-=cut
-Copyright (c) 1994-1996,1998-2003 Todd C. Miller <Todd.Miller@courtesan.com>
+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
purpose with or without fee is hereby granted, provided that the above
Agency (DARPA) and Air Force Research Laboratory, Air Force
Materiel Command, USAF, under agreement number F39502-99-1-0512.
-$Sudo: sudo.pod,v 1.73 2004/09/08 18:34:38 millert Exp $
=pod
=head1 NAME
=head1 SYNOPSIS
-B<sudo> B<-K> | B<-L> | B<-V> | B<-h> | B<-k> | B<-l> | B<-v>
-
-B<sudo> [B<-HPSb>] 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<-e> file [...] | B<-i> | B<-s> | I<command>}>
-
-B<sudoedit> [B<-S>] S<[B<-a> I<auth_type>]>
-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 -H
+=item -A
-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(@mansectform@). By default, B<sudo> does not modify C<HOME>
-(see I<set_home> and I<always_set_home> in L<sudoers(@mansectform@)>).
-
-=item -K
+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.
-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.
-
-=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 grep(1).
-
-=item -P
-
-The B<-P> (I<preserve group vector>) option causes B<sudo> to
-preserve the invoking user's group vector unaltered. By default,
-B<sudo> will initialize the group vector to the list of groups the
-target user is in. The real and effective group IDs, however, are
-still set to match the target user.
-
-=item -S
-
-The B<-S> (I<stdin>) option causes B<sudo> to read the password from
-the standard input instead of the terminal device.
-
-=item -V
-
-The B<-V> (I<version>) option causes B<sudo> to print the version
-number and exit. If the invoking user is already root the B<-V>
-option will print out a list of the defaults B<sudo> was compiled
-with as well as the machine's local network addresses.
-
-=item -a
+=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
-by /etc/login.conf. The system administrator may specify a list
+by F</etc/login.conf>. The system administrator may specify a list
of sudo-specific authentication methods by adding an "auth-sudo"
-entry in /etc/login.conf. This option is only available on systems
-that support BSD authentication where B<sudo> has been configured
-with the --with-bsdauth option.
+entry in F</etc/login.conf>. This option is only available on systems
+that support BSD authentication.
=item -b
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 /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>
argument specifies an existing user class, the command must be run
as root, or the B<sudo> command must be run from a shell that is already
-root. This option is only available on systems with BSD login classes
-where B<sudo> has been configured with the --with-logincap option.
+root. This option is only available on systems with BSD login classes.
+
+=item -E
+
+The B<-E> (I<preserve> I<environment>) option will override the
+I<env_reset> option in L<sudoers(5)>). It is only
+available when either the matching command has the C<SETENV> tag
+or the I<setenv> option is set in L<sudoers(5)>.
=item -e
the I<sudoers> file. If the user is authorized by I<sudoers>
the following steps are taken:
-=over 8
+=over 4
=item 1.
=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). 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(@mansectform@)> 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 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 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 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
+
+The B<-P> (I<preserve> I<group vector>) option causes B<sudo> to
+preserve the invoking user's group vector unaltered. By default,
+B<sudo> will initialize the group vector to the list of groups the
+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<%>')
escapes are supported:
-=over 8
+=over 4
-=item C<%u>
+=item C<%H>
-expanded to the invoking user's login name
+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 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>
expanded to the login name of the user the command will
be run as (defaults to root)
-=item C<%h>
-
-expanded to the local hostname without the domain name
-
-=item C<%H>
+=item C<%u>
-expanded to the local hostname including the domain name
-(on if the machine's hostname is fully qualified or the I<fqdn>
-sudoers option is set)
+expanded to the invoking user's login name
=item C<%%>
=back
-=item -s
+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 password must
+be followed by a newline character.
+
+=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(@mansectform@)>.
+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 I<user>
-=item -u
+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<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
+password database.
+
+=item -V
-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>. Note that if the I<targetpw> Defaults
-option is set (see L<sudoers(@mansectform@)>) it is not possible
-to run commands with a uid not listed in the password database.
+The B<-V> (I<version>) option causes B<sudo> to print the version
+number and exit. If the invoking user is already root the B<-V>
+option will print out a list of the defaults B<sudo> was compiled
+with as well as the machine's local network addresses.
=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
+Environment variables to be set for the command may also be passed
+on the command line in the form of B<VAR>=I<value>, e.g.
