The hacker-friendly status_command for Sway and i3
i3blocks is a feed generator for text based status bars. It executes your command lines and generates a status line from their output. Commands are scheduled at configured time intervals, upon signal reception or on clicks.
The generated line is meant to be displayed by the i3 window manager through its i3bar component, as an alternative to i3status. This program naturally works out of the box with the sway Wayland compositor since it is a drop-in replacement for i3.
i3blocks is meant to be highly flexible but intuitive. No library package is required, just output what your status bar expects, from your favorite programming language and your preferred format.
[click]
full_text=Click me!
command=echo "Got clicked with button $button"
color=#F79494
# Guess the weather hourly
[weather]
command=curl -Ss 'https://wttr.in?0&T&Q' | cut -c 16- | head -2 | xargs echo
interval=3600
color=#A4C2F4
# Query my default IP address only on startup
[ip]
command=hostname -i | awk '{ print "IP:" $1 }'
interval=once
color=#91E78B
# Update time every 5 seconds
[time]
command=date +%T
interval=5i3blocks is already packaged for:
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Archlinux: i3blocks in the community repository and i3blocks-git in the AUR
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Gentoo: x11-misc/i3blocks
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Debian: i3blocks
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Ubuntu: i3blocks
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Fedora (COPR): i3blocks
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Void Linux: i3blocks
Or can be installed from source with:
git clone https://github.com/vivien/i3blocks
cd i3blocks
./autogen.sh
./configure
make
make installSince ticker feature has been introduced, there is only one package (libutf8proc) which is need to be installed. On Debian-based systems it can be obtained via apt:
sudo apt-get install libutf8proc-devIn your i3 configuration file, define i3blocks as the status line command of a new bar block:
bar {
status_command i3blocks
}|
Important
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The project’s repository does not include default scripts anymore. |
For the lazy, you can start from our collection of scripts:
git clone https://github.com/vivien/i3blocks-contrib ~/.config/i3blocks
cd !$
cp config.example configFor the picky, you can start a configuration file in one of the following preferred paths:
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$XDG_CONFIG_HOME/i3blocks/config(or~/.config/i3blocks/config); -
~/.i3blocks.conf; -
$XDG_CONFIG_DIRS/i3blocks/config(or/etc/xdg/i3blocks/config); -
/etc/i3blocks.conf; -
or any other path that you will specify using the
-coption.
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Note
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By default /etc is prefixed by /usr/local when you installed from source.
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Use the example above or dig in the configuration details below.
Now restart i3 with i3-msg restart to apply your changes.
The configuration file uses a simplified INI file format:
# Properties not preceded by a section are considered global
# and merged into every section declarations.
foo=bar
[block1]
baz=qux
# This is a comment
[block2]
quux= quuzIn this example, block2 contains a foo property equal to "bar" and a quux property equal to " quuz" (including the leading space). Everything after the equal sign will be part of the value, thus inline comments won’t be stripped out.
At runtime, these properties are simply variables, that are passed along to the status bar program when printing is necessary. However on startup, i3blocks checks some optional properties to eventually setup the scheduling of a command.
If a block specifies a command, then all of its properties are passed as environment variables at execution, which means that the foo=bar property will be available from a shell script with $foo.
The output of the command is used to update the values of these variables.
The values are reset to default (as defined in the configuration file) before the update, so that blocks get a consistent behavior at each execution.
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Note
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Each line from a block output must be terminated with a newline. |
In order to use i3blocks with i3, its status bar command i3bar expects specific keys. To know how to customize the blocks of your status line, you must refer to the i3bar protocol.
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Note
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full_text is the only mandatory key, the block will be skipped if this key is absent or empty. |
Unless overriden, the section name of the block defines the name key.
Below are examples of static blocks interacting with i3bar.
[simple]
full_text=This is a looong white on red text
short_text=Short white on red text
background=#FF0000
color=#FFFFFF
# Block with a fixed width
[aligned]
full_text=Here.
min_width=100
align=center
# Fancy text with multiple colors and shapes
[funky]
full_text=<span foreground="red" size="x-large">Roses</span> and <i><span color="#EE37B8">violets</span></i>!
markup=pangoThese are some special properties checked by i3blocks on startup. These will be considered as simple variables at runtime.
