-=cut
-Copyright (c) 1994-1996, 1998-2005, 2007
+Copyright (c) 1994-1996, 1998-2005, 2007-2010
Todd C. Miller <Todd.Miller@courtesan.com>
Permission to use, copy, modify, and distribute this software for any
Agency (DARPA) and Air Force Research Laboratory, Air Force
Materiel Command, USAF, under agreement number F39502-99-1-0512.
-$Sudo: sudo.pod,v 1.70.2.19 2007/11/21 19:26:10 millert Exp $
=pod
=head1 NAME
=head1 SYNOPSIS
-B<sudo> B<-h> | B<-K> | B<-k> | B<-L> | B<-l> | B<-V> | B<-v>
-
-B<sudo> [B<-bEHPS>] S<[B<-a> I<auth_type>]>
-S<[B<-c> I<class>|I<->]> S<[B<-p> I<prompt>]> S<[B<-u> I<username>|I<#uid>]>
-S<[B<VAR>=I<value>]> S<{B<-i> | B<-s> | I<command>}>
-
-B<sudoedit> [B<-S>] S<[B<-a> I<auth_type>]> S<[B<-c> I<class>|I<->]>
-S<[B<-p> I<prompt>]> S<[B<-u> I<username>|I<#uid>]>
-file ...
+B<sudo> B<-h> | B<-K> | B<-k> | B<-L> | B<-V>
+
+B<sudo> B<-v> [B<-AknS>]
+S<[B<-a> I<auth_type>]>
+S<[B<-g> I<group name>|I<#gid>]> S<[B<-p> I<prompt>]>
+S<[B<-u> I<username>|I<#uid>]>
+
+B<sudo> B<-l[l]> [B<-AknS>]
+S<[B<-a> I<auth_type>]>
+S<[B<-g> I<group name>|I<#gid>]> S<[B<-p> I<prompt>]>
+S<[B<-U> I<user name>]> S<[B<-u> I<user name>|I<#uid>]> [I<command>]
+
+B<sudo> [B<-AbEHnPS>]
+S<[B<-a> I<auth_type>]>
+S<[B<-C> I<fd>]>
+S<[B<-c> I<class>|I<->]>
+S<[B<-g> I<group name>|I<#gid>]> S<[B<-p> I<prompt>]>
+S<[B<-r> I<role>]> S<[B<-t> I<type>]>
+S<[B<-u> I<user name>|I<#uid>]>
+S<[B<VAR>=I<value>]> S<[B<-i> | B<-s>]> [I<command>]
+
+B<sudoedit> [B<-AnS>]
+S<[B<-a> I<auth_type>]>
+S<[B<-C> I<fd>]>
+S<[B<-c> I<class>|I<->]>
+S<[B<-g> I<group name>|I<#gid>]> S<[B<-p> I<prompt>]>
+S<[B<-u> I<user name>|I<#uid>]> file ...
=head1 DESCRIPTION
B<sudo> requires that users authenticate themselves with a password
by default (NOTE: in the default configuration this is the user's
password, not the root password). Once a user has been authenticated,
-a timestamp is updated and the user may then use sudo without a
+a time stamp is updated and the user may then use sudo without a
password for a short period of time (C<@timeout@> minutes unless
overridden in I<sudoers>).
is implied.
B<sudo> determines who is an authorized user by consulting the file
-F<@sysconfdir@/sudoers>. By giving B<sudo> the B<-v> flag, a user
-can update the time stamp without running a I<command>. The password
-prompt itself will also time out if the user's password is not
-entered within C<@password_timeout@> minutes (unless overridden via
-I<sudoers>).
+F<@sysconfdir@/sudoers>. By running B<sudo> with the B<-v> option,
+a user can update the time stamp without running a I<command>. If
+a password is required, B<sudo> will exit if the user's password
+is not entered within a configurable time limit. The default
+password prompt timeout is C<@password_timeout@> minutes.
If a user who is not listed in the I<sudoers> file tries to run a
command via B<sudo>, mail is sent to the proper authorities, as
defined at configure time or in the I<sudoers> file (defaults to
C<@mailto@>). Note that the mail will not be sent if an unauthorized
-user tries to run sudo with the B<-l> or B<-v> flags. This allows
+user tries to run sudo with the B<-l> or B<-v> option. This allows
users to determine for themselves whether or not they are allowed
to use B<sudo>.
is set, B<sudo> will use this value to determine who the actual
user is. This can be used by a user to log commands through sudo
even when a root shell has been invoked. It also allows the B<-e>
-flag to remain useful even when being run via a sudo-run script or
+option to remain useful even when being run via a sudo-run script or
program. Note however, that the sudoers lookup is still done for
root, not the user specified by C<SUDO_USER>.
