j3blocks

It is a janet scripting system for i3bar and swaybar. It is distributed as a jpm library. You have to write a janet script to use this library.

Janet is a system scripting language.

Development Status

It doesn't get updates often because this software is finished. I have used it for more than a year without a major issue.

Built-in j3blocks module screenshots

bandwidth

cpu

memory usage

swap usage

time

Extra j3blocks modules

j3blocks tries not to have a lot of built-in modules.

Extra community modules can be found on j3blocks-extra.

You can contribute j3blocks modules to j3blocks-extra.

Basic usage

Built-in j3blocks modules are available in j3blocks/modules.

For example, if you want to use the built-in cpu module, run this janet script as the status command of i3bar or swaybar.

(import j3blocks)
(import j3blocks/modules/cpu)
(import j3blocks/loglevel)

(j3blocks/run
  :unix-socket-name "test"
  :loglevel loglevel/info
  :blocks
  [{:id "cpu"
    :module (cpu/usage)
    :click-event
    (fn
      [input output log]
      (forever
        (case (get (ev/take input) "button")
          # left click
          1
          (ev/give output "update")
          # right click
          3
          (ev/spawn (os/execute ["do" "something"] :p)))))
    :modify-block
    (fn
      [input output log]
      (forever
        (def block (ev/take input))
        (put block "separator" false)
        (put block "markup" "pango")
        (ev/give output block)))}])

The above example disables separator and sets markup to pango in cpu module. Log level is set to info. It also processes click events.

It creates a unix domain socket at $XDG_RUNTIME_DIR/j3blocks/test or /tmp/j3blocks/$UID/test. The unix domain socket messages become block events.

For details, read (doc j3blocks/run).

Unix domain socket

If you want to pass messages to j3blocks unix domain socket, then you should use j3blocks/msg as below.

(import j3blocks/msg)

(msg/send "test" ["static-block1" "instance1"] {"message" "ok"})

In the above example, msg/send sends {"message" "ok"} to a block identified by ["static-block1" "instance1"]. The block is running on a j3blocks instance listening on the unix domain socket, test. Any message sent to a j3blocks block must be valid JSON which can be a string, a number, an object, and so on.

Refer to (doc msg/send) for details.

Every j3blocks block can receive click events and unix domain socket events.

Useful janet modules for j3blocks

• If you want to produce pango markup text, j3blocks/pango module will be useful.
• If your j3blocks module needs to parse /proc/meminfo, j3blocks/procmeminfo module will be useful.
• If your j3blocks module needs to parse /proc/net/dev, j3blocks/procnetdev module will be useful.
• spork/sh is useful for launching programs in response to click events.

Contribution

This library tries not to exceed 120 characters per line.