The optional command property specifies a command line to be executed with sh -c.
The command can be relative to the configuration file where it is defined.
If the command outputs some text, it is used to update the block.
An exit code of 0 means success. A special exit code of 33 will set the urgent i3bar key to true. Any other exit code will raise an error.
[pacman]
full_text=c ·
command=echo "· ${full_text~~}"
color=#FFFF00The optional interval property specifies when the command must be scheduled.
A positive value represents the number of seconds to wait between exectutions.
# Print seconds since 1970-01-01
[epoch]
command=date +%s
interval=1A value of 0 (or undefined) means the command is not timed whatsoever and will not be executed on startup. This is useful to trigger the command only on user input (e.g. signal or click), not before.
# Restart i3 on click
[restart]
full_text=Restart
command=i3-msg -q restart
#interval=0The interval value once (or -1) will schedule the command only on startup. This tells i3blocks not to schedule the command again on a time basis. But events such as signals and clicks will execute the command again of course.
# Fetch the public IP address only on startup
[public-ip]
command=wget -qO - icanhazip.com
interval=onceThe interval value repeat (or -2) will respawn the command as soon as it terminates. This is convenient for blocking programs which exit as soon as the awaited event arises.
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Note
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clicks are not supported with this value, since such commands are unlikely to expect data on their standard input. |
# Print the last command entered in Bash
[history]
command=inotifywait -qq -e close_write ~/.bash_history; tail -1 ~/.bash_history
interval=repeatThe interval value persist (or -3) expects the command to be an infinite loop. Each line of the output will trigger an update of the block.
[window]
command=xtitle -s
interval=persistBlocks can be scheduled upon reception of a real-time signal (think prioritized and queueable). The range of available signal numbers is 1 to N, where SIGRTMIN+N = SIGRTMAX. (Note: there are 31 real-time signals in Linux.)
[caps-lock]
command=xset -q | grep Caps | awk '{ print $2, $3, $4 }'
interval=once
signal=10This example block above will be scheduled once i3blocks handles the SIGRTMIN+10 signal. This can be sent directly from an i3 binding on Caps Lock release with the following configuration:
bindsym --release Caps_Lock exec pkill -SIGRTMIN+10 i3blocksThere are several formats supported to specify which variables i3blocks must update. Some favor simplicity over flexibility but thus can be limited.
When undefined, a raw format is assumed. Each line of the output corresponds to an i3bar key, in the order of definition found in the i3bar protocol:
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the 1st line updates the full_text;
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the 2nd line updates the short_text;
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the 3rd line updates the color;
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the 4th line updates the background.
Excess lines are considered an error. Below is an example of a simple battery script.
#!/bin/bash
BAT=$(acpi -b | grep -E -o '[0-9][0-9]?%')
# Full and short texts
echo "Battery: $BAT"
echo "BAT: $BAT"
# Set urgent flag below 5% or use orange below 20%
[ ${BAT%?} -le 5 ] && exit 33
[ ${BAT%?} -le 20 ] && echo "#FF8000"
exit 0[battery]
command=battery.sh
interval=10The json format can update any variable.
[counter]
_count=0
command=printf '{"full_text":"Counter: %s", "_count":%d}\n' $_count $((_count + 1))
format=json
interval=1Optional property. Enable or disable ticker feature. Valid values are true & false.
This feature only works with the raw format. It will scroll output string char by char with given interval. Offset zeroes if there are changes in the output string.
Default value is false.
#Output string differs every minute
[ticker_test]
command=echo 'TEST_STRING-'$(date +%M)
interval=1
ticker=true
ticker_interval=2Optional property (use in conjunction with ticker). Delimeter character which separates beginning & ending of the output string. If value is set to a string containing multiple characters, only the first character will be used as the delimeter.
Default value is |.
Direction of the ticker. Valid values are right (shortcut r) & left (shortcut l).
Default value is left.
Limit of the characters to be displayed if ticker is enabled. 0 or negative values set limit to default value.
Default value is 16.
When you click on a block, data such as the button number and coordinates are merged into the block variables.
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Note
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name and instance are the two keys used by i3bar to identify a block. |
The data sent on click is detailed in the i3bar protocol.