+B<LD_LIBRARY_PATH>=I</usr/local/pkg/lib>. Variables passed on the
+command line are subject to the same restrictions as normal environment
+variables with one important exception. If the I<setenv> option
+is set in I<sudoers>, the command to be run has the C<SETENV> tag
+set or the command matched is C<ALL>, the user may set variables
+that would overwise be forbidden. See L<sudoers(5)> for more information.
+
=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
=head1 SECURITY NOTES
-B<sudo> tries to be safe when executing external commands. Variables
-that control how dynamic loading and binding is done can be used
-to subvert the program that B<sudo> runs. To combat this the
-C<LD_*>, C<_RLD_*>, C<SHLIB_PATH> (HP-UX only), and C<LIBPATH> (AIX
-only) environment variables are removed from the environment passed
-on to all commands executed. B<sudo> will also remove the C<IFS>,
-C<CDPATH>, C<ENV>, C<BASH_ENV>, C<KRB_CONF>, C<KRBCONFDIR>, C<KRBTKFILE>,
-C<KRB5_CONFIG>, C<LOCALDOMAIN>, C<RES_OPTIONS>, C<HOSTALIASES>,
-C<NLSPATH>, C<PATH_LOCALE>, C<TERMINFO>, C<TERMINFO_DIRS> and
-C<TERMPATH> variables as they too can pose a threat. If the
-C<TERMCAP> variable is set and is a pathname, it too is ignored.
-Additionally, if the C<LC_*> or C<LANGUAGE> variables contain the
-C</> or C<%> characters, they are ignored. Environment variables
-with a value beginning with C<()> are also removed as they could
-be interpreted as B<bash> functions. If B<sudo> has been
-compiled with SecurID support, the C<VAR_ACE>, C<USR_ACE> and
-C<DLC_ACE> variables are cleared as well. The list of environment
-variables that B<sudo> clears is contained in the output of
-C<sudo -V> when run as root.
+B<sudo> tries to be safe when executing external commands.
+
+There are two distinct ways to deal with environment variables.
+By default, the I<env_reset> I<sudoers> option is enabled.
+This causes commands to be executed with a minimal environment
+containing C<TERM>, C<PATH>, C<HOME>, C<SHELL>, C<LOGNAME>, C<USER>
+and C<USERNAME> in addition to variables from the invoking process
+permitted by the I<env_check> and I<env_keep> I<sudoers> options.
+There is effectively a whitelist for environment variables.
+
+If, however, the I<env_reset> option is disabled in I<sudoers>, any
+variables not explicitly denied by the I<env_check> and I<env_delete>
+options are inherited from the invoking process. In this case,
+I<env_check> and I<env_delete> behave like a blacklist. Since it
+is not possible to blacklist all potentially dangerous environment
+variables, use of the default I<env_reset> behavior is encouraged.
+
+In all cases, environment variables with a value beginning with
+C<()> are removed as they could be interpreted as B<bash> functions.
+The list of environment variables that B<sudo> allows or denies is
+contained in the output of C<sudo -V> when run as root.
+
+Note that the dynamic linker on most operating systems will remove
+variables that can control dynamic linking from the environment of
+setuid executables, including B<sudo>. Depending on the operating
+system this may include C<_RLD*>, C<DYLD_*>, C<LD_*>, C<LDR_*>,
+C<LIBPATH>, C<SHLIB_PATH>, and others. These type of variables are
+removed from the environment before B<sudo> even begins execution
+and, as such, it is not possible for B<sudo> to preserve them.
To prevent command spoofing, B<sudo> checks "." and "" (both denoting
current directory) last when searching for a command in the user's
actual C<PATH> environment variable is I<not> modified and is passed
unchanged to the program that B<sudo> executes.
-For security reasons, if your OS supports shared libraries and does
-not disable user-defined library search paths for setuid programs
-(most do), you should either use a linker option that disables this
-behavior or link B<sudo> statically.
-
-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 and only writable by 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 writable by anyone (e.g.: F</tmp>),
-it is possible for a user to create the timestamp 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 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 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.
+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 time stamp directory is located in a directory
+writable by anyone (e.g., F</tmp>), it is possible for a user to
+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 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 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 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.
-Please note that B<sudo> will 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 logged, nor
-will B<sudo>'s access control affect them. The same is true for
-commands that offer shell escapes (including most editors). Because
-of this, care must be taken when giving users access to commands
-via B<sudo> to verify that the command does not inadvertently give
-the user an effective root shell.
+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
+logged, nor will B<sudo>'s access control affect them. The same
+is true for commands that offer shell escapes (including most
+editors). Because of this, care must be taken when giving users
+access to commands via B<sudo> to verify that the command does not
+inadvertently give the user an effective root shell. For more
+information, please see the C<PREVENTING SHELL ESCAPES> section in
+L<sudoers(5)>.
