el-get.texi

\input texinfo.tex    @c -*-texinfo-*-
@c %**start of header
@setfilename el-get.info
@settitle El-Get User Manual
@c @documentencoding utf-8
@c %**end of header

@dircategory Emacs
@direntry
* El-Get: (el-get).        Using el-get to manage your Emacs Extensions.
@end direntry

@copying
Copyright @copyright{} 2010, 2011, 2012 Dimitri Fontaine.

@quotation
            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
                    Version 2, December 2004

 Copyright (C) 2004 Sam Hocevar @email{sam@@hocevar.net}

 Everyone is permitted to copy and distribute verbatim or modified
 copies of this license document, and changing it is allowed as long
 as the name is changed.

            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

  0. You just DO WHAT THE FUCK YOU WANT TO.
@end quotation
@end copying

@node Top
@top El-Get User Manual

El-Get is an Emacs Extension manager that allows you to install,
update and remove external Emacs Lisp extensions. More importantly,
El-Get will care about initializing installed extensions for you at
Emacs Startup.

@menu
* Introduction::
* Acknowledgments::
* Glossary::
* Installing::
* Usage::
* Setup::
* User Init::
* Recipes::
* Authoring Recipes::
@end menu

@node Introduction
@chapter Introduction

El-Get allows you to install and manage Emacs Lisp code for Emacs. It
supports lots of differents types of sources and is able to install
them, update them and remove them, and more importantly it will init
them for you.

That means it will @code{require} the @code{features} you need,
@code{load} the necessary files, set the @code{Info} paths so that
@kbd{C-h i} shows the new documentation you now depend on, and finally
call your own @code{post-init} function for you to setup the
extension. Or call it a package.

El-Get Version String (@code{M-x el-get-version}) are now inspired by
how Emacs itself numbers its versions.  First is the major version
number, then a dot, then the minor version number.  The minor version
number is 0 when still developping the next major version.  So 3.0 is
a developer release while 3.1 is a stable release.

Please note that this versioning policy has been picked while backing
1.2~dev, so 1.0 was a "stable" release in fact.  Ah, history.

@node Acknowledgments
@chapter Acknowledgments

Dimitri Fontaine started the whole project and still manages the
releases, and sometimes even contribute code and documentation.

Julien Danjou has been a contributor since very early days, about the
first beta tester of the idea, before we really knew how much to
achieve.

Ryan C. Thompson joined and commented some issues, began contributing
and quickly became top-level and most active contributor to the
project, getting a commit bit and some management duties. He manages
tests and issues on github as much as he can spares time to El-Get.

Dave Abrahams contributed lots of code and efforts to make things
right™. He's still using El-Get, but decided to retire from the
project.

Lots of people (more than we can list here) did contribute to El-Get
either recipes, bug fixes or ideas to implement, often with code. That
builds up an awesome community, thanks guys!

@example
dim ~/dev/emacs/el-get git --no-pager shortlog -n -s | wc -l
     137
dim ~/dev/emacs/el-get git --no-pager shortlog -n -s | head -10
   734	Dimitri Fontaine
   336	Ryan C. Thompson
   114	Julien Danjou
   110	Dave Abrahams
    73	Ryan Thompson
    72	Sébastien Gross
    42	Takafumi Arakaki
    27	Alex Ott
    25	Yakkala Yagnesh Raghava
    21	Rüdiger Sonderfeld
@end example

@node Glossary
@chapter Glossary

@table @asis

@item Autoload
Delay loading a package definition until its first use.

@item Build
Action that happens at @xref{Glossary - Install}, and @xref{Glossary -
Update}. Packages might skip any @code{build} step entirely. When
given, the build step allows to run system level tools (think
@code{make}), often to produce to derivative files.

@item Byte-Compile
Action to compile Emacs Lisp files so that loading them is
faster. El-Get is able to automatically manage that step at install
and update time so that init time is faster, see @xref{Glossary -
Init}.

