet _i_n_t_e_r_f_a_c_e(s) will be used when matching.  The
       netmask may be specified either in dotted quad notation
       (e.g.  255.255.255.0) or CIDR notation (number of bits,
       e.g. 24).  A hostname may include shell-style wildcards
       (see `Wildcards' section below), but unless the hostname
       command on your machine returns the fully qualified host
       name, you'll need to use the _f_q_d_n option for wildcards to
       be useful.

        Cmnd_List ::= Cmnd |
                      Cmnd ',' Cmnd_List

        commandname ::= filename |
                        filename args |
                        filename '""'

        Cmnd ::= '!'* commandname |
                 '!'* directory |
                 '!'* Cmnd_Alias

       A Cmnd_List is a list of one or more commandnames, direc
       tories, and other aliases.  A commandname is a fully qual
       ified filename which may include shell-style wildcards
       (see `Wildcards' section below).  A simple filename allows
       the user to run the command with any arguments he/she
       wishes.  However, you may also specify command line argu
       ments (including wildcards).  Alternately, you can specify
       "" to indicate that the command may only be run wwwwiiiitttthhhhoooouuuutttt
       command line arguments.  A directory is a fully qualified
       pathname 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 subdirectories 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 argu
       ments: ',', ':', '=', '\'.







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       DDDDeeeeffffaaaauuuullllttttssss

       Certain configuration options may be changed from their
       default values at runtime via one or more Default_Entry
       lines.  These may affect all users on any host, all users
       on a specific host, or just a specific user.  When multi
       ple entries match, they are applied in order.  Where there
       are conflicting values, the last value on a matching line
       takes effect.

        Default_Type ::= 'Defaults' ||
                         'Defaults' ':' User ||
                         'Defaults' '@' Host

        Default_Entry ::= Default_Type Parameter_List

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

       Parameters may be ffffllllaaaaggggssss, iiiinnnntttteeeeggggeeeerrrr values, ssssttttrrrriiiinnnnggggssss, or
       lllliiiissssttttssss.  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 dis
       able 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.

       Note that since the _s_u_d_o_e_r_s file is parsed in order the
       best place to put the Defaults section is after the Host,
       User, and Cmnd aliases but before the user specifications.

       FFFFllllaaaaggggssss:

       long_otp_prompt
                   When validating with a One Time Password
                   scheme (SSSS////KKKKeeeeyyyy or OOOOPPPPIIIIEEEE), 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 _o_f_f by default.

       ignore_dot  If set, ssssuuuuddddoooo will ignore '.' or '' (current
                   dir) in the PATH environment variable; the
                   PATH itself is not modified.  This flag is _o_f_f
                   by default.





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       mail_always Send mail to the _m_a_i_l_t_o user every time a
                   users runs ssssuuuuddddoooo.  This flag is _o_f_f by default.

       mail_badpass
                   Send mail to the _m_a_i_l_t_o user if the user run
                   ning sudo does not enter the correct password.
                   This flag is _o_f_f by default.

       mail_no_user
                   If set, mail will be sent to the _m_a_i_l_t_o user
                   if the invoking user is not in the _s_u_d_o_e_r_s
                   file.  This flag is _o_n by default.

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

       mail_no_perms
                   If set, mail will be sent to the _m_a_i_l_t_o user
                   if the invoking user allowed to use ssssuuuuddddoooo but
                   the command they are trying is not listed in
                   their _s_u_d_o_e_r_s file entry.  This flag is _o_f_f by
                   default.

       tty_tickets If set, users must authenticate on a per-tty
                   basis.  Normally, ssssuuuuddddoooo uses a directory in the
                   ticket dir with the same name as the user run
                   ning it.  With this flag enabled, ssssuuuuddddoooo will
                   use a file named for the tty the user is
                   logged in on in that directory.  This flag is
                   _o_f_f by default.

       lecture     If set, a user will receive a short lecture
                   the first time he/she runs ssssuuuuddddoooo.  This flag is
                   _o_n 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 _o_n by default.

       root_sudo   If set, root is allowed to run ssssuuuuddddoooo too.  Dis
                   abling this prevents users from "chaining"
                   ssssuuuuddddoooo commands to get a root shell by doing
                   something like "sudo sudo /bin/sh".  This flag
                   is _o_n by default.

       log_host    If set, the hostname will be logged in the
                   (non-syslog) ssssuuuuddddoooo log file.  This flag is _o_f_f



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                   by default.

