dwmblocks-async

A dwm status bar that has a modular, async design, so it is always responsive. Imagine i3blocks, but for dwm.

Features

• Modular
• Lightweight
• Suckless
• Blocks:
  • Clickable
  • Loaded asynchronously
  • Updates can be externally triggered
• Compatible with i3blocks scripts

Additionally, this build of dwmblocks is more optimized and fixes the flickering of the status bar when scrolling.

Why dwmblocks?

In dwm, you have to set the status bar through an infinite loop, like so:

while :; do
    xsetroot -name "$(date)"
    sleep 30
done

This is inefficient when running multiple commands that need to be updated at different frequencies. For example, to display an unread mail count and a clock in the status bar:

while :; do
    xsetroot -name "$(mailCount) $(date)"
    sleep 60
done

Both are executed at the same rate, which is wasteful. Ideally, the mail counter would be updated every thirty minutes, since there's a limit to the number of requests I can make using Gmail's APIs (as a free user).

dwmblocks allows you to divide the status bar into multiple blocks, each of which can be updated at its own interval. This effectively addresses the previous issue, because the commands in a block are only executed once within that time frame.

Why dwmblocks-async?

The magic of dwmblocks-async is in the async part. Since vanilla dwmblocks executes the commands of each block sequentially, it leads to annoying freezes. In cases where one block takes several seconds to execute, like in the mail and date blocks example from above, the delay is clearly visible. Fire up a new instance of dwmblocks and you'll see!

With dwmblocks-async, the computer executes each block asynchronously (simultaneously).

Installation

Clone this repository, modify config.h appropriately, then compile the program:

git clone https://github.com/UtkarshVerma/dwmblocks-async.git
cd dwmblocks-async
vi config.h
sudo make install

Usage

To set dwmblocks-async as your status bar, you need to run it as a background process on startup. One way is to add the following to ~/.xinitrc:

# The binary of `dwmblocks-async` is named `dwmblocks`
dwmblocks &

Modifying the blocks

You can define your status bar blocks in config.h:

#define BLOCKS(X) \
    ...
    X(" ", "wpctl get-volume @DEFAULT_AUDIO_SINK@ | cut -d' ' -f2", 0, 5) \
    X("󰥔 ", "date '+%H:%M:%S'", 1, 1) \
    ...

Each block has the following properties:

Property	Description
Icon	An icon you wish to prepend to your block output.
Command	The command you wish to execute in your block.
Update interval	Time in seconds, after which you want the block to update. If 0, the block will never be updated.
Update signal	Signal to be used for triggering the block. Must be a positive integer. If 0, a signal won't be set up for the block and it will be unclickable.

Apart from defining the blocks, features can be toggled through config.h:

// String used to delimit block outputs in the status.
#define DELIMITER "  "

// Maximum number of Unicode characters that a block can output.
#define MAX_BLOCK_OUTPUT_LENGTH 45

// Control whether blocks are clickable.
#define CLICKABLE_BLOCKS 1

// Control whether a leading delimiter should be prepended to the status.
#define LEADING_DELIMITER 0

// Control whether a trailing delimiter should be appended to the status.
#define TRAILING_DELIMITER 0

Signalling changes

Most status bars constantly rerun all scripts every few seconds. This is an option here, but a superior choice is to give your block a signal through which you can indicate it to update on relevant event, rather than have it rerun idly.

For example, the volume block has the update signal 5 by default. I run kill -39 $(pidof dwmblocks) alongside my volume shortcuts in dwm to only update it when relevant. Just add 34 to your signal number! You could also run pkill -RTMIN+5 dwmblocks, but it's slower.

To refresh all the blocks, run kill -10 $(pidof dwmblocks) or pkill -SIGUSR1 dwmblocks.

All blocks must have different signal numbers!

Clickable blocks

Like i3blocks, this build allows you to build in additional actions into your scripts in response to click events. You can check out my status bar scripts as references for using the $BLOCK_BUTTON variable.

To use this feature, define the CLICKABLE_BLOCKS feature macro in your config.h:

#define CLICKABLE_BLOCKS 1

Apart from that, you need dwm to be patched with statuscmd.

Credits

This work would not have been possible without Luke's build of dwmblocks and Daniel Bylinka's statuscmd patch.