@item Dependency
Any El-Get package can depend on some others. At install time, El-Get
will make sure all dependant packages are installed first. At init
time, same thing will happen. Dependency management is solved with a
topological sort so that if you install a package @code{a} that
depends on a package @code{b} that depends on a package @code{c},
El-Get will install @code{c} then @code{b} then @code{a}.

@anchor{Glossary - Init}
@item Init
When you start Emacs you want your packages to get setup and ready to
serve whatever usage you have of this advanced Operating
System. El-Get calls this setup step the @code{init} and will care
about initializing your packages automatically given a @xref{Glossary
- Recipe}.

@anchor{Glossary - Install}
@item Install
El-Get install a package by fetching its sources as described in the
package recipe, then running the build steps if the recipe contains
such.

@item Method
An El-Get method is a backend code providing facilities to fetch,
install, update and remove external code. El-Get currently implements
methods that targets @code{apt-get}, @code{brew}, @code{builtin},
@code{bzr}, @code{cvs}, @code{darcs}, @code{elpa}, @code{emacsmirror},
@code{emacswiki}, @code{fink}, @code{fossil}, @code{git} and
@code{git-svn}, @code{github} @code{github-tar} and @code{github-zip},
@code{hg}, @code{http} @code{http-tar} and @code{http-zip},
@code{pacman} and @code{svn}.

@item Notification
El-Get notifies its user when a package is done installing, updating
or removing. It knows how to use several system level notification
facilities, such as @code{DBUS} or @command{growl}.

@item Package
A package is what El-Get manages for you. It's a set of Emacs Lisp
files (possible a set of a single file, possibly with some Info
documentation and build scripts, etc) that El-Get knows how to fetch
and install, update and remove, and init at Emacs Startup.

@anchor{Glossary - Recipe}
@item Recipe
An El-Get recipe describes a package in terms that allow El-Get to
provide its features against that package. It's easy enough to write
recipes, and fun to share them!

@item Remove
El-Get removes a package by simple removing the directory where the
package is installed. If you want the features of the package to get
unloaded, most often the easier way to do that is to restart Emacs.

@anchor{Glossary - Status}
@item Status
One of @code{available}, @code{installed}, @code{required} or
@code{removed}. When El-Get is asked to install a package, the status
is set to @code{required} before to fetch and build it, so that in
case of error the system knows to try installing again.

@anchor{Glossary - Update}
@item Update
El-Get updates a package in different ways, depending on the package
type and the associated method. In some cases it's not possible to
update a package, like when it switched from @code{svn} to @code{git}
for example.

@end table

@node Installing
@chapter Installing

El-Get comes with a @code{*scratch*}-installer. Ideally you would
install El-Get with El-Get itself, but I couldn't figure out how to do
that, so instead you have to copy and paste the following code into
your @code{*scratch*} buffer and evaluate it:

@example
;; So the idea is that you copy/paste this code into your *scratch* buffer,
;; hit C-j, and you have a working el-get.
(url-retrieve
 "https://raw.github.com/dimitri/el-get/master/el-get-install.el"
 (lambda (s)
   (goto-char (point-max))
   (eval-print-last-sexp)))
@end example

To evaluate that code, you place the point at the end of the text
block (just after the last closing paren) and you type @kbd{C-j}.

