runuser(1) — Linux manual page


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 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         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 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

       -, -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

       -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

              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         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 the
       --login command-line option and the PAM system setting (e.g.,

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
       2020-09-18.  (At that time, the date of the most recent commit that
       was found in the repository was 2020-09-15.)  If you discover any
       rendering problems in this HTML version of the page, or you believe
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       (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)