=head1 ENVIRONMENT
B<sudo> utilizes the following environment variables:
- EDITOR Default editor to use in -e (sudoedit) mode if
- VISUAL is not set
+=over 16
+
+=item C<EDITOR>
+
+Default editor to use in B<-e> (sudoedit) mode if neither C<SUDO_EDITOR>
+nor C<VISUAL> is set
- HOME In -s or -H mode (or if sudo was configured with
- the --enable-shell-sets-home option), set to
- homedir of the target user
+=item C<MAIL>
- PATH Set to a sane value if sudo was configured with
- the --with-secure-path option
+In B<-i> mode or when I<env_reset> is enabled in I<sudoers>, set
+to the mail spool of the target user
- SHELL Used to determine shell to run with -s option
+=item C<HOME>
- SUDO_PROMPT Used as the default password prompt
+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>
- SUDO_COMMAND Set to the command run by sudo
+=item C<PATH>
- SUDO_USER Set to the login of the user who invoked sudo
+Set to a sane value if the I<secure_path> sudoers option is set.
- SUDO_UID Set to the uid of the user who invoked sudo
+=item C<SHELL>
- SUDO_GID Set to the gid of the user who invoked sudo
+Used to determine shell to run with C<-s> option
- SUDO_PS1 If set, PS1 will be set to its value
+=item C<SUDO_ASKPASS>
- USER Set to the target user (root unless the -u option
- is specified)
+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.
- VISUAL Default editor to use in -e (sudoedit) mode
+=item C<SUDO_COMMAND>
+
+Set to the command run by sudo
+
+=item C<SUDO_EDITOR>
+
+Default editor to use in B<-e> (sudoedit) mode
+
+=item C<SUDO_GID>
+
+Set to the group ID of the user who invoked sudo
+
+=item C<SUDO_PROMPT>
+
+Used as the default password prompt
+
+=item C<SUDO_PS1>
+
+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>
+
+Set to the target user (root unless the B<-u> option is specified)
+
+=item C<VISUAL>
+
+Default editor to use in B<-e> (sudoedit) mode if C<SUDO_EDITOR>
+is not set
+
+=back
=head1 FILES
- @sysconfdir@/sudoers List of who can run what
- @timedir@ Directory containing timestamps
+=over 24
+
+=item F<@sysconfdir@/sudoers>
+
+List of who can run what
+
+=item F<@timedir@>
+
+Directory containing time stamps
+
+=item F</etc/environment>
+
+Initial environment for B<-i> mode on Linux and AIX
+
+=back
=head1 EXAMPLES
-Note: the following examples assume suitable L<sudoers(@mansectform@)> entries.
+Note: the following examples assume suitable L<sudoers(5)> entries.
To get a file listing of an unreadable directory:
$ 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<sudoers(@mansectform@)>,
-L<passwd(@mansectform@)>, L<visudo(@mansectsu@)>
+L<grep(1)>, L<su(1)>, L<stat(2)>,
+L<login_cap(3)>,
+L<passwd(5)>, L<sudoers(5)>, L<visudo(8)>
=head1 AUTHORS
Many people have worked on B<sudo> over the years; this
version consists of code written primarily by:
- Todd Miller
- Chris Jepeway
+ Todd C. Miller
See the HISTORY file in the B<sudo> distribution or visit
http://www.sudo.ws/sudo/history.html for a short history
Also, many programs (such as editors) allow the user to run commands
via shell escapes, thus avoiding B<sudo>'s checks. However, on
most systems it is possible to prevent shell escapes with B<sudo>'s
-I<noexec> functionality. See the L<sudoers(@mansectform@)> manual
+I<noexec> functionality. See the L<sudoers(5)> manual
for details.
-It is not meaningful to run the C<cd> command directly via sudo, e.g.
+It is not meaningful to run the C<cd> command directly via sudo, e.g.,
$ sudo cd /usr/local/protected
-since when whe command exits the parent process (your shell) will
+since when the command exits the parent process (your shell) will
still be the same. Please see the EXAMPLES section for more information.
If users have sudo C<ALL> there is nothing to prevent them from
=head1 SUPPORT
-Commercial support is available for B<sudo>, 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.
=head1 DISCLAIMER
-B<Sudo> is provided ``AS IS'' and any express or implied warranties,
+B<sudo> 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 B<sudo> or http://www.sudo.ws/sudo/license.html
projects / debian / sudo / blobdiff