@menu
* Install the developper version::
* Skip Emacswiki recipes when installing::
@end menu

@node Install the developper version
@section Developper version

The lazy installer uses the default @file{el-get-install.el} file
which targets the @code{stable} branch.  To install El-Get directly on
the @code{master} branch, summon the @code{el-get-master-branch}
variable into existence:

@example
;; So the idea is that you copy/paste this code into your *scratch* buffer,
;; hit C-j, and you have a working developper edition of el-get.
(url-retrieve
 "https://raw.github.com/dimitri/el-get/master/el-get-install.el"
 (lambda (s)
   (let (el-get-master-branch)
     (goto-char (point-max))
     (eval-print-last-sexp))))
@end example

@node Skip Emacswiki recipes when installing
@section Skip Emacswiki recipes when installing

The installer will fetch from emacswiki all the recipe available there
and install a local copy of those in your system automatically. Should
you want to disable that feature, the following snippet is showing how
to:

@example
;; So the idea is that you copy/paste this code into your *scratch* buffer,
;; hit C-j, and you have a working el-get (without emacswiki automatic
;; recipes).
(url-retrieve
 "https://raw.github.com/dimitri/el-get/master/el-get-install.el"
 (lambda (s)
   (let (el-get-install-skip-emacswiki-recipes)
     (goto-char (point-max))
     (eval-print-last-sexp))))
@end example

@node Usage
@chapter Usage

Now that El-Get is installed, simply use @code{M-x el-get-install} and
pick whatever package you need.

Here's a list of commands provided by El-Get:

@table @code

@item el-get-list-packages
List all available packages with their names, @xref{Glossary -
Status}, and description. Name and description are taken from the
recipe file of the package.

You can find which recipe file is used for a given package using
@code{el-get-find-recipe-file} or @code{el-get-describe}.

@item el-get-describe
Offers a full text description of a package with buttons to install,
remove and update, and with the recipe content.

@item el-get-find-recipe-file
Find the recipe file for given recipe, prompted.

@item el-get-install
Install given package, as prompted.

@item el-get-init
Initialize given package, as prompted. If some user code is setup to be
run at initialisation, it will get run by this command. See @xref{User
Init}.

@item el-get-update
Update a given package, as prompted. In some cases a straight update
is not possible (recipe switched from CVS to git is a common
reason). El-Get will try and detect such cases and do
@code{el-get-remove} then @code{el-get-install} if necessary.

Please realise that updating packages might break your current package
setup and that you will have to revisit your setup accordingly.

@item el-get-remove
Remove given package, as prompted.

@item el-get-self-update
Update El-Get itself, and force that update to be synchronous. That
allows to make sure you're not updating El-Get code while trying to
update or install some other package at the same time.

@item el-get-update-all
Will update all packages that have the @code{installed} status in your
status file.  Before the update you will be prompted for confirmation
that you wish to proceed.

Beware that using this function can lead to hours of settings review:
more often than not updating a package requires some adjustments to
your setup.  Updating all of them at once will require reviewing
almost all your setup.

@item el-get-reload

Reload the given package files.  Happens automatically at update time
too.

@end table

@node Setup
@chapter Setup

El-Get setup can be very simple or arbitrarily complex. This chapter
explains how to do the very basic setup, which allow for using
@code{M-x el-get-install} and friends, then how to get a more involved
setup.

@menu
* Basic Setup::
* The el-get function::
* Distributed Setup::
* Setup Customization::
@end menu

@node Basic Setup
@section Basic Setup

You can then arrange to have El-Get part of your setup, so that at
next emacs startup the installed packages are initialized.

@example
(add-to-list 'load-path "~/.emacs.d/el-get/el-get")

(unless (require 'el-get nil t)
  (with-current-buffer
      (url-retrieve-synchronously
       "https://raw.github.com/dimitri/el-get/master/el-get-install.el")
    (goto-char (point-max))
    (eval-print-last-sexp)))

(el-get 'sync)
@end example

The @code{el-get} command will check that each and every package is
installed on your system (in @code{el-get-dir} and if that's not the
case, it will actually install it. Then, it will init the packages:
that means caring about the @code{load-path}, the
@code{Info-directory-list} (and dir texinfo menu building) the loading
of the emacs-lisp files, and finally it will require the features or
eval the package @code{autoloads}.

This usage is pretty simple to setup and use, but fails to cater with
more complex setups involving multiple deployments (home and work
laptop would be a classic example). El-Get fully supports that
distributed setup, though, and this chapter explain how.

