🖩 Do live calculations in rofi!

A rofi plugin that uses qalculate's qalc to parse natural language input and provide results.

Since this uses qalculate's amazing qalc you can try natural language queries such 500 + 25% or 5000 EUR to USD or 150 to hex. It can also solve linear equations on the fly. Try 60x + 30 = 50, for instance.

Run rofi like:

rofi -show calc -modi calc -no-show-match -no-sort

The result of the current input can be selected with Ctrl+Return, and history entries can be selected with Return. By default this will just output the equation/result.

The history file by default sits at $HOME/.local/share/rofi/rofi_calc_history in case you ever need to delete it or change it manually. You can disable persistent history if you don't like that.

• Arch Linux
• FreeBSD
• Gentoo
• openSUSE

You need a C compilation toolchain (a cc, autoconf, pkg-config, ...), rofi (version >= 1.5) as well as qalculate (version > 2.0).

You will also need development headers for rofi. Depending on your distribution these may be included in different packages:

• Arch Linux, Gentoo: included with rofi, libqalculate
• OpenSUSE: zypper in rofi rofi-devel qalculate
• Debian: apt install rofi-dev qalc libtool libtool-bin
• Ubuntu: apt install rofi-dev qalc libtool
• Solus: eopkg it rofi-devel libqalculate
• CentOS, Fedora: Install qalculate (find rofi-devel headers yourself)
• Others: look it up :)

Some distributions ship an extremely outdated version of qalculate so you might have to compile your own. If that is the case, see here.

rofi-calc uses autotools as build system. If installing from git, the following steps should install it:

$ git clone https://github.com/svenstaro/rofi-calc.git
$ mkdir m4
$ autoreconf -i
$ mkdir build
$ cd build/
$ ../configure
$ make
$ make install

• Use the -qalc-binary option to specify the name or location of qalculate's qalc binary. Defaults to qalc.

• Use the -terse option to reduce the output of qalc to just the result of the input expression.

• Use the -no-unicode option to disable qalc's Unicode mode.

• Use the -calc-command option to specify a shell command to execute which will be interpolated with the following keys:

  • {expression}: the left-side of the equation (currently not available when using -terse)
  • {result}: the right of the equation

  The following example copies the result to the clipboard upon pressing the key combination defined by -kb-accept-custom (by default Control+Return). NOTE: {result} should be quoted since it may contain characters that your shell would otherwise interpret:

    rofi -show calc -modi calc -no-show-match -no-sort -calc-command "echo -n '{result}' | xclip"
  

  Alternatively, this example would immediately type out the result (using xdotool) wherever your cursor currently is (upon pressing Control+Return/-kb-accept-custom):

    rofi -modi calc -show calc -calc-command 'xdotool type --clearmodifiers "{result}"'
  

• The -calc-command-history option will additionally add the output of qalc to history when the -calc-command is run. This will have no effect if -no-history is enabled.

• It's convenient to bind it to a key combination in i3. For instance, you could use:

    bindsym $mod+c exec --no-startup-id "rofi -show calc -modi calc -no-show-match -no-sort > /dev/null"
  

• To disable the bold font applied to the results by default, you can use the flag -no-bold and run rofi like:

    rofi -show calc -modi calc -no-show-match -no-sort -no-bold
  

• To disable persistent history, use -no-persist-history:

    rofi -show calc -modi calc -no-show-match -no-sort -no-persist-history
  

  This will disable writing and loading the history file and thus you'll lose and entered entries upon quitting rofi-calc.

• To disable the history entirely, use -no-history:

    rofi -show calc -modi calc -no-show-match -no-sort -no-history -lines 0
  

  The benefit of this is that you can simply enter a term and press Return and that'll already act on the result by printing it to stdout or via -calc-command if configured.

• To automatically save last calculation to the history on rofi close, use -automatic-save-to-history.:

    rofi -show calc -modi calc -no-show-match -no-sort -automatic-save-to-history
  

  This means that calculations are put into history even if you don't press Return.

• To enable thousand separators in the output (e.g. 5 * 12 = 6,000, rather than 6000) add the following to ~/.config/qalculate/qalc.cfg

  • For , separator:

      digit_grouping=2
    

  • For space separator:

      digit_grouping=1
    

• To use a different output format for numeric representations (for instance, some locales use , instead of . as a decimal separator), set LC_NUMERIC to a different value like this:

    LC_NUMERIC=de_DE.UTF-8 rofi -show calc -modi calc -no-show-match -no-sort
  

• To set a different default locale, set your LC_MONETARY variable:

    LC_MONETARY=de_DE.UTF-8 rofi -show calc -modi calc -no-show-match -no-sort
  

  Make sure the locale is actually available on your system!

• Use the -hint-result option to specify the text of the hint before result.

• Use the -hint-welcome option to specify the welcome text.

If you're developing this, it might be helpful to start rofi directly with a locally compiled plugin like this:

autoreconf -i
mkdir build
cd build
../configure
make
rofi -plugin-path .libs -show calc -modi calc -no-show-match -no-sort