NAME

runuser - run a command with substitute user and group ID

SYNOPSIS

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

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

DESCRIPTION

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

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.

OPTIONS

-c command, --command=command: Pass command to the shell with the -c option.
--session-command=command: Same as -c but do not create a new session (discouraged).
-f, --fast: Pass -f to the shell which may or may not be useful depending on the shell.
-g, --group=group: specify the primary group, this option is allowed for 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 unspecified.
-, -l, --login: Starts the shell as login shell with an environment similar to a real login:

o: clears all environment variables except for TERM
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

-m, -p, --preserve-environment: Preserves the whole environment, ie does not set HOME, SHELL, USER nor LOGNAME. The option is ignored if the option --login is specified.
-s SHELL, --shell=SHELL: Runs 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 user
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.

--help: Display help text and exit.
--version: Display version information 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. 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.

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 could 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

AUTHOR

Derived from coreutils' su which was based on an implemenation from David MacKenzie and Fedora runuser command from Dan Walsh.

AVAILABILITY

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