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 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

              * 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.

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

       -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:

       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         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

                 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
              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
       2021-03-21.  (At that time, the date of the most recent commit
       that was found in the repository was 2021-03-19.)  If you
       discover any rendering problems in this HTML version of the page,
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       manual page), send a mail to

util-linux                      July 2014                     RUNUSER(1)

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