@node The el-get function
@section The el-get function

Ensure that packages have been downloaded once and init them as needed.

This will not update the sources by using @code{apt-get install} or
@command{git pull}, but it will ensure that:

@itemize @bullet

@item the packages have been installed
@item load-path is set so their elisp files can be found
@item Info-directory-list is set so their info files can be found
@item Autoloads have been prepared and evaluated for each package
@item Any post-installation setup (e.g. `(require 'feature)') happens

@end itemize

When @var{sync} is @code{nil} (the default), all installations run
concurrently, in the background.

When @var{sync} is @code{sync}, each package will be installed
synchronously, and any error will stop it all.

Please note that the @code{el-get-init} part of @code{el-get} is
always done synchronously. There's @code{byte-compile} support though,
and the packages you use are welcome to use @code{autoload} too. You
can also force your setup to be loaded lazily with the
@code{el-get-is-lazy} variable.

@code{PACKAGES} is expected to be a list of packages you want to
install or init.  When @code{PACKAGES} is omited (the default), the
list of already installed packages is considered.

@node Distributed Setup
@section Distributed Setup

When you are sharing your emacs setup between several machines (work
and home destops, laptop, etc); it's usual to manage your
@code{.emacs.d} setup in a distributed repository (such as
@code{git}). El-Get then provides an easy canonical list of packages
you depend on to run emacs, and this documentation is usable
as-is.

@example
(add-to-list 'load-path "~/.emacs.d/el-get/el-get")
(require 'el-get)

;; local sources
(setq el-get-sources
 '((:name magit
    :after (global-set-key (kbd "C-x C-z") 'magit-status))

  (:name asciidoc
   :type elpa
   :after (progn
      (autoload 'doc-mode "doc-mode" nil t)
      (add-to-list 'auto-mode-alist '("\\.adoc$" . doc-mode))
      (add-hook 'doc-mode-hook
         '(lambda ()
          (turn-on-auto-fill)
           (require 'asciidoc)))))

  (:name lisppaste :type elpa)

  (:name emacs-goodies-el :type apt-get)))

(setq my-packages
      (append
       '(cssh el-get switch-window vkill google-maps nxhtml xcscope yasnippet)
       (mapcar 'el-get-source-name el-get-sources)))

(el-get 'sync my-packages)
@end example

Please note that when you unreference a package from
@code{my-packages}, it remains locally installed.

Going one step further with the idea of a canonical list, el-get
provides the command @code{el-get-cleanup}, which will remove all
packages absent from @code{my-packages}. This allows, in effect, to
put under version control only the user init file, instead of the
whole @code{.emacs.d} directory, and still enjoy a truly portable
emacs configuration.

In the code example above, replace the last line with the following:

@example
(el-get-cleanup my-packages)
(el-get 'sync my-packages)
@end example 

@node Setup Customization
@section Setup Customization

Even though the defaults that are provided by El-Get provide all that
you need to get it working, there may be a reason to manually define
certain settings, particularly for portability.

@table @code

@item el-get-dir
Path where packages are installed. Defaults to
@file{~/.emacs.d/el-get/}.

@item el-get-install-dir
Path for the @code{el-get} package. Defaults to
@file{~/.emacs.d/el-get/el-get}.

@item el-get-install-branch
If this is set, El-Get will be installed using the target
@code{branch}.  This takes precedence over setting
@code{el-get-master-branch} in the installation settings, see
@xref{Installing}.

@item el-get-git-install-url
Use this to specify your own fork of El-Get for installation.

@item el-get-recipe-path-elpa
This directory stores a local list of ELPA recipes.
@file{~/.emacs.d/el-get/el-get/recipes/elpa}

@item el-get-recipe-path-emacswiki

As above for ELPA, this directory stores a local list of emacswiki
recipes. Defaults to
@file{~/.emacs.d/el-get/el-get/recipes/emacswiki/}.