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

       shell_noargs
                   If set and ssssuuuuddddoooo is invoked with no arguments
                   it acts as if the ----ssss flag 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 _o_f_f by default.

       set_home    If set and ssssuuuuddddoooo is invoked with the ----ssss flag
                   the HOME environment variable will be set to
                   the home directory of the target user (which
                   is root unless the ----uuuu option is used).  This
                   effectively makes the ----ssss flag imply ----HHHH.  This
                   flag is _o_f_f by default.

       always_set_home
                   If set, ssssuuuuddddoooo will set the HOME environment
                   variable to the home directory of the target
                   user (which is root unless the ----uuuu option is
                   used).  This effectively means that the ----HHHH
                   flag is always implied.  This flag is _o_f_f by
                   default.

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

       preserve_groups
                   By default ssssuuuuddddoooo will initialize the group vec
                   tor to the list of groups the target user is
                   in.  When _p_r_e_s_e_r_v_e___g_r_o_u_p_s 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 _o_f_f by default.

       fqdn        Set this flag if you want to put fully quali
                   fied hostnames in the _s_u_d_o_e_r_s file.  I.e.:
                   instead of myhost you would use myhost.mydo
                   main.edu.  You may still use the short form if



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sudoers(4)             MAINTENANCE COMMANDS            sudoers(4)


                   you wish (and even mix the two).  Beware that
                   turning on _f_q_d_n requires ssssuuuuddddoooo to make DNS
                   lookups which may make ssssuuuuddddoooo unusable if DNS
                   stops working (for example if the machine is
                   not plugged into the network).  Also note that
                   you must use the host's official 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.  If your machine's hostname
                   (as returned by the hostname command) is
                   already fully qualified you shouldn't need to
                   set _f_q_d_n.  This flag is _o_f_f by default.

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

       requiretty  If set, ssssuuuuddddoooo will only run when the user is
                   logged in to a real tty.  This will disallow
                   things like "rsh somehost sudo ls" since
                   _r_s_h(1) does not allocate a tty.  Because it is
                   not possible to turn of echo when there is no
                   tty present, some sites may with to set this
                   flag to prevent a user from entering a visible
                   password.  This flag is _o_f_f by default.

       env_editor  If set, vvvviiiissssuuuuddddoooo will use the value of the EDI
                   TOR 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.  vvvviiiissssuuuuddddoooo will then only
                   use the EDITOR or VISUAL if they match a value
                   specified in editor.  This flag is off by
                   default.

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

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

       targetpw    If set, ssssuuuuddddoooo will prompt for the password of
                   the user specified by the ----uuuu flag (defaults to
                   root) instead of the password of the invoking
                   user.  This flag is _o_f_f by default.




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       set_logname Normally, ssssuuuuddddoooo will set the LOGNAME and USER
                   environment variables to the name of the tar
                   get user (usually root unless the ----uuuu flag is
                   given).  However, since some programs (includ
                   ing the RCS revision control system) use LOG
                   NAME 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.

       stay_setuid Normally, when ssssuuuuddddoooo 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 ssssuuuuddddoooo act as a setuid wrapper.  This
                   can be useful on systems that disable some
                   potentially dangerous functionality when a
                   program is run setuid.  Note, however, that
                   this means that sudo will run with the real
                   uid of the invoking user which may allow that
                   user to kill ssssuuuuddddoooo before it can log a failure,
                   depending on how your OS defines the interac
                   tion between signals and setuid processes.

       env_reset   If set, ssssuuuuddddoooo will reset the environment to
                   only contain the following variables: HOME,
                   LOGNAME, PATH, SHELL, TERM, and USER (in addi
                   tion to the SUDO_* variables).  Of these, only
                   TERM is copied unaltered from the old environ
                   ment.  The other variables are set to default
                   values (possibly modified by the value of the
                   _s_e_t___l_o_g_n_a_m_e option).  If ssssuuuuddddoooo was compiled
                   with the SECURE_PATH option, its value will be
                   used for the PATH environment variable.  Other
                   variables may be preserved with the _e_n_v___k_e_e_p
                   option.

