alacritty/README.md

Alacritty
=========

[![Build Status](https://travis-ci.org/jwilm/alacritty.svg?branch=master)](https://travis-ci.org/jwilm/alacritty)

Alacritty is the fastest terminal emulator in existence. Using the GPU for
rendering enables optimizations that simply aren't possible in other emulators.
Alacritty currently supports macOS and Linux, and Windows support is planned
before the 1.0 release.

<p align="center">
  <img width="600" alt="Alacritty running vim inside tmux" src="https://cloud.githubusercontent.com/assets/4285147/21585004/2ebd0288-d06c-11e6-95d3-4a2889dbbd6f.png">
</p>

## About

Alacritty is focused on simplicity and performance. The performance goal means
it should be faster than any other terminal emulator available. The simplicity
goal means that it doesn't have features such as tabs or splits (which can be
better provided by a window manager or [terminal multiplexer][tmux]) nor
niceties like a GUI config editor.

The software is considered to be at an **alpha** level of readiness--there are
missing features and bugs to be fixed, but it is already used by many as a daily
driver.

Precompiled binaries will eventually be made available on supported platforms.
This is minimally blocked on a stable config format. For now, Alacritty must be
built from source.

## Further information

- [Announcing Alacritty, a GPU-Accelerated Terminal Emulator](http://blog.jwilm.io/announcing-alacritty/) January 6, 2017
- [A short talk about Alacritty at the Rust Meetup January 2017](https://air.mozilla.org/rust-meetup-january-2017/) (starts at 57:00)

## Installation

Instructions are provided for macOS and many Linux variants to compile Alacritty
from source. With the exception of Arch (which has a package in the AUR) and
[NixOS](https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/misc/alacritty/default.nix)
(at the moment in unstable, will be part of 17.09), please first read the
[prerequisites](#prerequisites) section, then find the section for your OS, and
finally go to [building](#building) and [configuration](#configuration).


### Arch Linux

```sh
git clone https://aur.archlinux.org/alacritty-git.git
cd alacritty-git
makepkg -isr
```


## Manual Installation

### Prerequisites

1. Alacritty requires most recent stable Rust compiler. If your distribution provides it as a package (e.g. `rust` on Arch Linux), install it with the package manager. Alternatively see below on how to install it with `rustup`.

    Note: **DO NOT** use the Homebrew Rust compiler on macOS (see FAQ for explanation).

#### Installing Rust compiler with `rustup`

1. Install [`rustup.rs`](https://rustup.rs/). 

2. Clone the source code:

   ```sh
   git clone https://github.com/jwilm/alacritty.git
   cd alacritty
   ```

3. Make sure you have the right Rust compiler installed. Run

   ```sh
   rustup override set stable
   rustup update stable
   ```

#### Ubuntu

On Ubuntu, you need a few extra libraries to build Alacritty. Here's an `apt`
command that should install all of them. If something is still found to be
missing, please open an issue.

```sh
apt-get install cmake libfreetype6-dev libfontconfig1-dev xclip
```

#### Arch Linux

On Arch Linux, you need a few extra libraries to build Alacritty. Here's a
`pacman` command that should install all of them. If something is still found
to be missing, please open an issue.

```sh
pacman -S cmake freetype2 fontconfig pkg-config make xclip
```

#### Fedora

On Fedora, you need a few extra libraries to build Alacritty. Here's a `dnf`
command that should install all of them. If something is still found to be
missing, please open an issue.

```sh
dnf install cmake freetype-devel fontconfig-devel xclip
```

#### openSUSE

On openSUSE, you need a few extra libraries to build Alacritty. Here's
a `zypper` command that should install all of them. If something is
still found to be missing, please open an issue.

```sh
zypper install cmake freetype-devel fontconfig-devel xclip
```

#### Slackware

Compiles out of the box for 14.2
For copy & paste support (middle mouse button) you need to install xclip
https://slackbuilds.org/repository/14.2/misc/xclip/?search=xclip


#### Void Linux

On [Void Linux](https://voidlinux.eu), install following packages before
compiling Alacritty:

```sh
xbps-install cmake freetype-devel freetype expat-devel fontconfig xclip
```

#### FreeBSD

On FreeBSD, you need a few extra libraries to build Alacritty. Here's a `pkg`
command that should install all of them. If something is still found to be
missing, please open an issue.

```sh
pkg install cmake freetype2 fontconfig xclip pkgconf
```

#### Solus

On [Solus](https://solus-project.com/), you need a few extra libraries to build Alacritty. Here's a
`eopkg` command that should install all of them. If something is still found
to be missing, please open an issue.

```sh
sudo eopkg install freetype2-devel fontconfig-devel
```

### NixOS/Nixpkgs

The following command can be used to get a shell with all development dependencies on [NixOS](https://nixos.org).

```
nix-shell -A alacritty '<nixpkgs>'
```

#### Gentoo

On Gentoo, there's a portage overlay available. Make sure `layman` is installed
and run:
```
sudo layman -a slyfox
```
Then, add `x11-terms/alacritty **` to `/etc/portage/package.accept_keywords` 
and emerge alacritty:
```
sudo emerge alacritty
```
It might be handy to mask all other packages provided in the `slyfox` overlay by
adding `*/*::slyfox` to `/etc/portage/package.mask` and adding
`x11-terms/alacritty::slyfox` to `/etc/portage/package.unmask`.