B<sudo> accepts the following command line options:
-=over 4
+=over 12
+
+=item -A
-=item -a
+Normally, if B<sudo> requires a password, it will read it from the
+current terminal. If the B<-A> (I<askpass>) option is specified,
+a (possibly graphical) helper program is executed to read the
+user's password and output the password to the standard output. If
+the C<SUDO_ASKPASS> environment variable is set, it specifies the
+path to the helper program. Otherwise, the value specified by the
+I<askpass> option in L<sudoers(5)> is used.
+
+=item -a I<type>
The B<-a> (I<authentication type>) option causes B<sudo> to use the
specified authentication type when validating the user, as allowed
command in the background. Note that if you use the B<-b>
option you cannot use shell job control to manipulate the process.
-=item -c
+=item -C I<fd>
+
+Normally, B<sudo> will close all open file descriptors other than
+standard input, standard output and standard error. The B<-C>
+(I<close from>) option allows the user to specify a starting point
+above the standard error (file descriptor three). Values less than
+three are not permitted. This option is only available if the
+administrator has enabled the I<closefrom_override> option in
+L<sudoers(5)>.
+
+=item -c I<class>
The B<-c> (I<class>) option causes B<sudo> to run the specified command
with resources limited by the specified login class. The I<class>
-argument can be either a class name as defined in C</etc/login.conf>,
+argument can be either a class name as defined in F</etc/login.conf>,
or a single '-' character. Specifying a I<class> of C<-> indicates
that the command should be run restricted by the default login
capabilities for the user the command is run as. If the I<class>
=item 2.
-The editor specified by the C<VISUAL> or C<EDITOR> environment
-variables is run to edit the temporary files. If neither C<VISUAL>
-nor C<EDITOR> are set, the program listed in the I<editor> I<sudoers>
-variable is used.
+The editor specified by the C<SUDO_EDITOR>, C<VISUAL> or C<EDITOR>
+environment variables is run to edit the temporary files. If none
+of C<SUDO_EDITOR>, C<VISUAL> or C<EDITOR> are set, the first program
+listed in the I<editor> I<sudoers> variable is used.
=item 3.
user will receive a warning and the edited copy will remain in a
temporary file.
+=item -g I<group>
+
+Normally, B<sudo> sets the primary group to the one specified by
+the passwd database for the user the command is being run as (by
+default, root). The B<-g> (I<group>) option causes B<sudo> to run
+the specified command with the primary group set to I<group>. To
+specify a I<gid> instead of a I<group name>, use I<#gid>. When
+running commands as a I<gid>, many shells require that the '#' be
+escaped with a backslash ('\'). If no B<-u> option is specified,
+the command will be run as the invoking user (not root). In either
+case, the primary group will be set to I<group>.
+
=item -H
The B<-H> (I<HOME>) option sets the C<HOME> environment variable
to the homedir of the target user (root by default) as specified
-in passwd(5). By default, B<sudo> does not modify C<HOME>
-(see I<set_home> and I<always_set_home> in L<sudoers(5)>).
+in passwd(5). The default handling of the C<HOME> environment
+variable depends on L<sudoers(5)> settings. By default, B<sudo>
+will set C<HOME> if I<env_reset> or I<always_set_home> are set, or
+if I<set_home> is set and the B<-s> option is specified on the
+command line.
=item -h
The B<-h> (I<help>) option causes B<sudo> to print a usage message and exit.
-=item -i
+=item -i [command]
The B<-i> (I<simulate initial login>) option runs the shell specified
-in the L<passwd(5)> entry of the user that the command is
-being run as. The command name argument given to the shell begins
-with a `C<->' to tell the shell to run as a login shell. B<sudo>
-attempts to change to that user's home directory before running the
-shell. It also initializes the environment, leaving I<TERM>
-unchanged, setting I<HOME>, I<SHELL>, I<USER>, I<LOGNAME>, and
-I<PATH>, and unsetting all other environment variables. Note that
-because the shell to use is determined before the I<sudoers> file
-is parsed, a I<runas_default> setting in I<sudoers> will specify
-the user to run the shell as but will not affect which shell is
-actually run.