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

       IIIInnnntttteeeeggggeeeerrrrssss:

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

       IIIInnnntttteeeeggggeeeerrrrssss tttthhhhaaaatttt ccccaaaannnn bbbbeeee uuuusssseeeedddd iiiinnnn aaaa bbbboooooooolllleeeeaaaannnn ccccoooonnnntttteeeexxxxtttt:




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       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).

       timestamp_timeout
                   Number of minutes that can elapse before ssssuuuuddddoooo
                   will ask for a passwd again.  The default is
                   5.  Set this to 0 to always prompt for a pass
                   word.  If set to a value less than 0 the
                   user's timestamp will never expire.  This can
                   be used to allow users to create or delete
                   their own timestamps via sudo -v and sudo -k
                   respectively.

       passwd_timeout
                   Number of minutes before the ssssuuuuddddoooo password
                   prompt times out.  The default is 5, set this
                   to 0 for no password timeout.

       umask       Umask to use when running the command.  Negate
                   this option or set it to 0777 to preserve the
                   user's umask.  The default is 0022.

       SSSSttttrrrriiiinnnnggggssss:

       mailsub     Subject of the mail sent to the _m_a_i_l_t_o user.
                   The escape %h will expand to the hostname of
                   the machine.  Default is *** SECURITY informa
                   tion for %h ***.

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

       timestampdir
                   The directory in which ssssuuuuddddoooo stores its times
                   tamp files.  The default is _/_v_a_r_/_r_u_n_/_s_u_d_o.

       passprompt  The default prompt to use when asking for a
                   password; can be overridden via the ----pppp option
                   or the SUDO_PROMPT environment variable. Sup
                   ports two escapes: "%u" expands to the user's
                   login name and "%h" expands to the local host
                   name.  The default value is Password:.

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




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       syslog_goodpri
                   Syslog priority to use when user authenticates
                   successfully.  Defaults to notice.

       syslog_badpri
                   Syslog priority to use when user authenticates
                   unsuccessfully.  Defaults to alert.

       editor      A colon (':') separated list of editors
                   allowed to be used with vvvviiiissssuuuuddddoooo.  vvvviiiissssuuuuddddoooo will
                   choose the editor that matches the user's USER
                   environment variable if possible, or the first
                   editor in the list that exists and is exe
                   cutable.  The default is the path to vi on
                   your system.

       SSSSttttrrrriiiinnnnggggssss tttthhhhaaaatttt ccccaaaannnn bbbbeeee uuuusssseeeedddd iiiinnnn aaaa bbbboooooooolllleeeeaaaannnn ccccoooonnnntttteeeexxxxtttt:

       logfile     Path to the ssssuuuuddddoooo log file (not the syslog log
                   file).  Setting a path turns on logging to a
                   file; negating this option turns it off.

       syslog      Syslog facility if syslog is being used for
                   logging (negate to disable syslog logging).
                   Defaults to local2.

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

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

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

       exempt_group
                   Users in this group are exempt from password
                   and PATH requirements.  This is not set by
                   default.

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

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

                   any     At least one of the user's _s_u_d_o_e_r_s
                           entries for the current host must have
                           the NOPASSWD flag set to avoid



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                           entering a password.

                   never   The user need never enter a password
                           to use the ----vvvv flag.

                   always  The user must always enter a password
                           to use the ----vvvv flag.

                   The default value is `all'.

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

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

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

                   never   The user need never enter a password
                           to use the ----llll flag.

                   always  The user must always enter a password
                           to use the ----llll flag.

                   The default value is `any'.

       LLLLiiiissssttttssss tttthhhhaaaatttt ccccaaaannnn bbbbeeee uuuusssseeeedddd iiiinnnn aaaa bbbboooooooolllleeeeaaaannnn ccccoooonnnntttteeeexxxxtttt:

       env_check   Environment variables to be removed from the
                   user's environment if the variable's value
                   contains % or / characters.  This can be used
                   to guard against printf-style format vulnera
                   bilties in poorly-written programs.  The argu
                   ment may be a double-quoted, space-separated
                   list or a single value without double-quotes.
                   The list can be replaced, added to, deleted
                   from, or disabled by using the =, +=, -=, and
                   ! operators respectively.  The default list of
                   environment variable to check is printed when
                   ssssuuuuddddoooo is run by root with the _-_V option.