#### Other

If you build Alacritty on another distribution, we would love some help
filling in this section of the README.

### Building

Once all the prerequisites are installed, compiling Alacritty should be easy:

```sh
cargo build --release
```

If all goes well, this should place a binary at `target/release/alacritty`.
**BEFORE YOU RUN IT:** Install the config file as described below; otherwise,
many things (such as arrow keys) will not work. If you're on macOS, you'll need
to change the `monospace` font family to something like `Menlo`.

### Desktop Entry

Many linux distributions support desktop entries for adding applications to
system menus. To install the desktop entry for Alacritty, run

```sh
sudo cp target/release/alacritty /usr/local/bin # or anywhere else in $PATH
cp Alacritty.desktop ~/.local/share/applications
```

To build an application for macOS, run

```sh
make app
cp -r target/release/osx/Alacritty.app /Applications/Alacritty.app
```

## Configuration

Although it's possible the default configuration would work on your system,
you'll probably end up wanting to customize it anyhow. There is a default
`alacritty.yml` at the git repository root. Alacritty looks for the
configuration file as the following paths:

1. `$XDG_CONFIG_HOME/alacritty/alacritty.yml`
2. `$XDG_CONFIG_HOME/alacritty.yml`
3. `$HOME/.config/alacritty/alacritty.yml`
4. `$HOME/.alacritty.yml`

If neither of these paths are found then `$XDG_CONFIG_HOME/alacritty/alacritty.yml`
is created once alacritty is first run. On most systems this often defaults
to `$HOME/.config/alacritty/alacritty.yml`.

Many configuration options will take effect immediately upon saving changes to
the config file. The only exception is the `font`, `dimensions` and `dpi`
sections which requires Alacritty to be restarted. For further explanation of
the config file, please consult the comments in the default config file.

## Issues (known, unknown, feature requests, etc)

If you run into a problem with Alacritty, please file an issue. If you've got a
feature request, feel free to ask about it. Keep in mind that Alacritty is very
much not looking to be a feature-rich terminal emulator with all sorts of bells
and widgets. It's primarily a cross-platform, blazing fast `tmux` renderer that
Just Works.

## FAQ

- _proc-macro derive panicked during macOS build; what's wrong?_ There's an
  issue with the Rust compiler from Homebrew. Please follow the instructions
  and use `rustup`.
- _Is it really the fastest terminal emulator?_ In the terminals I've
  benchmarked against, alacritty is either faster, WAY faster, or at least
  neutral. There are no benchmarks in which I've found Alacritty to be slower.
- _macOS + tmux + vim is slow! I thought this was supposed to be fast!_ This
  appears to be an issue outside of terminal emulators; either macOS has an IPC
  performance issue, or either tmux or vim (or both) have a bug. This same issue
  can be seen in `iTerm2` and `Terminal.app`. I've found that if tmux is running
  on another machine which is connected to Alacritty via SSH, this issue
  disappears. Actual throughput and rendering performance are still better in
  Alacritty.
- _Is wayland supported?_ Not yet. Alacritty is currently on a fork of glutin
  that needs some updates to work with Wayland. To stop glutin from detecting
  Wayland (e.g. for use on XWayland) launch Alacritty like this:
  `env WAYLAND_DISPLAY= alacritty`
- _When will Windows support be available?_ When someone has time to work on it.
  Contributors would be welcomed :).
- _My arrow keys don't work_. It sounds like you deleted some key bindings from
  your config file. Please reference the default config file to restore them.
- _Why doesn't it support scrollback?_ Alacritty's original purpose was to
  provide a better experience when using [tmux] which already handled
  scrollback. The scope of this project has since expanded, and [scrollback will
  eventually be added](https://github.com/jwilm/alacritty/issues/124).

## IRC

Alacritty discussion can be found in `#alacritty` on freenode.

## License

Alacritty is released under the [Apache License, Version 2.0].

[Apache License, Version 2.0]: https://github.com/jwilm/alacritty/blob/readme/LICENSE-APACHE
[tmux]: https://github.com/tmux/tmux