1RUNUSER(1) User Commands RUNUSER(1)
2
6 runuser - run a command with substitute user and group ID
7
9 runuser [options] -u user [[--] command [argument...]]
10 runuser [options] [-] [user [argument...]]
12
14 runuser can be used to run commands with a substitute user and group
15 ID. If the option -u is not given, runuser falls back to su-compatible
16 semantics and a shell is executed. The difference between the commands
17 runuser and su is that runuser does not ask for a password (because it
18 may be executed by the root user only) and it uses a different PAM
19 configuration. The command runuser does not have to be installed with
20 set-user-ID permissions.
21 If the PAM session is not required, then the recommended solution is to
23 use the setpriv(1) command.
24 When called without arguments, runuser defaults to running an
26 interactive shell as root.
27 For backward compatibility, runuser defaults to not changing the
29 current directory and to setting only the environment variables HOME
30 and SHELL (plus USER and LOGNAME if the target user is not root). This
31 version of runuser uses PAM for session management.
32 Note that runuser in all cases use PAM (pam_getenvlist()) to do the
34 final environment modification. Command-line options such as --login
35 and --preserve-environment affect the environment before it is modified
36 by PAM.
37 Since version 2.38 runuser resets process resource limits RLIMIT_NICE,
39 RLIMIT_RTPRIO, RLIMIT_FSIZE, RLIMIT_AS and RLIMIT_NOFILE.
40
42 -c, --command=command
43 Pass command to the shell with the -c option.
44 -f, --fast
46 Pass -f to the shell, which may or may not be useful, depending on
47 the shell.
48 -g, --group=group
50 The primary group to be used. This option is allowed for the root
51 user only.
52 -G, --supp-group=group
54 Specify a supplementary group. This option is available to the root
55 user only. The first specified supplementary group is also used as
56 a primary group if the option --group is not specified.
57 -, -l, --login
59 Start the shell as a login shell with an environment similar to a
60 real login:
61 • clears all the environment variables except for TERM and
63 variables specified by --whitelist-environment
64 • initializes the environment variables HOME, SHELL, USER,
66 LOGNAME, and PATH
67 • changes to the target user’s home directory
69 • sets argv[0] of the shell to '-' in order to make the shell a
71 login shell
72 -P, --pty
74 Create a pseudo-terminal for the session. The independent terminal
75 provides better security as the user does not share a terminal with
76 the original session. This can be used to avoid TIOCSTI ioctl
77 terminal injection and other security attacks against terminal file
78 descriptors. The entire session can also be moved to the background
79 (e.g., runuser --pty -u username -- command &). If the
80 pseudo-terminal is enabled, then runuser works as a proxy between
81 the sessions (sync stdin and stdout).
82 This feature is mostly designed for interactive sessions. If the
84 standard input is not a terminal, but for example a pipe (e.g.,
85 echo "date" | runuser --pty -u user), then the ECHO flag for the
86 pseudo-terminal is disabled to avoid messy output.
87 -m, -p, --preserve-environment
89 Preserve the entire environment, i.e., do not set HOME, SHELL, USER
90 or LOGNAME. The option is ignored if the option --login is
91 specified.
92 -s, --shell=shell
94 Run the specified shell instead of the default. The shell to run is
95 selected according to the following rules, in order:
96 • the shell specified with --shell
98 • the shell specified in the environment variable SHELL if the
100 --preserve-environment option is used
101 • the shell listed in the passwd entry of the target user
103 • /bin/sh
105 If the target user has a restricted shell (i.e., not listed in
107 /etc/shells), then the --shell option and the SHELL environment
108 variables are ignored unless the calling user is root.
109 --session-command=command
111 Same as -c, but do not create a new session. (Discouraged.)
112 -w, --whitelist-environment=list
114 Don’t reset the environment variables specified in the
115 comma-separated list when clearing the environment for --login. The
116 whitelist is ignored for the environment variables HOME, SHELL,
117 USER, LOGNAME, and PATH.
118 -h, --help
120 Display help text and exit.
121 -V, --version
123 Print version and exit.
124
126 runuser reads the /etc/default/runuser and /etc/login.defs
127 configuration files. The following configuration items are relevant for
128 runuser:
129 ENV_PATH (string)
131 Defines the PATH environment variable for a regular user. The
132 default value is /usr/local/bin:/bin:/usr/bin.
133 ENV_ROOTPATH (string), ENV_SUPATH (string)
135 Defines the PATH environment variable for root. ENV_SUPATH takes
136 precedence. The default value is
137 /usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin.
138 ALWAYS_SET_PATH (boolean)
140 If set to yes and --login and --preserve-environment were not
141 specified runuser initializes PATH.
142 The environment variable PATH may be different on systems where /bin
144 and /sbin are merged into /usr; this variable is also affected by the
145 --login command-line option and the PAM system setting (e.g.,
146 pam_env(8)).
147
149 runuser normally returns the exit status of the command it executed. If
150 the command was killed by a signal, runuser returns the number of the
151 signal plus 128.
152 Exit status generated by runuser itself:
154 1
156 Generic error before executing the requested command
157 126
159 The requested command could not be executed
160 127
162 The requested command was not found
163
165 /etc/pam.d/runuser
166 default PAM configuration file
167 /etc/pam.d/runuser-l
169 PAM configuration file if --login is specified
170 /etc/default/runuser
172 runuser specific logindef config file
173 /etc/login.defs
175 global logindef config file
176
178 This runuser command was derived from coreutils' su, which was based on
179 an implementation by David MacKenzie, and the Fedora runuser command by
180 Dan Walsh.
181
183 setpriv(1), su(1), login.defs(5), shells(5), pam(8)
184
186 For bug reports, use the issue tracker at
187 https://github.com/util-linux/util-linux/issues.
188
190 The runuser command is part of the util-linux package which can be
191 downloaded from Linux Kernel Archive
192 <https://www.kernel.org/pub/linux/utils/util-linux/>.
193util-linux 2.38.1 2022-05-11 RUNUSER(1)