VISUDO(1m)                   MAINTENANCE COMMANDS                   VISUDO(1m)



NNAAMMEE
       visudo - edit the sudoers file

SSYYNNOOPPSSIISS
       vviissuuddoo [--cchhqqssVV] [--ff _s_u_d_o_e_r_s]

DDEESSCCRRIIPPTTIIOONN
       vviissuuddoo edits the _s_u_d_o_e_r_s file in a safe fashion, analogous to _v_i_p_w(1m).
       vviissuuddoo locks the _s_u_d_o_e_r_s file against multiple simultaneous edits,
       provides basic sanity checks, and checks for parse errors.  If the
       _s_u_d_o_e_r_s file is currently being edited you will receive a message to
       try again later.

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

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

OOPPTTIIOONNSS
       vviissuuddoo accepts the following command line options:

       -c          Enable cchheecckk--oonnllyy mode.  The existing _s_u_d_o_e_r_s file will be
                   checked for syntax and a message will be printed to the
                   standard output detailing the status of _s_u_d_o_e_r_s.  If the
                   syntax check completes successfully, vviissuuddoo will exit with
                   a value of 0.  If a syntax error is encountered, vviissuuddoo
                   will exit with a value of 1.

       -f _s_u_d_o_e_r_s  Specify and alternate _s_u_d_o_e_r_s file location.  With this
                   option vviissuuddoo will edit (or check) the _s_u_d_o_e_r_s file of your
                   choice, instead of the default, _/_e_t_c_/_s_u_d_o_e_r_s.  The lock
                   file used is the specified _s_u_d_o_e_r_s file with ".tmp"
                   appended to it.  In cchheecckk--oonnllyy mode only, the argument to
                   --ff may be "-", indicating that _s_u_d_o_e_r_s will be read from
                   the standard input.

       -h          The --hh (_h_e_l_p) option causes vviissuuddoo to print a short help
                   message to the standard output and exit.

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

       -s          Enable ssttrriicctt checking of the _s_u_d_o_e_r_s file.  If an alias is
                   used before it is defined, vviissuuddoo will consider this a
                   parse error.  Note that it is not possible to differentiate
                   between an alias and a host name or user name that consists
                   solely of uppercase letters, digits, and the underscore
                   ('_') character.

       -V          The --VV (version) option causes vviissuuddoo to print its version
                   number and exit.

EENNVVIIRROONNMMEENNTT
       The following environment variables may be consulted depending on the
       value of the _e_d_i_t_o_r and _e_n_v___e_d_i_t_o_r _s_u_d_o_e_r_s variables:

       VISUAL          Invoked by visudo as the editor to use

       EDITOR          Used by visudo if VISUAL is not set

FFIILLEESS
       _/_e_t_c_/_s_u_d_o_e_r_s            List of who can run what

       _/_e_t_c_/_s_u_d_o_e_r_s_._t_m_p        Lock file for visudo

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

       /etc/sudoers.tmp: Permission denied
           You didn't run vviissuuddoo as root.

       Can't find you in the passwd database
           Your userid does not appear in the system passwd file.

       Warning: {User,Runas,Host,Cmnd}_Alias referenced but not defined
           Either you are trying to use an undeclare
           {User,Runas,Host,Cmnd}_Alias or you have a user or host name listed
           that consists solely of uppercase letters, digits, and the
           underscore ('_') character.  In the latter case, you can ignore the
           warnings (ssuuddoo will not complain).  In --ss (strict) mode these are
           errors, not warnings.

       Warning: unused {User,Runas,Host,Cmnd}_Alias
           The specified {User,Runas,Host,Cmnd}_Alias was defined but never
           used.  You may wish to comment out or remove the unused alias.  In
           --ss (strict) mode this is an error, not a warning.

       Warning: cycle in {User,Runas,Host,Cmnd}_Alias
           The specified {User,Runas,Host,Cmnd}_Alias includes a reference to
           itself, either directly or through an alias it includes.  This is
           only a warning by default as ssuuddoo will ignore cycles when parsing
           the _s_u_d_o_e_r_s file.

SSEEEE AALLSSOO
       _v_i(1), _s_u_d_o_e_r_s(4), _s_u_d_o(1m), _v_i_p_w(1m)

AAUUTTHHOORR
       Many people have worked on _s_u_d_o over the years; this version of vviissuuddoo
       was written by:

        Todd Miller

       See the HISTORY file in the sudo distribution or visit
       http://www.sudo.ws/sudo/history.html for more details.

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

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

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

DDIISSCCLLAAIIMMEERR
       vviissuuddoo 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 ssuuddoo or
       http://www.sudo.ws/sudo/license.html for complete details.



1.8.3                         September 16, 2011                    VISUDO(1m)
