sudo, sudoedit

execute a command as another user

Execute a command as the superuser or another user,
The real and effective uid and gid are set to match those of the target user.

As usual, this document is a tersified version of the man page, different systems have different versions, check man sudo for exact operations

Frequently used by admins to perform an administrative function and logs commands via syslog notice similar to:

         sudo[9115]:  uunnamme : TTY=ttys000 ; PWD=/private/var/log ; USER=root ; COMMAND=/bin/kill -hup 51

Redirections are started before user ID is changed.

This means that:
/etc > sudo ls -l > listOfiles
will fail.

instead use:
/etc > sudo ls -l > ~/listOfiles

 # Path to askpass helper program
          Path askpass /usr/X11R6/bin/ssh-askpass

 mac os 10.13 :
Sudo version 1.8.17p1
Sudoers policy plugin version 1.8.17p1
Sudoers file grammar version 45
Sudoers I/O plugin version 1.8.17p1

PLUGINS

 
        # Default /etc/sudo.conf file
        #
        # Format:
        #   Plugin plugin_name plugin_path plugin_options ...
        #   Path askpass /path/to/askpass
        #   Path noexec /path/to/sudo_noexec.so
        #   Debug sudo /var/log/sudo_debug all@warn
        #   Set disable_coredump true
        #
        # The plugin_path is relative to /usr/libexec unless
        #   fully qualified.
        # The plugin_name corresponds to a global symbol in the plugin
        #   that contains the plugin interface structure.
        # The plugin_options are optional.
        #
        Plugin policy_plugin sudoers.so
        Plugin io_plugin sudoers.so

PATHS

Path noexec /usr/lib/sudo/sudo_noexec.so Path askpass /usr/X11R6/bin/ssh-askpass

DEBUG FLAGS

A Debug line consists of the Debug keyword, followed by the name of the program to debug (sudo, visudo, sudoreplay), the debug file name and a comma-separated list of debug flags. The debug flag syntax used by sudo and the sudoers plugin is subsystem@priority but the plugin is free to use a different format so long as it does not include a command ,. For instance:

Debug sudo /var/log/sudo_debug all@warn,plugin@info

Currently, only one Debug entry per program is supported. The sudo Debug entry is shared by the sudo front end, sudoedit and the plugins. A future release may add support for per-plugin Debug lines and/or support for multiple debugging files for a single program.

The priorities used by the sudo front end, in order of decreasing severity, are: crit, err, warn, notice, diag, info, trace and debug. Each priority, when specified, also includes all priorities higher than it. For example, a priority of notice would include debug messages logged at notice and higher. The following subsystems are used by sudo:

RETURN VALUES

Otherwise, sudo exits with a value of 1 if there is a configuration/permission problem or if sudo cannot execute the given command. In the latter case the error string is printed to the standard error. If sudo cannot stat(2) one or more entries in the user's PATH, an error is printed on stderr. (If the directory does not exist or if it is not really a directory, the entry is ignored and no error is printed.) This should not happen under normal circumstances. The most common reason for stat(2) to return "permission denied" is if you are running an automounter and one of the directories in your PATH is on a machine that is currently unreachable.

SECURITY NOTES

To prevent command spoofing, sudo checks "." and "" (both denoting current directory) last when searching for a command in the user's PATH (if one or both are in the PATH). Note, however, that the actual PATH environment variable is not modified and is passed unchanged to the program that sudo executes.

Please note that sudo will normally only log the command it explicitly runs. If a user runs a command such as sudo su or sudo sh, subsequent commands run from that shell are not subject to sudo's security policy. The same is true for commands that offer shell escapes (including most editors). If I/O logging is enabled, subsequent commands will have their input and/or output logged, but there will not be traditional logs for those commands. Because of this, care must be taken when giving users access to commands via sudo to verify that the command does not inadvertently give the user an effective root shell. For more information, please see the PREVENTING SHELL ESCAPES section in sudoers(5).

To prevent the disclosure of potentially sensitive information, sudo disables core dumps by default while it is executing (they are re-enabled for the command that is run). To aid in debugging sudo crashes, you may wish to re-enable core dumps by setting "disable_coredump" to false in the /etc/sudo.conf file.

Set disable_coredump false

ENVIRONMENT

FILES

EXAMPLES

$ sudo ls /usr/local/protected

$ sudo -u yaz ls ~yaz

$ sudo -u www vi ~www/htdocs/index.html

$ sudo -g adm view /var/log/syslog

$ sudo -u jim -g audio vi ~jim/sound.txt

$ sudo shutdown -r +15 "quick reboot"

$ sudo sh -c "cd /home ; du -s * | sort -rn > USAGE"

SEE ALSO

CAVEATS

It is not meaningful to run cd directly via sudo, e.g.,

$ sudo cd /usr/local/protected

Running shell scripts via sudo can expose the same kernel bugs that make setuid shell scripts unsafe on some operating systems (if your OS has a /dev/fd/ directory, setuid shell scripts are generally safe).

BUGS

SUPPORT

1.8.5 March 15, 2012

from smackerpro 5/8/13

# This file MUST be edited with the 'visudo' command as root.
# Otherwise syntax or file permission errors may prevent sudo from running.

# Host alias specification

# User alias specification

# Cmnd alias specification

# Defaults specification
Defaults    env_reset
Defaults    env_keep += "BLOCKSIZE"
Defaults    env_keep += "COLORFGBG COLORTERM"
Defaults    env_keep += "__CF_USER_TEXT_ENCODING"
Defaults    env_keep += "CHARSET LANG LANGUAGE LC_ALL LC_COLLATE LC_CTYPE"
Defaults    env_keep += "LC_MESSAGES LC_MONETARY LC_NUMERIC LC_TIME"
Defaults    env_keep += "LINES COLUMNS"
Defaults    env_keep += "LSCOLORS"
Defaults    env_keep += "SSH_AUTH_SOCK"
Defaults    env_keep += "TZ"
Defaults    env_keep += "DISPLAY XAUTHORIZATION XAUTHORITY"
Defaults    env_keep += "EDITOR VISUAL"
Defaults    env_keep += "HOME MAIL"

# Runas alias specification

# User privilege specification
root    ALL=(ALL) ALL
%admin  ALL=(ALL) ALL

# Uncomment to allow people in group wheel to run all commands
# %wheel    ALL=(ALL) ALL

# Same thing without a password
# %wheel    ALL=(ALL) NOPASSWD: ALL

# Samples
# %users  ALL=/sbin/mount /cdrom,/sbin/umount /cdrom
# %users  localhost=/sbin/shutdown -h now

As of 5/8/13 this is taken from man of March 15, 2012 on a system with Sudo version1.8.5p2

See

See Sudo.ws for 1.8.6p8, released on April 11, 2013.