+in the L<passwd(5)> entry of the target user as a login shell. This
+means that login-specific resource files such as C<.profile> or
+C<.login> will be read by the shell. If a command is specified,
+it is passed to the shell for execution. Otherwise, an interactive
+shell is executed. B<sudo> attempts to change to that user's home
+directory before running the shell. It also initializes the
+environment, leaving I<DISPLAY> and I<TERM> unchanged, setting
+I<HOME>, I<MAIL>, I<SHELL>, I<USER>, I<LOGNAME>, and I<PATH>, as well as
+the contents of F</etc/environment> on Linux and AIX systems.
+All other environment variables are removed.
=item -K
The B<-K> (sure I<kill>) option is like B<-k> except that it removes
-the user's timestamp entirely. Like B<-k>, this option does not
-require a password.
+the user's time stamp entirely and may not be used in conjunction
+with a command or other option. This option does not require a
+password.
=item -k
-The B<-k> (I<kill>) option to B<sudo> invalidates the user's timestamp
-by setting the time on it to the Epoch. The next time B<sudo> is
-run a password will be required. This option does not require a password
-and was added to allow a user to revoke B<sudo> permissions from a .logout
-file.
+When used by itself, the B<-k> (I<kill>) option to B<sudo> invalidates
+the user's time stamp by setting the time on it to the Epoch. The
+next time B<sudo> is run a password will be required. This option
+does not require a password and was added to allow a user to revoke
+B<sudo> permissions from a .logout file.
+
+When used in conjunction with a command or an option that may require
+a password, the B<-k> option will cause B<sudo> to ignore the user's
+time stamp file. As a result, B<sudo> will prompt for a password
+(if one is required by I<sudoers>) and will not update the user's
+time stamp file.
=item -L
-The B<-L> (I<list> defaults) option will list out the parameters
-that may be set in a I<Defaults> line along with a short description
-for each. This option is useful in conjunction with L<grep(1)>.
+The B<-L> (I<list> defaults) option will list the parameters that
+may be set in a I<Defaults> line along with a short description for
+each. This option will be removed from a future version of B<sudo>.
+
+=item -l[l] [I<command>]
+
+If no I<command> is specified, the B<-l> (I<list>) option will list
+the allowed (and forbidden) commands for the invoking user (or the
+user specified by the B<-U> option) on the current host. If a
+I<command> is specified and is permitted by I<sudoers>, the
+fully-qualified path to the command is displayed along with any
+command line arguments. If I<command> is specified but not allowed,
+B<sudo> will exit with a status value of 1. If the B<-l> option is
+specified with an B<l> argument (i.e. B<-ll>), or if B<-l>
+is specified multiple times, a longer list format is used.
-=item -l
+=item -n
-The B<-l> (I<list>) option will list out the allowed (and
-forbidden) commands for the invoking user on the current host.
+The B<-n> (I<non-interactive>) option prevents B<sudo> from prompting
+the user for a password. If a password is required for the command
+to run, B<sudo> will display an error messages and exit.
=item -P
target user is in. The real and effective group IDs, however, are
still set to match the target user.
-=item -p
+=item -p I<prompt>
The B<-p> (I<prompt>) option allows you to override the default
password prompt and use a custom one. The following percent (`C<%>')
=item C<%H>
-expanded to the local hostname including the domain name
-(on if the machine's hostname is fully qualified or the I<fqdn>
+expanded to the local host name including the domain name
+(on if the machine's host name is fully qualified or the I<fqdn>
I<sudoers> option is set)
=item C<%h>
-expanded to the local hostname without the domain name
+expanded to the local host name without the domain name
+
+=item C<%p>
+
+expanded to the user whose password is being asked for (respects the
+I<rootpw>, I<targetpw> and I<runaspw> flags in I<sudoers>)
=item C<%U>
=back
+The prompt specified by the B<-p> option will override the system
+password prompt on systems that support PAM unless the
+I<passprompt_override> flag is disabled in I<sudoers>.
+
+=item -r I<role>
+
+The B<-r> (I<role>) option causes the new (SELinux) security context to
+have the role specified by I<role>.
+
=item -S
The B<-S> (I<stdin>) option causes B<sudo> to read the password from
-the standard input instead of the terminal device.
+the standard input instead of the terminal device. The password must
+be followed by a newline character.
-=item -s
+=item -s [command]
The B<-s> (I<shell>) option runs the shell specified by the I<SHELL>
-environment variable if it is set or the shell as specified
-in L<passwd(5)>.
