1VISUDO(8) BSD System Manager's Manual VISUDO(8)
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4 visudo — edit the sudoers file
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7 visudo [-chIOPqsV] [[-f] sudoers]
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10 visudo edits the sudoers file in a safe fashion, analogous to vipw(8).
11 visudo locks the sudoers file against multiple simultaneous edits, per‐
12 forms basic validity checks, and checks for syntax errors before in‐
13 stalling the edited file. If the sudoers file is currently being edited
14 you will receive a message to try again later.
15 visudo parses the sudoers file after editing and will not save the
17 changes if there is a syntax error. Upon finding an error, visudo will
18 print a message stating the line number(s) where the error occurred and
19 the user will receive the “What now?” prompt. At this point the user may
20 enter ‘e’ to re-edit the sudoers file, ‘x’ to exit without saving the
21 changes, or ‘Q’ to quit and save changes. The ‘Q’ option should be used
22 with extreme caution because if visudo believes there to be a syntax er‐
23 ror, so will sudo. If ‘e’ is typed to edit the sudoers file after a syn‐
24 tax error has been detected, the cursor will be placed on the line where
25 the error occurred (if the editor supports this feature).
26 There are two sudoers settings that determine which editor visudo will
28 run.
29 editor A colon (‘:’) separated list of editors allowed to be used with
31 visudo. visudo will choose the editor that matches the user's
32 SUDO_EDITOR, VISUAL, or EDITOR environment variable if possi‐
33 ble, or the first editor in the list that exists and is exe‐
34 cutable. sudo does not preserve the SUDO_EDITOR, VISUAL, or
35 EDITOR environment variables unless they are present in the
36 env_keep list or the env_reset option is disabled in the
37 sudoers file. The default editor path is
38 /usr/bin/nano:/usr/bin/vim:/usr/bin/vi which can be set at com‐
39 pile time via the --with-editor configure option.
40 env_editor
42 If set, visudo will use the value of the SUDO_EDITOR, VISUAL,
43 or EDITOR environment variables before falling back on the de‐
44 fault editor list. visudo is typically run as root so this op‐
45 tion may allow a user with visudo privileges to run arbitrary
46 commands as root without logging. An alternative is to place a
47 colon-separated list of “safe” editors in the editor variable.
48 visudo will then only use SUDO_EDITOR, VISUAL, or EDITOR if
49 they match a value specified in editor. If the env_reset flag
50 is enabled, the SUDO_EDITOR, VISUAL, and/or EDITOR environment
51 variables must be present in the env_keep list for the
52 env_editor flag to function when visudo is invoked via sudo.
53 The default value is on, which can be set at compile time via
54 the --with-env-editor configure option.
55 The options are as follows:
57 -c, --check
59 Enable check-only mode. The existing sudoers file (and any
60 other files it includes) will be checked for syntax errors.
61 If the path to the sudoers file was not specified, visudo
62 will also check the file ownership and permissions (see the
63 -O and -P options). A message will be printed to the stan‐
64 dard output describing the status of sudoers unless the -q
65 option was specified. If the check completes successfully,
66 visudo will exit with a value of 0. If an error is encoun‐
67 tered, visudo will exit with a value of 1.
68 -f sudoers, --file=sudoers
70 Specify an alternate sudoers file location, see below. As of
71 version 1.8.27, the sudoers path can be specified without us‐
72 ing the -f option.
73 -h, --help Display a short help message to the standard output and exit.
75 -I, --no-includes
77 Disable the editing of include files unless there is a pre-
78 existing syntax error. By default, visudo will edit the main
79 sudoers file and any files included via @include or #include
80 directives. Files included via @includedir or #includedir
81 are never edited unless they contain a syntax error.
82 -O, --owner
84 Enforce the default ownership (user and group) of the sudoers
85 file. In edit mode, the owner of the edited file will be set
86 to the default. In check mode (-c), an error will be re‐
87 ported if the owner is incorrect. This option is enabled by
88 default if the sudoers file was not specified.
89 -P, --perms
91 Enforce the default permissions (mode) of the sudoers file.
92 In edit mode, the permissions of the edited file will be set
93 to the default. In check mode (-c), an error will be re‐
94 ported if the file permissions are incorrect. This option is
95 enabled by default if the sudoers file was not specified.
96 -q, --quiet
98 Enable quiet mode. In this mode details about syntax errors
99 are not printed. This option is only useful when combined
100 with the -c option.
101 -s, --strict
103 Enable strict checking of the sudoers file. If an alias is
104 referenced but not actually defined or if there is a cycle in
105 an alias, visudo will consider this a syntax error. It is
106 not possible to differentiate between an alias and a host
107 name or user name that consists solely of uppercase letters,
108 digits, and the underscore (‘_’) character.
