NAME
visudo - edit the sudoers file
SYNOPSIS
vviissuuddoo [ -cc ] [ -ff sudoers ] [ -qq ] [ -ss ] [ -VV ]
DESCRIPTION
vviissuuddoo edits the sudoers file in a safe fashion, analogous to vipw(8).vviissuuddoo locks the sudoers file against multiple simultaneous edits, pro-
vides basic sanity checks, and checks for parse errors. If the sudoers 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 com-
pile-time that may be overridden via the editor sudoers Default vari-
able. This list defaults to the path to vi(1) on your system, as determined by the configure script. Normally, vviissuuddoo does not honorthe VISUAL or EDITOR environment variables unless they contain an edi-
tor in the aforementioned editors list. However, if vviissuuddoo is config-
ured with the -with-enveditor flag or the enveditor Default variable
is set in sudoers, 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 sudoers 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 usermay enter "e" to re-edit the sudoers 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 sudoers 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 sudoers file will be checked
for syntax and a message will be printed to the standard output detailing the status of sudoers. 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 Specify and alternate sudoers file location. With this option
vviissuuddoo will edit (or check) the sudoers file of your choice, instead of the default, /private/etc/sudoers. The lock file used is the specified sudoers file with ".tmp" appended to it.-q Enable qquuiieett mode. In this mode details about syntax errors are
not printed. This option is only useful when combined with the -cc
flag.-s Enable ssttrriicctt checking of the sudoers 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. ENVIRONMENTThe following environment variables are used only if vviissuuddoo was config-
ured with the -with-env-editor option:
VISUAL Invoked by visudo as the editor to use
EDITOR Used by visudo if VISUAL is not set
FILES /private/etc/sudoers List of who can run what/private/etc/sudoers.tmp Lock file for visudo
DIAGNOSTICS sudoers file busy, try again later. Someone else is currently editing the sudoers file. /private/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: 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, digits, and the underscore ('') character. If the latter, you can ignore the warnings (ssuuddoo will not complain).In -ss (strict) mode these are errors, not warnings.
Warning: runasdefault set after old value is in use ... You have a runasdefault Defaults setting listed in the sudoers file after its value has already been used. This means that entries prior to the runasdefault setting will match based on the default value of runasdefault (root) whereas entries aafftteerr the runasdefault setting will match based on the new value. This is usually unintentional and in most cases thesetting should be placed before any RunasAlias or User specifications. In -ss (strict) mode this is an error, not a warning.
SEE ALSO
vi(1), sudoers(5), sudo(8), vipw(8) AUTHOR Many people have worked on sudo 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.BUGS
If you feel you have found a bug in vviissuuddoo, please submit a bug report at http://www.sudo.ws/sudo/bugs/ SSUUPPPPOORRTT Commercial support is available for ssuuddoo, see http://www.sudo.ws/sudo/support.html for details.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 merchantabil-
ity 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. 1.6.8p12 June 20, 2005 VISUDO(8)