i3 - improved tiling WM


User-contributed article: Using conky with i3bar

As explained in the i3 documentation, it’s possible to use an external program to build the status information displayed by i3bar. One of those programs is conky, a free, light-weight system monitor.

Since conky does not support the i3bar protocol by default, we could use the plain text output format, but then we cannot have i3bar display colors. This article shows how to configure conky to have colors with i3bar.

As explained in more detail in the i3bar protocol description, i3bar can receive input serialized as JSON, and this way has color support, among other things (urgency flag, shortening description if more space is needed).

Example of colored status with conky

First of all we have to understand how i3bar expects JSON input: We have to provide an "infinite array", each element on that array is a "status line" that is displayed at a certain moment by i3bar.

Let's make a short example. We want to build a very simple status that displays the amunt of free space in home folder and the percentage of used RAM. Here's a sample JSON text for achieving our goal:

{"version":1}
[
 [].

 [ { "full_text":"Home 84.0G Free", "color":"#ffffff" },
   { "full_text":"RAM 32%" , "color":"#ffffff" } ],

 [ { "full_text":"Home 84.0G Free", "color":"#ffffff" },
   { "full_text":"RAM 34%" , "color":"#ffffff" } ],

 [....],
 [....],
 ...

The first line tells i3bar that we are using JSON input. The second line is the opening of the "infinite array". Each line after second is one "instance status" to be displayed in i3bar,

Wrapper script

To obtain this output with conky we have to use it in combination with a short script. The script will write down the "fixed" part of the output (first and second line), then it will call conky. It will be conky’s duty to write each of the "instances".

The script is quite simple:

#!/bin/sh

# Send the header so that i3bar knows we want to use JSON:
echo '{"version":1}'

# Begin the endless array.
echo '['

# We send an empty first array of blocks to make the loop simpler:
echo '[],'

# Now send blocks with information forever:
exec conky -c $HOME/.conkyrc

Let's save this script as conky-i3bar in $HOME/bin. In the i3 config file the bar config will be something like that

bar {
    status_command $HOME/bin/conky-i3bar
}

conky configuration

Now we have to write a ~/.conkyrc file in order to obtain the desired status:

[{ "full_text":"Home 84.0G Free" , "color":"#ffffff" },
 { "full_text":"RAM 32%" , "color":"#ffffff" }],

Here's a sample conkyrc that updates every 2 seconds. Just to make things a litte bit more exciting we put a condition in the script in order to write the occupied RAM in red if the amount is more than 90%:

out_to_x no
own_window no
out_to_console yes
background no
max_text_width 0

# Update interval in seconds
update_interval 2.0

# This is the number of times Conky will update before quitting.
# Set to zero to run forever.
total_run_times 0

# Shortens units to a single character (kiB->k, GiB->G, etc.). Default is off.
short_units yes

# How strict should if_up be when testing an interface for being up?
# The value is one of up, link or address, to check for the interface
# being solely up, being up and having link or being up, having link
# and an assigned IP address. 
if_up_strictness address

# Add spaces to keep things from moving about?  This only affects certain objects.
# use_spacer should have an argument of left, right, or none
use_spacer left

# Force UTF8? note that UTF8 support required XFT
override_utf8_locale no

# number of cpu samples to average
# set to 1 to disable averaging
cpu_avg_samples 2

# Stuff after 'TEXT' will be formatted on screen
TEXT

# JSON for i3bar

 [{ "full_text" : "Home ${fs_free /home} Free" , "color" : "\#ffffff" },
  { "full_text" : "RAM ${memperc}%" , "color" :
    ${if_match ${memperc}<90}"\#ffffff"${else}"\#ff0000"${endif} }],