Secure Linux Virtual Consoles with vlock: Install and Use Guide

What is vlock?

vlock is a command‑line utility for Linux that can lock one or more virtual console (VT) sessions. It is useful on headless or multi‑user systems because a user can protect their own console without affecting other users, and it can also lock all consoles and prevent VT switching.

Installation

# yum install vlock        # RHEL / CentOS / Fedora
$ sudo apt-get install vlock   # Ubuntu / Debian / Mint

Command syntax

# vlock [option] [option plugin] [option -t <timeout> plugin]

Common options and usage

Lock the current session (default) # vlock --current Equivalent to running vlock without arguments; it locks the VT from which the command is invoked.

Lock all sessions and disable VT switching # vlock --all All virtual consoles belonging to the user are locked and the Alt+Fx key sequence is disabled.

Switch to a new VT before locking # vlock --new The command creates a fresh virtual console, switches to it, and then locks it. This is handy when you want to leave the original VT untouched.

Disable SysRq while locking all sessions # vlock -sa The -s (or --disable-sysrq ) flag works only together with --all and disables the kernel’s SysRq key combinations during the lock.

Set a screen‑saver timeout # vlock --timeout 5 Specifies the number of seconds after which the built‑in screen‑saver activates while the console is locked.

Use -h or --help to display the help message, and -v or --version to show the program version.

Configuration file

vlock reads a user‑specific configuration file ~/.vlockrc at start‑up. Options placed in this file are applied automatically each time vlock runs. Debian‑based distributions often set additional environment variables that can be added to this file for customized behaviour.

References

Original articles: http://www.tecmint.com/vlock-lock-user-virtual-console-terminal-linux/ ; https://linux.cn/article-7517-1

Illustrative screenshots