Clipboard on X11, Alacritty, and Vim

Goal: Comfortably copy and paste between GUI applications in the X Window System, the Alacritty terminal, and Vim/Neovim.

Dependencies: This guide works on the X Window System, and is targetted towards Alacritty and Vim/Neovim users. You should first set up X if you have not yet done so.

References:

• ArchWiki: Clipboard: lists tools for interacting with the clipboard
• Answer to StackExchange: How to toggle or turn off text selection being sent to the clipboard: how the PRIMARY and CLIPBOARD selections work in X
• Official freedesktop.org clipboard specification: quite informative once you get paste the boring plain-text formatting

An X clipboard crash course

(To help new users coming from Windows and macOS; feel free to skip if words like “CLIPBOARD” and “PRIMARY” are familiar to you.)

TLDR: X has two clipboards, called CLIPBOARD and PRIMARY. Use CLIPBOARD for Windows/macOS-style copy and paste and PRIMARY for text selected by the mouse. End TLDR.

Windows and macOS have one system-wide clipboard. The X Window System commonly used on Linux has two¹ standardized system-wide buffers that act as independent clipboards. Loosely, in macOS/Windows terms, you basically have two clipboards. Their names are CLIPBOARD and PRIMARY, and here is what they do:

• CLIPBOARD: essentially the equivalent of the macOS or Windows clipboard. Copy text into CLIPBOARD with GUI menu options or <Ctrl>-C (or in rare cases, e.g. Alacritty, a similar keyboard shortcut), and paste from CLIPBOARD with GUI menu option, <Ctrl>-V, or a similar shortcut.

• PRIMARY: used specifically to manipulate text selected with the mouse. Any text selected by the mouse in X applications (e.g. highlighted text in a web browser) is automatically stored in PRIMARY. You paste the contents of PRIMARY with a middle mouse click.

Copying text into CLIPBOARD requires an explicit action on the user’s part (e.g. button press, keyboard shortcut), while mouse-selected text is automatically copied into PRIMARY without explicit action on the user’s part. Many users, especially those interested in a Windows/macOS-like experience, will probably use the CLIPBOARD buffer more than PRIMARY.

The rest of this article shows how to get text into and out of CLIPBOARD in various programs, allowing you to copy and paste between programs via the CLIPBOARD buffer.

GUI applications

Easiest first: in most X GUI applications (e.g. a web browser):

• Copy text into CLIPBOARD with <Ctrl>-C or a “Copy” option in a GUI menu.
• Paste text stored in CLIPBOARD with <Ctrl>-V or “Paste” menu option.

Alacritty

(This section assumes haven’t changed Alacritty’s default copy/paste key bindings, in which case you probably already knew what you were doing.)

• Copy text into CLIPBOARD with <Ctrl>-<Shift>-C (and not <Ctrl>-C like most other X applications). Alacritty intentionally avoids <Ctrl>-C for copying because <Ctrl>-C is nearly universally used to send the interrupt signal SIGINT to programs in the shell.

• Paste text stored in CLIPBOARD with <Ctrl>-<Shift>-V (and not <Ctrl>-V)

key_bindings:
    - { key: V, mods: Control|Shift, action: Paste }
    - { key: C, mods: Control|Shift, action: Copy }

Bonus: Copying with Alacritty Vi mode

If you’re familiar with Vim keybindings, you can also copy text in Alacritty using Alacritty’s Vi mode. Here are the tools you need:

• <Ctrl>-<Shift>-<Space> enters Vi mode (you can configure this key binding using the ToggleViMode action in alacritty.yml).
• Navigate with standard Vim key bindings, e.g. h, j, k, l, w, b, etc.
• v enters visual mode, from which you select the text you want to copy (V for visual line mode is also supported).
• y in visual mode copies selected text to CLIPBOARD.
• <Ctrl>-<Shift>-<Space> exits Vi mode.

Vim and Neovim

Goal: Make Vim/Neovim’s “yank”, “delete”, and “change” operations copy into the system CLIPBOARD, and make Neovim’s put (paste) operation paste from the CLIPBOARD. Example use case: copy a URL in a web browser with <Ctrl>-C, then paste the URL into Neovim with the default p action.

Requirements

Note: Vim and Neovim have different clipboard interfaces. Here’s what a typical user needs to know:

• Neovim users: Neovim communicates with the system clipboard via a clipboard provider program (see Neovim’s :help clipboard for more information). For our purposes, this means you should install a third-party clipboard provider; I suggest xclip, which you can install with

  sudo pacman -S xclip
  

  Neovim will notice xclip is installed and take care of the rest. To double check, you can use :checkhealth in Neovim to test clipboard status; an example output if xclip is correctly installed might look like this:

  ## Clipboard (optional)
    - OK: Clipboard tool found: xclip
  

• Vim users: your version of Vim must be compiled with the +X11 and +clipboard features to properly interact with the X CLIPBOARD and PRIMARY selections. You can check this by running vim --version on a command line; the output should show +X11 and +clipboard. If vim --version shows -X11 or -clipboard, you need a new version of Vim. You could either compile from source with the desired features or use the following workaround:

  1. Install gVim (a GUI-compatible version of Vim) with sudo pacman -S gvim.
  2. Remove vim if prompted by pacman about conflicting packages.
  3. Use the vim command as before; vim --version should now show +X11 and +clipboard.

  Why this works: the gvim package includes a terminal version of Vim in addition to the gVim GUI, and the terminal vim includes GUI features that regular Vim does not have.

Vim clipboard theory

Suggested prerequisite knowledge:

• The difference between X’s CLIPBOARD and PRIMARY selections (scroll up and read An X11 clipboard crash course for a refresher.)
• What Vim registers are and how to use them—a sentence like “use "ayiw to yank a word into the a register” or “use "bp to paste the contents of the b register” should make sense to you. If needed, I suggest taking a 20-minute detour and learning about registers; a good place to start might be Brian Storti’s Vim registers: The basics and beyond, then moving on to the official documentation in :help registers

Both Vim and Neovim use the * register to interact with PRIMARY and the + register to interact with CLIPBOARD. This means you can use operations like "+p to paste the contents of CLIPBOARD selection into Vim or "* to copy Vim text into the PRIMARY selection. (For documentation, see the Selection registers "* and "+ section in :help registers.)

Configure the clipboard

You can configure Vim/Neovim to use the * and/or + registers for copy and paste through the built-in clipboard option. You have three choices—in your vimrc or init.vim…

1. Use set clipboard=unnamedplus to make Vim use the + register (and thus the CLIPBOARD selection) for all yank, delete, change and put operations.

2. Use set clipboard=unnamed to make Vim use the * register (and thus the PRIMARY selection) for all yank, delete, change and put operations.

3. Use set clipboard=unnamed,unnamedplus to make Vim’s yank, delete, and change operations copy into both + and *, and make the put operations paste from +.

That should be it—Vim’s native yank/delete/change/put operations should now interact with the X CLIPBOARD and PRIMARY selections. For documentation of unnamed and unnamedplus see :help 'clipboard' (make sure to include the single quotes!). For more Vim-related copy/paste documentation than a typical user would ever want to read, check out :help 'clipboard', :help registers, :help quoteplus, and :help quotestar.

Reminder: Neovim users will need a clipboard provider (e.g. xclip) and Vim users will need a Vim with the +X11 and +clipboard features. Scroll back up to the Requirements section for a refresher.