i3lock is a simple screen locker like slock. After starting it, you will see a white screen (you can configure the color/an image). You can return to your screen by entering your password.

Many little improvements have been made to i3lock over time:

• Fuzzy option added. With that there is no image or solid color displayed when screen is locked. A blurring filter is applied to the screen.

• i3lock forks, so you can combine it with an alias to suspend to RAM (run "i3lock && echo mem > /sys/power/state" to get a locked screen after waking up your computer from suspend to RAM)

• You can specify either a background color or a PNG image which will be displayed while your screen is locked.

• You can specify whether i3lock should bell upon a wrong password.

• i3lock uses PAM and therefore is compatible with LDAP etc. On OpenBSD i3lock uses the bsd_auth(3) framework.

• pkg-config
• libxcb
• libxcb-util
• libpam-dev
• libcairo-dev
• libxcb-xinerama
• libxcb-randr
• libev
• libx11-dev
• libx11-xcb-dev
• libxkbcommon >= 0.5.0
• libxkbcommon-x11 >= 0.5.0
• libGL

Install packages in Ubuntu

sudo apt-get install pkg-config libxcb1-dev libxcb1 libgl2ps-dev libx11-dev libglc0 libglc-dev libcairo2-dev libcairo-gobject2 libcairo2-dev libxkbfile-dev libxkbfile1 libxkbcommon-dev libxkbcommon-x11-dev libxcb-xkb-dev libxcb-dpms0-dev libxcb-damage0-dev libpam0g-dev libev-dev libxcb-image0-dev libxcb-util0-dev libxcb-composite0-dev libxcb-xinerama0-dev

Simply invoke the 'i3lock' command. To get out of it, enter your password and press enter.

To run i3lock with the blurring, please use the --fuzzy option. The amount of blurring can be changed with the --radius and --sigma flags. Please check the man page.

On OpenBSD the i3lock binary needs to be setgid auth to call the authentication helpers, e.g. /usr/libexec/auth/login_passwd.

Please submit general pull requests to https://github.com/i3/i3lock Everything related to blurring mode should be submitted to https://github.com/karulont/i3lock-blur