109 -V, --version
111 Print the visudo and sudoers grammar versions and exit.
112 A sudoers file may be specified instead of the default, /etc/sudoers.
114 The temporary file used is the specified sudoers file with “.tmp” ap‐
115 pended to it. In check-only mode only, ‘-’ may be used to indicate that
116 sudoers will be read from the standard input. Because the policy is
117 evaluated in its entirety, it is not sufficient to check an individual
118 sudoers include file for syntax errors.
119 Debugging and sudoers plugin arguments
121 visudo versions 1.8.4 and higher support a flexible debugging framework
122 that is configured via Debug lines in the sudo.conf(5) file.
123 Starting with sudo 1.8.12, visudo will also parse the arguments to the
125 sudoers plugin to override the default sudoers path name, user-ID, group-
126 ID, and file mode. These arguments, if present, should be listed after
127 the path to the plugin (i.e., after sudoers.so). Multiple arguments may
128 be specified, separated by white space. For example:
129 Plugin sudoers_policy sudoers.so sudoers_mode=0400
131 The following arguments are supported:
133 sudoers_file=pathname
135 The sudoers_file argument can be used to override the default
136 path to the sudoers file.
137 sudoers_uid=user-ID
139 The sudoers_uid argument can be used to override the default
140 owner of the sudoers file. It should be specified as a numeric
141 user-ID.
142 sudoers_gid=group-ID
144 The sudoers_gid argument can be used to override the default
145 group of the sudoers file. It must be specified as a numeric
146 group-ID (not a group name).
147 sudoers_mode=mode
149 The sudoers_mode argument can be used to override the default
150 file mode for the sudoers file. It should be specified as an
151 octal value.
152 For more information on configuring sudo.conf(5), refer to its manual.
154
156 The following environment variables may be consulted depending on the
157 value of the editor and env_editor sudoers settings:
158 SUDO_EDITOR Invoked by visudo as the editor to use
160 VISUAL Used by visudo if SUDO_EDITOR is not set
162 EDITOR Used by visudo if neither SUDO_EDITOR nor VISUAL is set
164
166 /etc/sudo.conf Sudo front-end configuration
167 /etc/sudoers List of who can run what
169 /etc/sudoers.tmp Default temporary file used by visudo
171
173 In addition to reporting sudoers syntax errors, visudo may produce the
174 following messages:
175 sudoers file busy, try again later.
177 Someone else is currently editing the sudoers file.
178 /etc/sudoers: Permission denied
180 You didn't run visudo as root.
181 you do not exist in the passwd database
183 Your user-ID does not appear in the system passwd database.
184 Warning: {User,Runas,Host,Cmnd}_Alias referenced but not defined
186 Either you are trying to use an undeclared
187 {User,Runas,Host,Cmnd}_Alias or you have a user or host name listed
188 that consists solely of uppercase letters, digits, and the under‐
189 score (‘_’) character. In the latter case, you can ignore the
190 warnings (sudo will not complain). The message is prefixed with
191 the path name of the sudoers file and the line number where the un‐
192 defined alias was used. In -s (strict) mode these are errors, not
193 warnings.
194 Warning: unused {User,Runas,Host,Cmnd}_Alias
196 The specified {User,Runas,Host,Cmnd}_Alias was defined but never
197 used. The message is prefixed with the path name of the sudoers
198 file and the line number where the unused alias was defined. You
199 may wish to comment out or remove the unused alias.
200 Warning: cycle in {User,Runas,Host,Cmnd}_Alias
202 The specified {User,Runas,Host,Cmnd}_Alias includes a reference to
203 itself, either directly or through an alias it includes. The mes‐
204 sage is prefixed with the path name of the sudoers file and the
205 line number where the cycle was detected. This is only a warning
206 unless visudo is run in -s (strict) mode as sudo will ignore cycles
207 when parsing the sudoers file.
208 unknown defaults entry "name"
210 The sudoers file contains a Defaults setting not recognized by
211 visudo.
212
214 vi(1), sudo.conf(5), sudoers(5), sudo(8), vipw(8)
215
217 Many people have worked on sudo over the years; this version consists of
218 code written primarily by:
219 Todd C. Miller
221 See the CONTRIBUTORS.md file in the sudo distribution
223 (https://www.sudo.ws/about/contributors/) for an exhaustive list of peo‐
224 ple who have contributed to sudo.
225
227 There is no easy way to prevent a user from gaining a root shell if the
228 editor used by visudo allows shell escapes.
229
231 If you believe you have found a bug in visudo, you can submit a bug re‐
232 port at https://bugzilla.sudo.ws/
233
235 Limited free support is available via the sudo-users mailing list, see
236 https://www.sudo.ws/mailman/listinfo/sudo-users to subscribe or search
237 the archives.
238
240 visudo is provided “AS IS” and any express or implied warranties, includ‐
241 ing, but not limited to, the implied warranties of merchantability and
242 fitness for a particular purpose are disclaimed. See the LICENSE.md file
243 distributed with sudo or https://www.sudo.ws/about/license/ for complete
244 details.
245Sudo 1.9.12p2 October 4, 2022 Sudo 1.9.12p2