sway-launcher-desktop

This is a TUI-based launcher menu made with bash and the amazing fzf. Despite its name, it does not (read: no longer) depend on the Sway window manager in any way and can be used with just about any WM.

Features

• Lists and executes available binaries
• Lists and executes .desktop files (entries as well as actions)
• Does not depend on xdg-utils. Just pure bash and awk
• Shows a preview window containing whatis info of binaries and the Comment= section of .desktop files
• History support which will highlight recently used entries
• Colored output and glyphs for the different entry types
• Entries are lazily piped into fzf eliminating any lag during startup
• Optional support for the XDG Autostart specification
• Executes arbitrary custom commands (if there are no other matches)

Installation

Make sure you have fzf installed and download this repository. Arch Linux users can also grab it from the AUR (thanks @turtlewit)

• sway-launcher-desktop
• sway-launcher-desktop-git

Configure it in Sway like this:

for_window [app_id="^launcher$"] floating enable, sticky enable, resize set 30 ppt 60 ppt, border pixel 10
set $menu exec $term -a launcher -e /path/to/repo/sway-launcher-desktop.sh
bindsym $mod+d exec $menu

(this example was made with term=foot in mind; it may need to be adjusted for other terminals)

You can override the default icons/glyphs by setting the appropriate GLYPH_ variable in your $menu command, e.g.:

set $menu exec $term -e env GLYPH_COMMAND="" GLYPH_DESKTOP="" GLYPH_PROMPT="? " sway-launcher

If fzf is not in your $PATH you can specify the path by supplying a value to the FZF_COMMAND variable.

set $menu exec $term -e env FZF_COMMAND="/path/to/fzf" sway-launcher

By default, the launcher will use a generic & WM-agnostic command to launch the selected program. However, it will detect if its output is being piped to another program and merely print the selected command in that case - instead of launching it by itself. You can use this to integrate the launcher with other tools. For example, if you wish to launch your programs with swaymsg exec, you can do that like this¹:

 swaymsg exec "$(./sway-launcher-desktop.sh)"

Set up a Terminal command

Some of your desktop entries will probably be TUI programs that expect to be launched in a new terminal window. Those entries have the Terminal=true flag set and you need to tell the launcher which terminal emulator to use. Pass the TERMINAL_COMMAND environment variable with your terminal startup command to the script to use your preferred terminal emulator. The script will default to $TERMINAL -e

Configure application autostart

If you want to be able to autostart applications , this script provides a function to handle them for you. Simply run sway-launcher-desktop.sh autostart in your .bashrc, at the end of your i3/sway config, or wherever else you deem fit.

Configure fzf preview window

You can configure the fzf preview window using the environment variable PREVIEW_WINDOW (default: up:2:noborder). For example, if you prefer a taller window, you could use PREVIEW_WINDOW=5:up. The content of PREVIEW_WINDOW is passed to the --preview-window option, so check out the fzf manual for further details.

Extending the launcher

In addition to desktop application entries and binaries, you can extend sway-launcher-desktop with custom item providers. It will read the configuration of custom item providers from $HOME/.config/sway-launcher-desktop/providers.conf. The structure looks like this:

[my-provider]
list_cmd=echo -e 'my-custom-entry\034my-provider\034  My custom provider'
preview_cmd=echo -e 'This is the preview of {1}'
launch_cmd=notify-send 'I am now launching {1}'
purge_cmd=command -v '{1}' || exit 43

The list_cmd generated the list of entries. For each entry, it has to print the following columns, separated by the \034 field separator character:

1. The item to launch. This will get passed to preview_cmd and launch_cmd as {1}
2. The name of your provider (the same as what what you put inside the brackets, so my-provider in this example)
3. The text that appears in the fzf window. You might want to prepend it with a glyph and add some color via ANSI escape codes
4. (optional) Metadata that you can pass to preview_cmd and launch_cmd as {2}. For example, this is used to specify a specific Desktop Action inside a .desktop file

The preview_cmd renders the contents of the fzf preview panel. You can use the template variable {1} in your command, which will be substituted with the value of the selected item.

The launch_cmd is fired when the user has selected one of the provider's entries.

The purge_cmd is used as part of the purge function. It tests any entry of a provider. If the test exits with 43, then the entry will be removed from the history file

Note: Pass the environment variable PROVIDERS_FILE to read custom providers from another file than the default providers.conf. The path in PROVIDERS_FILE can either be absolute or relative to ${HOME}/.config/sway-launcher-desktop/.

Keeping builtin providers

When a custom provider config is used, the default behaviour is to replace the hardcoded builtins. This is not always desirable if you merely wish to add something new. Luckily, the built-in providers only call specific functions of the main script, which are also accessible externally. So you can simply mimick their behaviour by placing this in your config file:

[desktop]
list_cmd=/path/to/sway-launcher-desktop.sh list-entries
preview_cmd=/path/to/sway-launcher-desktop.sh describe-desktop "{1}"
launch_cmd=/path/to/sway-launcher-desktop.sh run-desktop '{1}' {2}
purge_cmd=test -f '{1}' || exit 43

[command]
list_cmd=/path/to/sway-launcher-desktop.sh list-commands
preview_cmd=/path/to/sway-launcher-desktop.sh describe-command "{1}"
launch_cmd=$TERMINAL_COMMAND {1}
purge_cmd=command -v '{1}' || exit 43

Launcher history file

By default, sway-launcher-desktop stores a history of commands to make frequently used entries available more quickly. This history is stored in a file in ~/.cache/ (or $XDG_CACHE_HOME, if that environment variable is set). You may change the file path and name by setting the environment variable HIST_FILE to the desired path. Setting the variable to an empty value disables the history feature entirely.

Housekeeping

After a while, this history might grow and contain some invalid entries due to removed/renamed programs etc. You can use ./sway-launcher-desktop.sh purge to identify broken entries and remove them. Consider adding this command to a cronjob, startup script, or maybe even hook it into your package manager.

Troubleshooting

Debug information is directed to file descriptor 3 and can be dumped using ./sway-launcher-desktop.sh 3>> ~/sway-launcher-desktop.log

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¹ If you want to use this as a keybinding though, this kind of shell substitution will not work inside the config file. Here's a way to make it work