If the block command isn’t already spawned, it is executed again.
# Print click data
[clickme]
align=center
full_text=Click me!
min_width=Button=? x=? y=?
command=echo "Button=$button x=$x y=$y"If the value of the block’s interval is persist, then the data is written on the command standard input, one line per click. What gets written depends on the block’s format. The raw format only gets the click button. The JSON format gets all block variables.
[click-loop]
full_text=Click me!
command=while read button; do echo "Got click $button"; done
interval=persist
[click-loop-json]
full_text=Click me!
command=ruby -r json -n -e '$_ = JSON.parse($_)' -e '$_["full_text"] = "Click %s at (%d,%d)" % $_.slice("button", "x", "y").values' -e 'puts JSON.dump($_)' -e 'STDOUT.flush'
interval=persist
format=jsonFrequently Asked Questions and Troubleshooting.
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What is a blocklet?
A blocklet is the configuration of a single block, part of the status line. There are plenty listed in the blocklets page.
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Can I use my own variables?
Yes, any variable defined in the block is exported as is to the environment of its command. The
foo=barproperty can be accessed with$foofrom a shell script,ENV["foo"]from Ruby, and so on.The IEEE and The Open Group state that "The name space of environment variable names containing lowercase letters is reserved for applications.". i3bar suggests to prefix your own keys with an underscore (
_), but it might be more intuitive to use uppercase environment variables, so it is your call to define your own naming convention. -
Why
$foodoesn’t work from the configuration file?i3blocks does not do string interpolation of any sort. The definitions found in the configuration file are just raw strings, this means that
bar=$bazdefines a bar variable equal to literally$baz(a dollar sign followed by "baz").String interpolation does work in the command property though, since it is interpreted by a shell which has access to the environment variables.
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How can I simulate a button?
This is pretty straightforward actually. Just make sure not to override the full_text, for example:
[calc-button] full_text=Calculator command=gnome-calculator >/dev/null
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Can a block start a GUI application?
Sure. And if you do not wish your command to block until the application is closed, ask i3 to start it for you with
i3-msg -q exec myapp. -
Why Pango isn’t working?
The Pango markup requires a Pango font. Make sure you configured i3bar to use a Pango font. For example:
font pango:Inconsolata, Icons 12 -
Why is
printfnot working?As of i3blocks 1.5, each line from a block output are expected to be terminated with a newline, e.g. with
printf "…\n"from a shell script. -
Why is the output from my persistent block not displayed?
Make sure to flush stdout, for example:
[ruby-loop] full_text=Click me command=ruby -p -e '$_.prepend("Got button ")' -e 'STDOUT.flush' interval=persist
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Can I use a time interval below 1 second?
No, the time unit for interval is the second.
But even though I wouldn’t recommend it, you can still update faster than that with loops:
[nano1] command=sleep .5; date +%N interval=repeat [nano2] command=while sleep .5; do date +%N; done interval=persist
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Can I change the block separator?
Not with i3blocks itself, separators are drawn by i3bar. You can change the separator_symbol in the i3bar configuration.
Alternatively, you can define static blocks as custom separators in your i3blocks configuration. In the example below, we use the "\xe3\x80\x89" UTF-8 character:
# Define the custom separator in global properties for boilerplate full_text=〉 align=center color=#666666 separator=false separator_block_width=7 [time] instance=la TZ=America/Los_Angeles command=date +%T interval=5 [separator] [time] instance=nc TZ=Pacific/Noumea command=date +%T interval=5 [separator] [time] instance=mtl TZ=America/Montreal command=date +%T interval=5
The log level can be increased with the -v option.
If your window manager (and thus this program) is run via systemd, you can inspect the program outputs with journalctl -t <identifier> -f.
You may also use this in conjonction with running the program manually with systemd-cat -t <identifier> ./i3blocks.
Alternatively you can redirect the standard output and error streams from the program invokation with:
bar {
status_command 2>/tmp/i3blocks.err /path/to/i3blocks -vvv -c /path/to/config | tee /tmp/i3blocks.out
}And inspect the log with tail -f /tmp/i3blocks.err.
See the manpage for details about the command line options and i3blocks usage.