id, /usr/bin/id
Explanation:
The id command will display the user ID (uid), the primary group ID (gid), and the supplementary groups (groups) of a user. The output will show the names and the numerical IDs of the groups.
For example:
id linuxize
The command will show the user ID (uid), the user's primary group (gid), and the user's secondary groups (groups) uid=1001(linuxize) gid=1001(linuxize) groups=1001(linuxize),27(sudo)
To print only the names instead of the numbers use the -n option.
id -nG linuxize
The command will show only the names of the groups
linuxize sudo
The id command is part of the GNU coreutils package and is available on all Linux systems. The full path of the command is /usr/bin/id. References:
* id(1) - Linux manual page
* How to List Groups in Linux | Linuxize

/etc/nologin

The syslog.conf file is the main configuration file for the syslogd daemon, which logs system messages on Linux systems. This file specifies rules for logging, using a selector field and an action field. The selector field consists of a facility and a priority, separated by a period. The facility indicates the subsystem that produced the message, such as mail, auth, or kern. The priority indicates the severity of the message, such as debug, info, or emerg. An asterisk (*) stands for all facilities or all priorities, depending on where it is used. The action field specifies where the message should be logged, such as a file, a user, or a device.
To have all syslog messages generated by the system go to virtual console 12, which is represented by the device file /dev/tty12, the following entry can be added to the syslog.conf file:
. /dev/tty12
This means that any facility and any priority (.) should be logged to the device /dev/tty12. This will redirect all the messages that would normally go to /var/log/messages to the console 12. To see the messages, the user can press Ctrl-Alt-F12 to switch to that console.
Reference:
syslog.conf (5) - Linux man page
Beginner's Guide to Syslogs in Linux [Real World Examples]
Configuration Formats - rsyslog 8.33-20180109-54df0f2 documentation