@title Arcanist User Guide
@group userguide

Guide to Arcanist, a command-line interface to Phabricator.

Arcanists provides command-line access to many Phabricator tools (like
Differential, Files, and Paste), integrates with static analysis ("lint") and
unit tests, and manages common workflows like getting changes into Differential
for review.

A detailed command reference is available by running ##arc help##. This
document provides a high level overview of common workflows.

Arcanist has technical, contributor-focused documentation here:
<http://www.phabricator.com/docs/arcanist/>

= Overview =

Arcanist is a wrapper script that sits on top of other tools (e.g.,
Differential, linters, unit test frameworks, git, Mercurial, and SVN) and
provides a simple command-line API to manage code review and some related
revision control operations.

Arcanist allows you to do things like:

  - get detailed help about available commands with ##arc help##
  - send your code to Differential for review with ##arc diff##
  - show pending revision information with ##arc list##
  - find likely reviewers for a change with ##arc cover##
  - apply changes in a revision to the working copy with ##arc patch##
  - download a patch from Differential with ##arc export##
  - update Git commit messages after review with ##arc amend##
  - commit SVN changes with ##arc commit##
  - push Git changes with ##arc land##
  - view enhanced information about Git branches with ##arc branch##

Once you've configured lint and unit test integration, you can also:

  - check your code for syntax and style errors with ##arc lint##
  - run unit tests that cover your changes with ##arc unit##

Arcanist integrates with other tools:

  - upload and download files with ##arc upload## and ##arc download##
  - create and view pastes with ##arc paste##

Arcanist has some advanced features as well, you can:

  - execute Conduit method calls with ##arc call-conduit##
  - create or update libphutil libraries with ##arc liberate##
  - activate tab completion with ##arc shell-complete##
  - install arc as a pre-commit hook with ##arc svn-hook-pre-commit## or
    ##arc git-hook-pre-receive##
  - ...or extend Arcanist and add new commands.

Except where otherwise noted, these workflows are generally agnostic to the
underlying version control system and will work properly in git, Mercurial, or
SVN repositories.

= Installing Arcanist =

Arcanist is meant to be installed on your local machine or development server --
whatever machine you're editing code on. It runs on Linux, Mac OS X, and
Windows (see @{article:Arcanist User Guide: Windows}).

Arcanist is written in PHP, so you need to install the PHP CLI first if you
don't already have it. Arcanist should run on PHP 5.2 and newer. If you don't
have PHP installed, you can download it from <http://www.php.net/>.

To install Arcanist, pick an install directory and clone the code from GitHub:

  some_install_path/ $ git clone git://github.com/facebook/libphutil.git
  some_install_path/ $ git clone git://github.com/facebook/arcanist.git

This should leave you with a directory structure like this

  some_install_path/    # Wherever you chose to install it.
    arcanist/           # Arcanist-specific code and libraries.
    libphutil/          # A shared library Arcanist depends upon.

Now add ##some_install_path/arcanist/bin/## to your PATH environment variable.
When you type "arc", you should see something like this:

  Usage Exception: No command provided. Try 'arc help'.

If you get that far, you've done things correctly. If you get an error or have
trouble getting this far, see these detailed guides:

  - On Windows: @{article:Arcanist User Guide: Windows}
  - On Mac OS X: @{article:Arcanist User Guide: Mac OS X}

You can later upgrade Arcanist and libphutil to the latest versions with
`arc upgrade`:

  $ arc upgrade

== Installing Arcanist for a Team ==

Arcanist changes quickly and doesn't currently have an auto-update mechanism,
so it can be something of a headache to get it installed and keep people up to
date. Here are some approaches you might be able to use:

  - Facebook does most development on development servers, which have a standard
    environment and NFS mounts. Arcanist and libphutil themselves live on an
    NFS mount, and the default `.bashrc` adds them to the PATH. Updating the
    mount source updates everyone's versions, and new employees have a working
    `arc` when they first log in.
  - Another common approach is to write an install script as an action into
    existing build scripts, so users can run `make install-arc` or
    `ant install-arc` or similar.
  - In general, if this sucks and is causing you pain, let us know (see
    @{article:Give Feedback! Get Support!}). We're planning to improve this at
    some point, but it's somewhat complicated to get right. While it can take a
    little time to set up, we aren't getting feedback that it's a persistent
    pain point, so it hasn't been a priority.

== Installing Tab Completion ==

If you use ##bash##, you can set up tab completion by adding something like this
to your ##.bashrc##, ##.profile## or similar:

  source /path/to/arcanist/resources/shell/bash-completion

== Next Steps ==

Continue by:

  - learning how to use `arc` to send changes for review with
    @{article:Arcanist User Guide: arc diff}.