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.

       Since version 2.38 runuser resets process resource limits

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 (sync
           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 root.

           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.

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

       -V, --version
           Print version 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

       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:

           Generic error before executing the requested command

           The requested command could not be executed

           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)

REPORTING BUGS         top

       For bug reports, use the issue tracker at

AVAILABILITY         top

       The runuser command is part of the util-linux package which can
       be downloaded from Linux Kernel Archive
       <>. 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
       2022-12-17. (At that time, the date of the most recent commit
       that was found in the repository was 2022-12-13.) 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 2.38.643-57df0      2022-12-17                     RUNUSER(1)

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