       env_delete  Environment variables to be removed from the
                   user's environment.  The argument may be a
                   double-quoted, space-separated list or a sin
                   gle value without double-quotes.  The list can
                   be replaced, added to, deleted from, or dis
                   abled by using the =, +=, -=, and ! operators
                   respectively.  The default list of environment
                   variable to remove is printed when ssssuuuuddddoooo is run



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                   by root with the _-_V option.

       env_keep    Environment variables to be preserved in the
                   user's environment when the _e_n_v___r_e_s_e_t option
                   is in effect.  This allows fine-grained con
                   trol over the environment ssssuuuuddddoooo-spawned pro
                   cesses will receive.  The argument may be a
                   double-quoted, space-separated list or a sin
                   gle value without double-quotes.  The list can
                   be replaced, added to, deleted from, or dis
                   abled by using the =, +=, -=, and ! operators
                   respectively.  This list has no default mem
                   bers.

       When logging via _s_y_s_l_o_g(3), ssssuuuuddddoooo accepts the following
       values for the syslog facility (the value of the ssssyyyysssslllloooogggg
       Parameter): aaaauuuutttthhhhpppprrrriiiivvvv (if your OS supports it), aaaauuuutttthhhh, ddddaaaaeeee
       mmmmoooonnnn, uuuusssseeeerrrr, llllooooccccaaaallll0000, llllooooccccaaaallll1111, llllooooccccaaaallll2222, llllooooccccaaaallll3333, llllooooccccaaaallll4444, llllooooccccaaaallll5555,
       llllooooccccaaaallll6666, and llllooooccccaaaallll7777.  The following syslog priorities are
       supported: aaaalllleeeerrrrtttt, ccccrrrriiiitttt, ddddeeeebbbbuuuugggg, eeeemmmmeeeerrrrgggg, eeeerrrrrrrr, iiiinnnnffffoooo, nnnnoooottttiiiicccceeee,
       and wwwwaaaarrrrnnnniiiinnnngggg.

       UUUUsssseeeerrrr SSSSppppeeeecccciiiiffffiiiiccccaaaattttiiiioooonnnn

        User_Spec ::= User_list Host_List '=' Cmnd_Spec_List \
                      (':' User_Spec)*

        Cmnd_Spec_List ::= Cmnd_Spec |
                           Cmnd_Spec ',' Cmnd_Spec_List

        Cmnd_Spec ::= Runas_Spec? ('NOPASSWD:' | 'PASSWD:')? Cmnd

        Runas_Spec ::= '(' Runas_List ')'

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

       Let's break that down into its constituent parts:

       RRRRuuuunnnnaaaassss____SSSSppppeeeecccc

       A Runas_Spec is simply a Runas_List (as defined above)
       enclosed in a set of parentheses.  If you do not specify a
       Runas_Spec in the user specification, a default Runas_Spec
       of rrrrooooooootttt will be used.  A Runas_Spec sets the default for
       commands that follow it.  What this means is that for the
       entry:

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

       The user ddddggggbbbb may run _/_b_i_n_/_l_s, _/_b_i_n_/_k_i_l_l, and _/_u_s_r_/_b_i_n_/_l_p_r_m
       -- but only as ooooppppeeeerrrraaaattttoooorrrr.  E.g.,



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sudoers(4)             MAINTENANCE COMMANDS            sudoers(4)


           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 ddddggggbbbb is now allowed to run _/_b_i_n_/_l_s as ooooppppeeeerrrraaaattttoooorrrr,
       but  _/_b_i_n_/_k_i_l_l and _/_u_s_r_/_b_i_n_/_l_p_r_m as rrrrooooooootttt.

       NNNNOOOOPPPPAAAASSSSSSSSWWWWDDDD aaaannnndddd PPPPAAAASSSSSSSSWWWWDDDD

       By default, ssssuuuuddddoooo 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 rrrraaaayyyy to run _/_b_i_n_/_k_i_l_l, _/_b_i_n_/_l_s, and
       _/_u_s_r_/_b_i_n_/_l_p_r_m as root on the machine rushmore as rrrrooooooootttt
       without authenticating himself.  If we only want rrrraaaayyyy to be
       able to run _/_b_i_n_/_k_i_l_l 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 per
       tain to the current host.  This behavior may be overridden
       via the verifypw and listpw options.

