RUNUSER(1)                      User Commands                     RUNUSER(1)

NAME         top

       runuser - run a command with substitute user and group ID

SYNOPSIS         top

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

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

DESCRIPTION         top

       runuser allows to run commands with a substitute user and group ID.
       If the option -u is not given, it 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 recommended solution is to
       use setpriv(1) command.

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

       For backward compatibility, runuser defaults to not change the
       current directory and to only set 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 final
       environment modification.  The command line options like --login or
       --preserve-environment affect environment before it's modified by

OPTIONS         top

       -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 supplemental 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

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

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

                 o      initializes the environment variables HOME, SHELL,
                        USER, LOGNAME, PATH

                 o      changes to the target user's home directory

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

       -P, --pty
              Create pseudo-terminal for the session. The independent
              terminal provides better security as user does not share
              terminal with the original session.  This allow to avoid
              TIOCSTI ioctl terminal injection and another security attacks
              against terminal file descriptors. The all session is also
              possible to move to background (e.g., "runuser --pty -u
              username -- command &").  If the pseudo-terminal is enabled
              then runuser command 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 pipe
              (e.g., echo "date" | runuser --pty -u user) than ECHO flag for
              the pseudo-terminal is disabled to avoid messy output.

       -m, -p, --preserve-environment
              Preserve the entire environment, i.e., it does not set HOME,
              SHELL, USER nor 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:

                 o      the shell specified with --shell

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

                 o      the shell listed in the passwd entry of the target

                 o      /bin/sh

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

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

       -w, --whitelist-environment=list
              Don't reset environment variables specified in comma separated
              list when clears 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         top

       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:

       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
       --login command line option and PAM system setting (e.g. pam_env).

EXIT STATUS         top

       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         top

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

HISTORY         top

       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         top

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

AVAILABILITY         top

       The runuser command is part of the util-linux package and is
       available from Linux Kernel Archive 

COLOPHON         top

       This page is part of the util-linux (a random collection of Linux
       utilities) project.  Information about the project can be found at 
       ⟨⟩.  If you have a
       bug report for this manual page, send it to  This page was obtained from the
       project's upstream Git repository
       ⟨git://⟩ on
       2020-05-27.  (At that time, the date of the most recent commit that
       was found in the repository was 2020-05-27.)  If you discover any
       rendering problems in this HTML version of the page, or you believe
       there is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to

util-linux                        July 2014                       RUNUSER(1)

Pages that refer to this page: setpriv(1)su(1)credentials(7)