SimplyLock allows you restrict physical access to your Linux box by locking all virtual terminals.

To lock your computer just call:

simplylock

And you're done. Unlock your computer by pressing Enter and then typing your password.

Note that SimplyLock uses PAM for authentication, it makes no assumptions on the existence of passwords or any other authentication mechanism. To customize SimplyLock behaviour, edit /etc/pam.d/simplylock (or the equivalent for your distribution).

The root user can always unlock.

But he isn't the only one. You can specify a list of users allowed to unlock using the -u option, or if you called SimplyLock without the -u option, you (the caller) will be able to unlock.

If more than one user is allowed to unlock, you can press Ctrl+C before authentication to select from the list of allowed users.

If you use systemd, adding a new unit is enough:

[Unit]
Description=Lock with SimplyLock
Before=sleep.target

[Service]
Type=forking
ExecStart=/bin/simplylock

[Install]
WantedBy=sleep.target

Save this unit to /etc/systemd/system/simplylock.service and issue a systemctl daemon-reload to make sure that the changes are reloaded. Enable the unit with systemctl enable simplylock.

Now, every time you suspend through systemctl suspend, when you resume, your pc will be locked.

Note that if you use this exact unit, only root will be able to unlock at resume. Use the -u option to list other users that can unlock.

If you use Arch Linux, SimplyLock is easily available from the AUR:

$ yaourt -S simplylock-git

If you don't use Arch, you can always compile SimplyLock from source.

To compile SimplyLock from source, you will need PAM and MagickWand headers, so install the package for your distribution. If you use Debian, for example, you can install the following packages:

# apt-get install libpam0g-dev libmagickwand-dev

For Arch Linux:

# pacman -S pam imagemagick

Now, compile and install SimplyLock with the following commands:

$ make
# make install

Note that make install will place the binary in the /usr/bin directory, and will give it root ownership and set the setuid bit, so that everyone can use SimplyLock.

Optionally, you can add a background image to your lock screen. To do so, pass the path to the image to the -b / --background option:

simplylock -b /home/user/Pictures/lock.jpg

By default, the image is resized and centered to the screen. To change this behaviour, use the --background-fill option.

This feature requires the Linux framebuffer: if /dev/fb0 is not available, use the --fbdev option to point to the correct framebuffer device.

Note: this is still preliminary support. Expect glitches and bugs.

Usage: simplylock [-slkdqhv] [-u users] [-m message] [-b path]

-s, --no-sysreq              Keep sysrequests enabled.
-l, --no-lock                Do not lock terminal switching.
-k, --no-kernel-messages     Do not mute kernel messages while the console is locked.
-u, --users users            Comma separated list of users allowed to unlock.
                             Note that the root user will always be able to unlock.
-m, --message message        Display the given message instead of the default one.
-d, --dark                   Dark mode: switch off the screen after locking.
-q, --quick                  Quick mode: do not wait for enter to be pressed to unlock.

-b, --background             Set background image.
    --background-fill        Background fill mode. Available values:
                             - center: center the image without resizing it.
                             - stretch: stretch the image to fill all the available space.
                             - resize: like stretch, but keeps image proportions. (default)
    --fbdev                  Path to the framebuffer device to use to draw the background.

-h, --help                   Display this help text.
-v, --version                Display version information.

See LICENSE file in the root directory.