+environment variable if it is set or the shell as specified in
+L<passwd(5)>. If a command is specified, it is passed to the shell
+for execution. Otherwise, an interactive shell is executed.
+
+=item -t I<type>
+
+The B<-t> (I<type>) option causes the new (SELinux) security context to
+have the type specified by I<type>. If no type is specified, the default
+type is derived from the specified role.
-=item -u
+=item -U I<user>
+
+The B<-U> (I<other user>) option is used in conjunction with the B<-l>
+option to specify the user whose privileges should be listed. Only
+root or a user with B<sudo> C<ALL> on the current host may use this
+option.
+
+=item -u I<user>
The B<-u> (I<user>) option causes B<sudo> to run the specified
command as a user other than I<root>. To specify a I<uid> instead
-of a I<username>, use I<#uid>. When running commands as a I<uid>,
+of a I<user name>, use I<#uid>. When running commands as a I<uid>,
many shells require that the '#' be escaped with a backslash ('\').
Note that if the I<targetpw> Defaults option is set (see L<sudoers(5)>)
it is not possible to run commands with a uid not listed in the
=item -v
If given the B<-v> (I<validate>) option, B<sudo> will update the
-user's timestamp, prompting for the user's password if necessary.
+user's time stamp, prompting for the user's password if necessary.
This extends the B<sudo> timeout for another C<@timeout@> minutes
(or whatever the timeout is set to in I<sudoers>) but does not run
a command.
=item --
-The B<--> flag indicates that B<sudo> should stop processing command
-line arguments. It is most useful in conjunction with the B<-s> flag.
+The B<--> option indicates that B<sudo> should stop processing command
+line arguments.
=back
=head1 RETURN VALUES
-Upon successful execution of a program, the return value from B<sudo>
-will simply be the return value of the program that was executed.
+Upon successful execution of a program, the exit status from B<sudo>
+will simply be the exit status of the program that was executed.
Otherwise, B<sudo> quits with an exit value of 1 if there is a
configuration/permission problem or if B<sudo> cannot execute the
actual C<PATH> environment variable is I<not> modified and is passed
unchanged to the program that B<sudo> executes.
-B<sudo> will check the ownership of its timestamp directory
+B<sudo> will check the ownership of its time stamp directory
(F<@timedir@> by default) and ignore the directory's contents if
it is not owned by root or if it is writable by a user other than
root. On systems that allow non-root users to give away files via
-L<chown(2)>, if the timestamp directory is located in a directory
+L<chown(2)>, if the time stamp directory is located in a directory
writable by anyone (e.g., F</tmp>), it is possible for a user to
-create the timestamp directory before B<sudo> is run. However,
+create the time stamp directory before B<sudo> is run. However,
because B<sudo> checks the ownership and mode of the directory and
its contents, the only damage that can be done is to "hide" files
-by putting them in the timestamp dir. This is unlikely to happen
-since once the timestamp dir is owned by root and inaccessible by
+by putting them in the time stamp dir. This is unlikely to happen
+since once the time stamp dir is owned by root and inaccessible by
any other user, the user placing files there would be unable to get
them back out. To get around this issue you can use a directory
-that is not world-writable for the timestamps (F</var/adm/sudo> for
+that is not world-writable for the time stamps (F</var/adm/sudo> for
instance) or create F<@timedir@> with the appropriate owner (root)
and permissions (0700) in the system startup files.
-B<sudo> will not honor timestamps set far in the future.
+B<sudo> will not honor time stamps set far in the future.
Timestamps with a date greater than current_time + 2 * C<TIMEOUT>
will be ignored and sudo will log and complain. This is done to
-keep a user from creating his/her own timestamp with a bogus
+keep a user from creating his/her own time stamp with a bogus
date on systems that allow users to give away files.
+On systems where the boot time is available, B<sudo> will also not
+honor time stamps from before the machine booted.
+
+Since time stamp files live in the file system, they can outlive a
+user's login session. As a result, a user may be able to login,
+run a command with B<sudo> after authenticating, logout, login
+again, and run B<sudo> without authenticating so long as the time
+stamp file's modification time is within C<@timeout@> minutes (or
+whatever the timeout is set to in I<sudoers>). When the I<tty_tickets>
+option is enabled in I<sudoers>, the time stamp has per-tty granularity
+but still may outlive the user's session. On Linux systems where
+the devpts filesystem is used, Solaris systems with the devices
+filesystem, as well as other systems that utilize a devfs filesystem
+that monotonically increase the inode number of devices as they are
+created (such as Mac OS X), B<sudo> is able to determine when a
+tty-based time stamp file is stale and will ignore it. Administrators
+should not rely on this feature as it is not universally available.