@end table

@node User Init
@chapter User Init

The main task performed by El-Get is package initialization at Emacs
startup. It will care about all of them, their dependencies, and call
code provided by the recipe author. You can add your own setup code
and register it in a way that El-Get will evaluate it at the right
time.

The package setup can either go into the @code{:after} property, or in
a file named @file{init-package.el} in
@code{el-get-user-package-directory}.  Any such named file will get
automatically loaded by El-Get at package init time, if it exists.

@menu
* Before and After properties ::
* Initialization files::
@end menu

@node Before and After properties
@section Before and After properties

The @code{:before} and @code{:after} properties are evaluated by
El-Get in the package initialization sequence.

@table @code

@item :before
This should be a lisp form to evaluate after both the
@code{Info-directory-list} and the @code{load-path} variables have
been taken care of, but before loading the package or any further
action from @code{el-get-init}.  It will be run with the variable
@code{default-directory} set to the package directory.

@item :after
This should be a lisp form to evaluate after loading the package.
This function is registered for @code{eval-after-load} against the
recipe library by @code{el-get-init} once the @code{:load} and
@code{:features} have been setup. It will be run with the variable
@code{default-directory} set to the package directory.

@end table

Here's a couple of examples of package recipes that are using
@code{:before} and @code{:after} properties:

@example
  (:name asciidoc
   :type elpa
   :after (lambda ()
      (autoload 'doc-mode "doc-mode" nil t)
      (add-to-list 'auto-mode-alist '("\\.adoc$" . doc-mode))
      (add-hook 'doc-mode-hook '(lambda ()
                (turn-on-auto-fill)
                (require 'asciidoc)))))

  (:name anything
   :features anything-config
   :before (global-set-key (kbd "M-s a") 'dim:anything-occur)
   :after  (setq w3m-command nil))
@end example

@node Initialization files
@section Initialization files

El-Get will see if a file named @file{init-package.el} exists in the
directory pointed at by the @code{el-get-user-package-directory}
variable. When this variable is not nil and if such a file does exist
in the directory, then El-Get will load the user init file for
@var{package}.

The initialization file is loaded at the same time as the
@code{:after} property would have be run, and just before it if you
provide both.

El-Get automatically byte compiles the init file as needed and load
the compiled version.

@node Recipes
@chapter Recipes

All of El-Get behavior is controled with recipes that you can share,
download, update and author. This chapter explain how to manage your
recipes and how to author them and ship them.

Recipes are a list of properties, which are documented in the variable
@var{el-get-sources}.

@menu
* Organizing recipes::
* Getting more recipes::
* Overriding package files::
@end menu

@node Organizing recipes
@section Organizing recipes

El-Get needs to find a package recipe to be able to install or update
it. After that the recipe content is saved in the status file and
cached, so that you can still start Emacs even if you remove the
recipe file.

The variable @code{el-get-recipe-path} is a list of directory paths
where to look for recipe files, in order. The recipe for a package
@code{example} must be named @code{example.rcp}. The first file named
that way in the @code{el-get-recipe-path} variable is used as the
recipe.

To check which recipe is used for a given package, use either the
@code{M-x el-get-describe} or @code{M-x el-get-find-recipe-file}
command.

This organisation with several path allow you to setup El-Get to use
its own recipes, recipes automatically created from online resources
(such as Emacswiki), and your own local recipes.

As it's easy for El-Get to use your own recipes in the exact same way
than it uses its own recipes, it allows you to share them very
easily. Send the file to a friend and have it store it at the right
place.

It's also possible to setup @code{el-get-sources} with recipe
information. As long as the @code{type} property is not filled in
@code{el-get-sources}, El-Get will first find the recipe as usual and
then merge the recipe content with the recipe skeleton provided by the
matching @code{el-get-sources} stanza.

El-Get also supports full User Init files, see @xref{User Init}.