       WWWWiiiillllddddccccaaaarrrrddddssss ((((aaaakkkkaaaa mmmmeeeettttaaaa cccchhhhaaaarrrraaaacccctttteeeerrrrssss))))::::

       ssssuuuuddddoooo allows shell-style _w_i_l_d_c_a_r_d_s to be used in pathnames
       as well as command line arguments in the _s_u_d_o_e_r_s file.
       Wildcard matching is done via the PPPPOOOOSSSSIIIIXXXX fnmatch(3) rou
       tine.  Note that these are _n_o_t regular expressions.

       *       Matches any set of zero or more characters.

       ?       Matches any single character.

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





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

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

       Note that a forward slash ('/') will nnnnooootttt be matched by
       wildcards used in the pathname.  When matching the command
       line arguments, however, as slash ddddooooeeeessss get matched by
       wildcards.  This is to make a path like:

           /usr/bin/*

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

       EEEExxxxcccceeeeppppttttiiiioooonnnnssss ttttoooo wwwwiiiillllddddccccaaaarrrrdddd rrrruuuulllleeeessss::::

       The following exceptions apply to the above rules:

       """"    If the empty string "" is the only command line
               argument in the _s_u_d_o_e_r_s entry it means that com
               mand is not allowed to be run with aaaannnnyyyy arguments.

       OOOOtttthhhheeeerrrr ssssppppeeeecccciiiiaaaallll cccchhhhaaaarrrraaaacccctttteeeerrrrssss aaaannnndddd rrrreeeesssseeeerrrrvvvveeeedddd wwwwoooorrrrddddssss::::

       The pound sign ('#') is used to indicate a comment (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 AAAALLLLLLLL is a built in _a_l_i_a_s 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
       _a_l_i_a_s called AAAALLLLLLLL as the built in alias will be used in
       preference to your own.  Please note that using AAAALLLLLLLL can be
       dangerous since in a command context, it allows the user
       to run aaaannnnyyyy command on the system.

       An exclamation point ('!') can be used as a logical _n_o_t
       operator both in an _a_l_i_a_s and in front of a Cmnd.  This
       allows one to exclude certain values.  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.

       Whitespace between elements in a list as well as special
       syntactic characters in a _U_s_e_r _S_p_e_c_i_f_i_c_a_t_i_o_n ('=', ':',
       '(', ')') is optional.




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       The following characters must be escaped with a backslash
       ('\') when used as part of a word (e.g. a username or
       hostname): '@', '!', '=', ':', ',', '(', ')', '\'.

EEEEXXXXAAAAMMMMPPPPLLLLEEEESSSS
       Below are example _s_u_d_o_e_r_s entries.  Admittedly, some of
       these are a bit contrived.  First, we define our _a_l_i_a_s_e_s:

        # 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

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

        # Cmnd alias specification
        Cmnd_Alias     DUMPS = /usr/bin/mt, /usr/sbin/dump, /usr/sbin/rdump,\
                               /usr/sbin/restore, /usr/sbin/rrestore
        Cmnd_Alias     KILL = /usr/bin/kill
        Cmnd_Alias     PRINTING = /usr/sbin/lpc, /usr/bin/lprm
        Cmnd_Alias     SHUTDOWN = /usr/sbin/shutdown
        Cmnd_Alias     HALT = /usr/sbin/halt, /usr/sbin/fasthalt
        Cmnd_Alias     REBOOT = /usr/sbin/reboot, /usr/sbin/fastboot
        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

       Here we override some of the compiled in default values.
       We want ssssuuuuddddoooo to log via _s_y_s_l_o_g(3) using the _a_u_t_h facility
       in all cases.  We don't want to subject the full time
       staff to the ssssuuuuddddoooo lecture, and user mmmmiiiilllllllleeeerrrrtttt need not give
       a password.  In addition, on the machines in the _S_E_R_V_E_R_S
       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.

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



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       The _U_s_e_r _s_p_e_c_i_f_i_c_a_t_i_o_n is the part that actually deter
       mines who may run what.

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

       We let rrrrooooooootttt and any user in group wwwwhhhheeeeeeeellll run any command on
       any host as any user.

        FULLTIMERS     ALL = NOPASSWD: ALL

       Full time sysadmins (mmmmiiiilllllllleeeerrrrtttt, mmmmiiiikkkkeeeeffff, and ddddoooowwwwddddyyyy) may run
       any command on any host without authenticating themselves.

