VISUDO(1m) MAINTENANCE COMMANDS VISUDO(1m) NNAAMMEE visudo - edit the sudoers file SSYYNNOOPPSSIISS vviissuuddoo [--cc] [--qq] [--ss] [--VV] [--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 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 the path to _v_i(1) on your system, as determined by the _c_o_n_f_i_g_u_r_e script. 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, _@_s_y_s_c_o_n_f_d_i_r_@_/_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. -q Enable qquuiieett mode. In this mode details about syntax 1.7.0 November 15, 2008 1 VISUDO(1m) MAINTENANCE COMMANDS VISUDO(1m) 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 hostname or username 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 _@_s_y_s_c_o_n_f_d_i_r_@_/_s_u_d_o_e_r_s List of who can run what _@_s_y_s_c_o_n_f_d_i_r_@_/_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 hostname 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. SSEEEE AALLSSOO _v_i(1), _s_u_d_o_e_r_s(4), _s_u_d_o(1m), _v_i_p_w(8) 1.7.0 November 15, 2008 2 VISUDO(1m) MAINTENANCE COMMANDS VISUDO(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. 1.7.0 November 15, 2008 3