@node Getting more recipes
@section Getting more recipes

The command @code{M-x el-get-emacswiki-refresh} downloads the list of
Emacs Lisp files available at EmacsWiki. El-Get is able to
automatically install any such file at the right place in
@code{el-get-dir}. The integration of an automatically generated
recipe is often not enough, you often have to add some initialisation
code. See @xref{User Init}.

The command @code{el-get-elpa-build-local-recipes} downloads the list
of Emacs Lisp Packages from the ELPA archives you have setup, and make
them automatically available for El-Get.

@node Overriding package files
@section Overriding package files

El-Get manages the files associated with a package. You can browse
those files using the @code{el-get-cd} function. It's possible to hack
on those files, be aware that doing so might break your setup
capability to handle upgrades.

@node Authoring Recipes
@chapter Authoring Recipes

Authoring recipes is often very easy. El-Get goal is to adapt to any
Emacs Lisp code and distribution you can find out there in the wild,
so the list of features supported is quite large. Simple cases are
very simple, though.

@menu
* Recipe format::
* Dependencies::
* Byte Compilation::
* Autoloads::
* Build::
@end menu

@node Recipe format
@section Recipe format

The recipe for the hypothetical package named @code{el-get-example}
must be provided in a file named @file{el-get-example.rcp}. This file
will be searched for as described in @xref{Organizing recipes}. The
variable @code{el-get-sources} is also considered as a recipe source,
as detailed in @xref{Organizing recipes}.

A recipe file contains a lisp property list. Accepted properties are
described in the documentation for the variable @code{el-get-sources},
and their possible values are described at the same place.

Please refer to that documentation.

@node Dependencies
@section Dependencies

When a recipe provides a @code{:depends} property, El-Get makes sure
that the given list of packages is installed and initialized before
the package for the current recipe is installed and initialized.

@node Byte Compilation
@section Byte Compilation

By default, El-Get will recursively byte-compile the directory where
the package is installed, that is each and any file called
@file{something.el}. Some packages include non Emacs Lisp directories,
and sometime test files that are not meant to pass byte compilation
without errors or warnings. It is possible to setup your recipe to
either only target some files of the package, or to bypass byte
compiling entirely.

@node Autoloads
@section Autoloads

Think about providing @code{autoloads} for your recipe if some are
available. You can provide them yourself too, for packages that should
have support for autoloads but ship without them.

The @code{:prepare} property of a recipe is the right place where to
put added autoloads, as shown in this example:

@example
(:name undo-tree
       :description "Treat undo history as a tree"
       :type git
       :url "http://www.dr-qubit.org/git/undo-tree.git"
       :prepare (progn
                  (autoload 'undo-tree-mode "undo-tree.el"
                    "Undo tree mode; see undo-tree.el for details" t)
                  (autoload 'global-undo-tree-mode "undo-tree.el"
                    "Global undo tree mode" t)))
@end example

The @code{:prepare} property of a recipe is considered the same as the
@code{:before} one, just evaluated after it. @code{:prepare} is meant
for recipe authors whereas @code{:before} is meant for user
customisations. See @xref{Before and After properties}.

@node Build
@section Build

The @code{:build} property of the recipe allows for OS integration at
build time. Build happens after the package has been fetched, and
allows to run commands such as @command{make}.

The variable @code{el-get-emacs} contains the complete path where to
find the current Emacs executable you're running, as that's something
build commands often need.

As shell interpolation can get hairy, El-Get offers you to setup your
build commands as Emacs Lisp list. See the magit recipe for an
example:

@example
(:name magit
       :website "https://github.com/magit/magit#readme"
       :description "It's Magit! An Emacs mode for Git."
       :type github
       :pkgname "magit/magit"
       :info "."
       :autoloads ("50magit")
       :build (("make" "all"))
       :build/darwin `(,(concat "make EMACS=" el-get-emacs " all")))
@end example

@bye