visudo

 


visudo(8)              MAINTENANCE COMMANDS             visudo(8)



NAME
       visudo - edit the sudoers file

SYNOPSIS
       visudo [ -s ] [ -V ]

DESCRIPTION
       visudo edits the sudoers file in a safe fashion, analogous
       to vipw(8).  visudo locks the sudoers file against
       multiple simultaneous edits, provides 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.  In the default configuration, the vi(1)
       editor is used, but there is a compile time option to
       allow use of whatever editor the environment variables
       EDITOR or VISUAL are set to.

       visudo parses the sudoers file after the edit and will not
       save the changes if there is a syntax error.  Upon finding
       an error, a message will be printed stating the line
       number(s) that the error occurred on and the user will
       receive the "What now?" prompt.  At this point the user
       may enter "e" to re-edit the sudoers file, enter "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 visudo believes there to be a parse error, so
       will sudo and no one will be able to execute sudo again
       until the error is fixed.  Any other command at this
       prompt will print a short help message.  When editing 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).

OPTIONS
       visudo accepts the following command line option:

       -s  Enable strict checking of the sudoers file.  If an
           alias is used before it is defined, visudo 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 upper
           case letters, digits, and the underscore ('_')
           character.

       -V  The -V (version) option causes visudo to print the
           version number and exit.

ERRORS
       sudoers file busy, try again later.
           Someone else is currently editing the sudoers file.

       /etc/sudoers.tmp: Permission denied
           You didn't run visudo 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 upper case letters,
           digits, and the underscore ('_') character.  If the
           latter, you can ignore the warnings  sudo(will not
           complain).  In -s (strict) mode these are errors not
           warnings.

ENVIRONMENT
       The following environment variables are used only if
       visudo was configured with the --with-env-editor option:

        EDITOR                 Used by visudo as the editor to use
        VISUAL                 Used by visudo if EDITOR is not set


FILES
        /etc/sudoers           List of who can run what
        /etc/sudoers.tmp       Lock file for visudo


AUTHOR
       Many people have worked on sudo over the years, this
       version of visudo was written by:

        Todd Miller            <Todd.Miller@courtesan.com>

       See the HISTORY file in the sudo distribution for more
       details.

BUGS
       If you feel you have found a bug in sudo, please submit a
       bug report at http://www.courtesan.com/sudo/bugs/

DISCLAIMER
       Visudo 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 sudo for complete details.

CAVEATS
       There is no easy way to prevent a user from gaining a root
       shell if the editor used by visudo allows shell escapes.

SEE ALSO
       sudo(8), vipw(8).























26/Mar/2000                   1.6.3                     visudo(8)