Repository files navigation

Helic is a tool for synchronizing clipboard contents acrossX11,tmux and network, consisting of a daemonlistening for changes and a CLI client for use in programs likeNeovim.

X11 has three separate copy buffers, called theclipboard, theprimary selection and thesecondary selection.Selections are used when text is selected with the mouse, while the clipboard is updated byCtrl-C.

When some text is copied or selected inX11, the daemon receives an event that it proceeds to broadcast to theconfigured targets.If the source was a selection, theX11 clipboard is updated as well.

The CLI programhel can be used to manually send text to the daemon, for example fromtmux orNeovim.If remote hosts are configured, each yank event is sent over the network to update their clipboards.

Several yank events are stored in memory in order to detect duplicates and cycles.

The CLI understands four different commands:

Thelist command will print a table like this:

╭───┬──────────┬───────┬──────────┬──────────────────────────╮│ # │ Instance │ Agent │   Time   │         Content          │╞═══╪══════════╪═══════╪══════════╪══════════════════════════╡│ 2 │   test   │ nvim  │ 12:00:00 │ single line              │├───┼──────────┼───────┼──────────┼──────────────────────────┤│ 1 │   test   │ nvim  │ 12:00:00 │ single line with newline │├───┼──────────┼───────┼──────────┼──────────────────────────┤│ 0 │   test   │ nvim  │ 12:00:00 │ three lines 1 [3 lines]  │╰───┴──────────┴───────┴──────────┴──────────────────────────╯

The index in the first column, with 0 being the latest event, can be used withhel load.

The project uses aNixflake to configure its build, and it is recommended to install or run it usingNix as well.IfNix is installed and configured for use withflakes, the app can be run without installation like this:

$ nix run github:tek/helic -- listen$echo'yank me'| nix run github:tek/helic -- yank --agent cli$ nix run github:tek/helic -- list 100$ nix run github:tek/helic -- load 5

The flake provides aNixOS module that can be used by adding it to/etc/nixos/flake.nix:

{inputs.helic.url="github:tek/helic";outputs={nixpkgs,helic, ...}:{nixosConfigurations.myhost=nixpkgs.lib.nixosSystem{modules=[helic.nixosModules.default];services.helic.enable=true;};};}

With this, asystemd user service will be started on login and the client will be in$PATH:

$echo'yank me'| hel yank$ hel yank --agent custom-name --text'yank me'

After a rebuild, the service may not be started right away, so this command must be executed:

$ systemctl --user start helic

Globally enabledsystemd user services are started for all users on login.To prevent that, you can set the module optionservices.helic.user = "myuser".

Alternatively, the app can be installed using aHaskell package manager, likeCabal:

$ cabal install helic$ hel listen

If no command has been specified explicitly,Helic decides which one to start by the presence of stdin data:

$ hel# start daemon$echo'yank me'| hel# yank

Global CLI options are specifiedbefore the command name, command-specific ones after it.

The app reads the first existing one of these three configuration files:

• The file specified with--config-file
• $XDG_CONFIG_DIR/helic.yaml (most likely~/.config/helic.yaml)
• /etc/helic.yaml

An example config file looks like this:

name:myhostmaxHistory:1000debounceMillis:3000verbose:truenet:enable:trueport:10001hosts:    -"remote1:1000"    -"remote2:2000"timeout:5tmux:enable:trueexe:/bin/tmuxx11:enable:truedisplay:":0"

ForNixOS, the file/etc/helic.yaml is generated from module options:

{services.helic={enable=true;name="myhost";maxHistory=1000;debounceMillis=3000;verbose=true;user="myuser";net={enable=true;port=10001;hosts=["remote1:1000""remote2:2000"];timeout=5;};tmux={enable=true;package=pkgs.tmux;};x11={enable=true;display=":0";};};}

The meaning of these options is:

Neovim's clipboard requires configuration with a tool in any case, so changing it to usehel is simple:

letg:clipboard= {\'name':'helic',\'copy': {\'+':'hel yank --agent nvim',\'*':'hel yank --agent nvim',\   },\'paste': {\'+':'xsel -bo',\'*':'xsel -bo',\  },\}

SinceHelic updates theX11 clipboard, a custompaste command is not necessary.