VISUDO(1m) System Manager's Manual VISUDO(1m) NNAAMMEE vviissuuddoo - 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 vipw(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 --with-env-editor 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). The options are as follows: --cc Enable _c_h_e_c_k_-_o_n_l_y mode. The existing _s_u_d_o_e_r_s file will be checked for syntax errors, owner and mode. A message will be printed to the standard output describing the status of _s_u_d_o_e_r_s unless the --qq option was specified. If the check completes successfully, vviissuuddoo will exit with a value of 0. If an error is encountered, vviissuuddoo will exit with a value of 1. --ff _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 _c_h_e_c_k_-_o_n_l_y mode only, the argument to --ff may be `-', indicating that _s_u_d_o_e_r_s will be read from the standard input. --hh The --hh (_h_e_l_p) option causes vviissuuddoo to print a short help message to the standard output and exit. --qq Enable _q_u_i_e_t mode. In this mode details about syntax errors are not printed. This option is only useful when combined with the --cc option. --ss Enable _s_t_r_i_c_t 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. --VV The --VV (_v_e_r_s_i_o_n) 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 settings: VISUAL Invoked by vviissuuddoo as the editor to use EDITOR Used by vviissuuddoo 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 user ID 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 undeclared {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 vi(1), sudoers(4), sudo(1m), vipw(1m) AAUUTTHHOORRSS Many people have worked on ssuuddoo over the years; this version consists of code written primarily by: Todd C. Miller See the CONTRIBUTORS file in the ssuuddoo distribution (http://www.sudo.ws/sudo/contributors.html) for an exhaustive list of people who have contributed to ssuuddoo. 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. Sudo 1.7.10 July 12, 2012 Sudo 1.7.10