        PARTTIMERS     ALL = ALL

       Part time sysadmins (bbbboooossssttttlllleeeeyyyy, jjjjwwwwffffooooxxxx, and ccccrrrraaaawwwwllll) may run
       any command on any host but they must authenticate them
       selves first (since the entry lacks the NOPASSWD tag).

        jack           CSNETS = ALL

       The user jjjjaaaacccckkkk may run any command on the machines in the
       _C_S_N_E_T_S 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 _C_S_N_E_T_S,
       the local machine's netmask will be used during matching.

        lisa           CUNETS = ALL

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

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

       The ooooppppeeeerrrraaaattttoooorrrr user may run commands limited to simple main
       tenance.  Here, those are commands related to backups,
       killing processes, the printing system, shutting down the
       system, and any commands in the directory _/_u_s_r_/_o_p_e_r_/_b_i_n_/.

        joe            ALL = /usr/bin/su operator

       The user jjjjooooeeee may only _s_u(1) to operator.

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

       The user ppppeeeetttteeee is allowed to change anyone's password
       except for root on the _H_P_P_A machines.  Note that this
       assumes _p_a_s_s_w_d(1) does not take multiple usernames on the
       command line.

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



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sudoers(4)             MAINTENANCE COMMANDS            sudoers(4)


       The user bbbboooobbbb may run anything on the _S_P_A_R_C and _S_G_I
       machines as any user listed in the _O_P Runas_Alias (rrrrooooooootttt
       and ooooppppeeeerrrraaaattttoooorrrr).

        jim            +biglab = ALL

       The user jjjjiiiimmmm may run any command on machines in the _b_i_g_l_a_b
       netgroup.  SSSSuuuuddddoooo knows that "biglab" is a netgroup due to
       the '+' prefix.

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

       Users in the sssseeeeccccrrrreeeettttaaaarrrriiiieeeessss 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 ffffrrrreeeedddd can run commands as any user in the _D_B
       Runas_Alias (oooorrrraaaacccclllleeee or ssssyyyybbbbaaaasssseeee) without giving a password.

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

       On the _A_L_P_H_A machines, user jjjjoooohhhhnnnn may su to anyone except
       root but he is not allowed to give _s_u(1) any flags.

        jen            ALL, !SERVERS = ALL

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

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

       For any machine in the _S_E_R_V_E_R_S Host_Alias, jjjjiiiillllllll may run
       any commands in the directory /usr/bin/ except for those
       commands belonging to the _S_U and _S_H_E_L_L_S Cmnd_Aliases.

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

       The user sssstttteeeevvvveeee may run any command in the directory
       /usr/local/op_commands/ but only as user operator.

        matt           valkyrie = KILL

       On his personal workstation, valkyrie, mmmmaaaatttttttt 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 _W_E_B_M_A_S_T_E_R_S User_Alias
       (will, wendy, and wim), may run any command as user www
       (which owns the web pages) or simply _s_u(1) to www.




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sudoers(4)             MAINTENANCE COMMANDS            sudoers(4)


        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.

SSSSEEEECCCCUUUURRRRIIIITTTTYYYY NNNNOOOOTTTTEEEESSSS
       It is generally not effective to "subtract" commands from
       ALL using the '!' operator.  A user can trivially circum
       vent 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 bbbbiiiillllllll from running the commands
       listed in _S_U or _S_H_E_L_L_S since he can simply copy those com
       mands 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).

CCCCAAAAVVVVEEEEAAAATTTTSSSS
       The _s_u_d_o_e_r_s file should aaaallllwwwwaaaayyyyssss be edited by the vvvviiiissssuuuuddddoooo
       command which locks the file and does grammatical check
       ing. It is imperative that _s_u_d_o_e_r_s be free of syntax
       errors since ssssuuuuddddoooo will not run with a syntactically incor
       rect _s_u_d_o_e_r_s file.

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

FFFFIIIILLLLEEEESSSS
        /etc/sudoers           List of who can run what
        /etc/group             Local groups file
        /etc/netgroup          List of network groups


SSSSEEEEEEEE AAAALLLLSSSSOOOO
       _r_s_h(1), _s_u_d_o(1m), _v_i_s_u_d_o(8), _s_u(1), _f_n_m_a_t_c_h(3).












April 25, 2002                1.6.6                            18