visudo(1m) MAINTENANCE COMMANDS visudo(1m) NNNNAAAAMMMMEEEE visudo - edit the sudoers file SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS vvvviiiissssuuuuddddoooo [ ----cccc ] [ ----ffff _s_u_d_o_e_r_s ] [ ----qqqq ] [ ----ssss ] [ ----VVVV ] DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN vvvviiiissssuuuuddddoooo edits the _s_u_d_o_e_r_s file in a safe fashion, analogous to _v_i_p_w(1m). vvvviiiissssuuuuddddoooo locks the _s_u_d_o_e_r_s file against multi­ ple 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 vvvviiiissssuuuuddddoooo 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, vvvviiiissssuuuuddddoooo does not honor the EDITOR or VISUAL environment variables unless they contain an editor in the aforementioned editors list. However, if vvvviiiissssuuuuddddoooo is configured with the _-_-_w_i_t_h_-_e_n_v_e_d_i_t_o_r flag or the _e_n_v_e_d_i_t_o_r Default variable is set in _s_u_d_o_e_r_s, vvvviiiissssuuuuddddoooo will use any the editor defines by EDITOR or VISUAL. Note that this can be a security hole since it allows the user to execute any program they wish simply by setting EDITOR or VISUAL. vvvviiiissssuuuuddddoooo 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, vvvviiiissssuuuuddddoooo will print a message stating the line _n_u_m_b_e_r(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 vvvviiiissssuuuuddddoooo believes there to be a parse error, so will ssssuuuuddddoooo and no one will be able to ssssuuuuddddoooo 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). OOOOPPPPTTTTIIIIOOOONNNNSSSS vvvviiiissssuuuuddddoooo accepts the following command line options: -c Enable cccchhhheeeecccckkkk----oooonnnnllllyyyy 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, vvvviiiissssuuuuddddoooo will exit with a value of 0. If a syntax error is encountered, vvvviiiissssuuuuddddoooo will exit with a value of 1. -f Specify and alternate _s_u_d_o_e_r_s file location. With this option vvvviiiissssuuuuddddoooo will edit (or check) the _s_u_d_o_e_r_s April 25, 2002 1.6.6 1 visudo(1m) MAINTENANCE COMMANDS visudo(1m) file of your choice, instead of the default, @sysconfdir@/sudoers. The lock file used is the spec­ ified _s_u_d_o_e_r_s file with ".tmp" appended to it. -q Enable qqqquuuuiiiieeeetttt mode. In this mode details about syntax errors are not printed. This option is only useful when combined with the ----cccc flag. -s Enable ssssttttrrrriiiicccctttt checking of the _s_u_d_o_e_r_s file. If an alias is used before it is defined, vvvviiiissssuuuuddddoooo will con­ sider this a parse error. Note that it is not possi­ ble to differentiate between an alias and a hostname or username that consists solely of uppercase letters, digits, and the underscore ('_') character. -V The ----VVVV (version) option causes vvvviiiissssuuuuddddoooo to print its version number and exit. EEEERRRRRRRROOOORRRRSSSS 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 vvvviiiissssuuuuddddoooo as root. Can't find you in the passwd database Your userid does not appear in the system passwd file. Warning: undeclared Alias referenced near ... Either you are using a {User,Runas,Host,Cmnd}_Alias before defining it or you have a user or hostname listed that consists solely of uppercase letters, dig­ its, and the underscore ('_') character. If the lat­ ter, you can ignore the warnings (ssssuuuuddddoooo will not com­ plain). In ----ssss (strict) mode these are errors, not warnings. EEEENNNNVVVVIIIIRRRROOOONNNNMMMMEEEENNNNTTTT The following environment variables are used only if vvvviiiissssuuuuddddoooo was configured with the _-_-_w_i_t_h_-_e_n_v_-_e_d_i_t_o_r option: EDITOR Invoked by visudo as the editor to use VISUAL Used Invoked visudo if EDITOR is not set FFFFIIIILLLLEEEESSSS /etc/sudoers List of who can run what /etc/sudoers.tmp Lock file for visudo AAAAUUUUTTTTHHHHOOOORRRR Many people have worked on _s_u_d_o over the years; this ver­ sion of vvvviiiissssuuuuddddoooo was written by: April 25, 2002 1.6.6 2 visudo(1m) MAINTENANCE COMMANDS visudo(1m) Todd Miller See the HISTORY file in the sudo distribution or visit http://www.sudo.ws/sudo/history.html for more details. BBBBUUUUGGGGSSSS If you feel you have found a bug in sudo, please submit a bug report at http://www.sudo.ws/sudo/bugs/ DDDDIIIISSSSCCCCLLLLAAAAIIIIMMMMEEEERRRR VVVViiiissssuuuuddddoooo 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 ssssuuuuddddoooo for complete details. CCCCAAAAVVVVEEEEAAAATTTTSSSS There is no easy way to prevent a user from gaining a root shell if the editor used by vvvviiiissssuuuuddddoooo allows shell escapes. SSSSEEEEEEEE AAAALLLLSSSSOOOO _v_i(1), _s_u_d_o(1m), _v_i_p_w(8). April 25, 2002 1.6.6 3