+
Please note that B<sudo> will normally only log the command it
explicitly runs. If a user runs a command such as C<sudo su> or
C<sudo sh>, subsequent commands run from that shell will I<not> be
=item C<EDITOR>
-Default editor to use in B<-e> (sudoedit) mode if C<VISUAL> is not set
+Default editor to use in B<-e> (sudoedit) mode if neither C<SUDO_EDITOR>
+nor C<VISUAL> is set
+
+=item C<MAIL>
+
+In B<-i> mode or when I<env_reset> is enabled in I<sudoers>, set
+to the mail spool of the target user
=item C<HOME>
-In B<-s> or B<-H> mode (or if sudo was configured with the
---enable-shell-sets-home option), set to homedir of the target user
+Set to the home directory of the target user if B<-i> or B<-H> are
+specified, I<env_reset> or I<always_set_home> are set in I<sudoers>,
+or when the B<-s> option is specified and I<set_home> is set in
+I<sudoers>
=item C<PATH>
Used to determine shell to run with C<-s> option
-=item C<SUDO_PROMPT>
+=item C<SUDO_ASKPASS>
-Used as the default password prompt
+Specifies the path to a helper program used to read the password
+if no terminal is available or if the C<-A> option is specified.
=item C<SUDO_COMMAND>
Set to the command run by sudo
-=item C<SUDO_USER>
+=item C<SUDO_EDITOR>
-Set to the login of the user who invoked sudo
+Default editor to use in B<-e> (sudoedit) mode
-=item C<SUDO_UID>
+=item C<SUDO_GID>
-Set to the uid of the user who invoked sudo
+Set to the group ID of the user who invoked sudo
-=item C<SUDO_GID>
+=item C<SUDO_PROMPT>
-Set to the gid of the user who invoked sudo
+Used as the default password prompt
=item C<SUDO_PS1>
-If set, C<PS1> will be set to its value
+If set, C<PS1> will be set to its value for the program being run
+
+=item C<SUDO_UID>
+
+Set to the user ID of the user who invoked sudo
+
+=item C<SUDO_USER>
+
+Set to the login of the user who invoked sudo
=item C<USER>
=item C<VISUAL>
-Default editor to use in B<-e> (sudoedit) mode
+Default editor to use in B<-e> (sudoedit) mode if C<SUDO_EDITOR>
+is not set
=back
=head1 FILES
-=over 4
+=over 24
+
+=item F<@sysconfdir@/sudoers>
+
+List of who can run what
-=item F<@sysconfdir@/sudoers>C< >List of who can run what
+=item F<@timedir@>
-=item F<@timedir@>C< >Directory containing timestamps
+Directory containing time stamps
+
+=item F</etc/environment>
+
+Initial environment for B<-i> mode on Linux and AIX
=back
$ sudo ls /usr/local/protected
-To list the home directory of user yazza on a machine where the
-file system holding ~yazza is not exported as root:
+To list the home directory of user yaz on a machine where the
+file system holding ~yaz is not exported as root:
- $ sudo -u yazza ls ~yazza
+ $ sudo -u yaz ls ~yaz
To edit the F<index.html> file as user www:
$ sudo -u www vi ~www/htdocs/index.html
+To view system logs only accessible to root and users in the adm group:
+
+ $ sudo -g adm view /var/log/syslog
+
+To run an editor as jim with a different primary group:
+
+ $ sudo -u jim -g audio vi ~jim/sound.txt
+
To shutdown a machine:
$ sudo shutdown -r +15 "quick reboot"
=head1 SEE ALSO
-L<grep(1)>, L<su(1)>, L<stat(2)>, L<login_cap(3)>, L<passwd(5)>,
-L<sudoers(5)>, L<visudo(8)>
+L<grep(1)>, L<su(1)>, L<stat(2)>,
+L<login_cap(3)>,
+L<passwd(5)>, L<sudoers(5)>, L<visudo(8)>
=head1 AUTHORS
version consists of code written primarily by:
Todd C. Miller
- Chris Jepeway
See the HISTORY file in the B<sudo> distribution or visit
http://www.sudo.ws/sudo/history.html for a short history
projects / debian / sudo / blobdiff