Provided by: util-linux_2.36.1-8ubuntu1_amd64 bug

NAME

       runuser - run a command with substitute user and group ID

SYNOPSIS

       runuser [options] -u user [[--] command [argument...]]

       runuser [options] [-] [user [argument...]]

DESCRIPTION

       runuser can be used to run commands with a substitute user and group ID.  If the option -u
       is not given, runuser falls back to su-compatible semantics and a shell is executed.   The
       difference between the commands runuser and su is that runuser does not ask for a password
       (because it may be  executed  by  the  root  user  only)  and  it  uses  a  different  PAM
       configuration.   The  command  runuser  does  not  have  to  be installed with set-user-ID
       permissions.

       If the PAM session is not required, then the recommended solution is to use the setpriv(1)
       command.

       When called without arguments, runuser defaults to running an interactive shell as root.

       For  backward compatibility, runuser defaults to not changing the current directory and to
       setting only the environment variables HOME and SHELL (plus USER and LOGNAME if the target
       user is not root).  This version of runuser uses PAM for session management.

       Note  that  runuser  in  all  cases use PAM (pam_getenvlist()) to do the final environment
       modification.  Command-line options such as --login and --preserve-environment affect  the
       environment before it is modified by PAM.

OPTIONS

       -c, --command=command
              Pass command to the shell with the -c option.

       -f, --fast
              Pass -f to the shell, which may or may not be useful, depending on the shell.

       -g, --group=group
              The primary group to be used.  This option is allowed for the root user only.

       -G, --supp-group=group
              Specify  a  supplementary  group.   This option is available to the root user only.
              The first specified supplementary group is also used as  a  primary  group  if  the
              option --group is not specified.

       -, -l, --login
              Start the shell as a login shell with an environment similar to a real login:

              * clears  all  the environment variables except for TERM and variables specified by
                --whitelist-environment

              * initializes the environment variables HOME, SHELL, USER, LOGNAME, and PATH

              * changes to the target user's home directory

              * sets argv[0] of the shell to '-' in order to make the shell a login shell

       -P, --pty
              Create a pseudo-terminal for the session. The independent terminal provides  better
              security as the user does not share a terminal with the original session.  This can
              be used to avoid TIOCSTI  ioctl  terminal  injection  and  other  security  attacks
              against  terminal  file  descriptors.   The entire session can also be moved to the
              background (e.g., "runuser --pty -u  username  --  command  &").   If  the  pseudo-
              terminal is enabled, then runuser works as a proxy between the sessions (copy stdin
              and stdout).

              This feature is mostly designed for interactive sessions.  If the standard input is
              not a terminal, but for example a pipe (e.g., echo "date" | runuser --pty -u user),
              then the ECHO flag for the pseudo-terminal is disabled to avoid messy output.

       -m, -p, --preserve-environment
              Preserve the entire environment, i.e., do not set HOME,  SHELL,  USER  or  LOGNAME.
              The option is ignored if the option --login is specified.

       -s, --shell=shell
              Run  the  specified  shell  instead  of  the default.  The shell to run is selected
              according to the following rules, in order:

              * the shell specified with --shell

              * the   shell   specified   in   the   environment   variable    SHELL    if    the
                --preserve-environment option is used

              * the shell listed in the passwd entry of the target user

              * /bin/sh

              If  the  target user has a restricted shell (i.e., not listed in /etc/shells), then
              the --shell option and the SHELL  environment  variables  are  ignored  unless  the
              calling user is root.

       --session-command=command
              Same as -c, but do not create a new session.  (Discouraged.)

       -w, --whitelist-environment=list
              Don't  reset  the  environment variables specified in the comma-separated list when
              clearing the environment for --login. The whitelist is ignored for the  environment
              variables HOME, SHELL, USER, LOGNAME, and PATH.

       -V, --version
              Display version information and exit.

       -h, --help
              Display help text and exit.

CONFIG FILES

       runuser  reads  the  /etc/default/runuser  and  /etc/login.defs  configuration files.  The
       following configuration items are relevant for runuser:

       ENV_PATH (string)
           Defines the PATH environment variable for  a  regular  user.   The  default  value  is
           /usr/local/bin:/bin:/usr/bin.

       ENV_ROOTPATH (string)
       ENV_SUPATH (string)
           Defines  the  PATH  environment  variable for root.  ENV_SUPATH takes precedence.  The
           default value is /usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin.

       ALWAYS_SET_PATH (boolean)
           If set to yes and  --login  and  --preserve-environment  were  not  specified  runuser
           initializes PATH.

       The  environment variable PATH may be different on systems where /bin and /sbin are merged
       into /usr; this variable is also affected by the --login command-line option and  the  PAM
       system setting (e.g., pam_env(8)).

EXIT STATUS

       runuser  normally  returns the exit status of the command it executed.  If the command was
       killed by a signal, runuser returns the number of the signal plus 128.

       Exit status generated by runuser itself:

                 1      Generic error before executing the requested command

                 126    The requested command could not be executed

                 127    The requested command was not found

FILES

       /etc/pam.d/runuser
                        default PAM configuration file
       /etc/pam.d/runuser-l
                        PAM configuration file if --login is specified
       /etc/default/runuser
                        runuser specific logindef config file
       /etc/login.defs  global logindef config file

HISTORY

       This  runuser command was derived from coreutils' su, which was based on an implementation
       by David MacKenzie, and the Fedora runuser command by Dan Walsh.

SEE ALSO

       setpriv(1), su(1), login.defs(5), shells(5), pam(8)

AVAILABILITY

       The  runuser  command is part of the util-linux package and is available from Linux Kernel
       Archive ⟨https://www.kernel.org/pub/linux/utils/util-linux/⟩.