# Installation

## Prerequisites

Obviously to use the Emacs Prelude you have to install Emacs
first. We'll assume you can manage this part on your own.
Aim for the newest stable Emacs release, although as a rule of
thumb Prelude aims to support the last 2-3 stable releases.

For spell-checking to work you should install `aspell`, together with its
dictionaries for the languages you wish to check.

You'll also do well to install some of the following:

* `git` (needed by Magit)
* `ag` (`the_silver_searcher`) or `ripgrep` (Projectile has nice integration with them and they are much faster than `grep`)
* your favorite lint tools (for Flycheck)

All those tools are completely optional, though.

!!! Note

    Additional external tools might be needed by some of the modules (e.g. tools specific to particular programming languages, etc).

## Installation

### Automated

You can install Emacs Prelude via the command line with either `curl` or
`wget`. Naturally `git` is also required.

The installer script will do the following:

* Clone Prelude's GitHub repo
* Check your Emacs version
* Backup any existing `.emacs` or `.emacs.d` you might have
* Create any additional folders if necessary (e.g. for storing package-specific data)

If you have a `.emacs` file it will backed up as `.emacs.pre-prelude` and if you have
a `.emacs.d` folder, it will be backed up as `.emacs.d.pre-prelude.tar`.

#### Via Curl

If you're using `curl` type the following command:

```shellsession
$ curl -L https://github.com/bbatsov/prelude/raw/master/utils/installer.sh | sh
```

#### Via Wget

If you're using `wget` type:

```shellsession
$ wget --no-check-certificate https://github.com/bbatsov/prelude/raw/master/utils/installer.sh -O - | sh
```

### Manual

Make sure you do not have any `~/.emacs` file or `~/.emacs.d` folder present.

```shellsession
$ git clone git://github.com/bbatsov/prelude.git path/to/local/repo
$ ln -s path/to/local/repo ~/.emacs.d
$ cd ~/.emacs.d
```

!!! Note

    If you are using Windows, you should check what Emacs thinks the `~` directory is by running Emacs
    and typing `C-x d ~/<RET>`, and then adjust the command appropriately.

### Site Wide
For a multi-user environment, as an admin, the customizations intended
for all users go in the site-start file represented by the variable
`site-run-file`, while single users will use their own init file
represented by the variable `user-init-file`.

If you have placed your prelude directory in `/opt/prelude` then,
append the following line to the `site-start.el`

``` emacs-lisp
(load "/opt/prelude/init.el")
```

If you are using emacs as a daemon process, with other users or daemon
processes interacting with the emacs daemon (e.g. Emacs is your window
manager) then the `site-lisp` directory could be the right place to
place your configuration files.

## Updating Prelude

### Manual update

The update procedure is fairly straightforward and consists of 3 steps:

#### Update all bundled packages

Just run <kbd>M-x package-list-packages RET U x</kbd>.

#### Update Prelude's code

```shellsession
$ cd path/to/prelude/installation
$ git pull
```

The `path/to/prelude/installation` is usually `~/.emacs.d` (at least
on Unix systems).

#### Restart Prelude

It's generally a good idea to stop Emacs after you do the update. The
next time Prelude starts it will install any new dependencies (if
there are such).

### Automatic update

Simply run <kbd>M-x prelude-update</kbd> from Emacs itself and restart Emacs afterwards.

## Pinning packages

By default, Prelude will install packages from the MELPA and GNU ELPA package
repositories. Occasionally package integration can break when upgrading packages,
as the packages in the MELPA repository are all snapshot builds.
This can be avoided by pinning packages to stable versions in other repositories (e.g. MELPA Stable).
To do so, copy `prelude-pinned-packages.el` from the sample directory to
Prelude's root directory and adjust the [variables](https://www.gnu.org/software/emacs/manual/html_node/emacs/Package-Installation.html)
inside accordingly.

## Enabling additional modules

By default most of the modules that ship with Prelude are not loaded. For more information on the functionality provided by these modules visit the [docs](modules/index.md).

```lisp
;;; Uncomment the modules you'd like to use and restart Prelude afterwards

(require 'prelude-c)
;; (require 'prelude-clojure)
;; (require 'prelude-coffee)
;; (require 'prelude-common-lisp)
;; (require 'prelude-css)
(require 'prelude-emacs-lisp)
(require 'prelude-erc)
;; (require 'prelude-erlang)
;; (require 'prelude-elixir)
;; (require 'prelude-haskell)
(require 'prelude-js)
;; (require 'prelude-latex)
(require 'prelude-lisp)
(require 'prelude-org)
(require 'prelude-perl)
;; (require 'prelude-python)
;; (require 'prelude-ruby)
;; (require 'prelude-scala)
(require 'prelude-scheme)
;; (require 'prelude-scss)
;; (require 'prelude-web)
(require 'prelude-xml)
```

You'll need to adjust your `prelude-modules.el` file once the installation is done.

In case of an automated installation, you'll find this file in the `personal` directory of your Emacs installation.

If you are doing a manual install then you first
need to copy the `prelude-modules.el` available in the sample
directory to the root of `path/to/prelude/installation` and then
adjust that one.

After you've uncommented a module you should either restart Emacs or evaluate the module
`require` expression with <kbd>C-x C-e</kbd>.

## Uninstalling Prelude

Provided you've installed Prelude in `.emacs.d`, all you need to do is delete that folder.
If you opted for the manual installation and making `.emacs.d` a symlink - you remove/update
the link. Yeah, it's as simple as that. No fancy uninstaller required!