# Tips N' Tricks
## Package versions

The preferred and supported method of installing specific versions of formulae is to use the [Homebrew-versions](https://github.com/Homebrew/homebrew-versions) tap.

### Installing directly from pull-requests

You can browse pull requests https://github.com/Homebrew/homebrew/pulls
and install through the direct link. For example Python 3.3.0 pull request https://github.com/Homebrew/homebrew/pull/15199

```zsh
brew install https://raw.github.com/dsr/homebrew/9b22d42f50fcbc5e52c764448b3ac002bc153bd7/Library/Formula/python3.rb
```

## Quickly remove something from /usr/local

```bash
brew unlink $FORMULA
```

This can be useful if a package can't build against the version of something you have linked into `/usr/local`.

And of course, you can simply `brew link $FORMULA` again afterwards!



## Install into Homebrew without formulas

```bash
./configure --prefix=/usr/local/Cellar/foo/1.2 && make && make install && brew link foo
```



## Command tab-completion


### Bash
Add to your `~/.bashrc` or `~/.bash_profile` (whichever you have configured to run on shell startup):

```bash
source `brew --repository`/Library/Contributions/brew_bash_completion.sh
```


### ZSH
Run in terminal (may require `sudo`):

```zsh
ln -s "$(brew --prefix)/Library/Contributions/brew_zsh_completion.zsh" /usr/local/share/zsh/site-functions
```

## Pre-downloading a file for a formula

Sometimes it's faster to download a file via means other than those strategies that are available as part of Homebrew.  For example, Erlang provides a Torrent that'll let you download at 4–5× the normal HTTP method.  Download the file and drop it in `~/Library/Caches/Homebrew`, but watch the file name.  Homebrew downloads files as <code>{{ formula name }}-{{ version }}</code>.  In the case of Erlang, this requires renaming the file from <code>otp_src_R13B03</code> to <code>erlang-R13B03</code>.

**New:**
```bash
mv the_tarball `brew --cache formula-name`
```

You can also pre-cache the download by using the command `brew fetch formula` which also displays the SHA1 and SHA256 values. This can be useful for updating formulae to new versions.



## Using Homebrew behind a proxy

Behind the scenes, Homebrew uses several commands for downloading files (e.g. curl, git, svn).  Many of these tools can download via a proxy.  It's a common (though not universal) convention for these command-line tools to observe getting the proxy parameters from environment variables (e.g. `http_proxy`).  Unfortunately, most tools are inconsistent in their use of these environment parameters (e.g. curl supports `http_proxy`, `HTTPS_PROXY`, `FTP_PROXY`, `GOPHER_PROXY`, `ALL_PROXY`, `NO_PROXY`).

Luckily, for the majority of cases setting `http_proxy` is enough.  You can set this environment variable in several ways (search on the internet for details), but the way I prefer is:

```bash
$ http_proxy=http://<proxyhost>:<proxyport>  brew install $FORMULA
```


### Proxy Authentication

```bash
$ http_proxy=http://<user>:<password>@<proxyhost>:<proxyport>  brew install $FORMULA
```

**NB:** this technique will also work if you prefer to use `sudo` with Homebrew.  But as `sudo` clears the environment before executing Homebrew, your proxy settings may get lost.

**Workaround:**

```bash
$ http_proxy=http://<proxyhost>:<proxyport>  sudo -E brew install $FORMULA
```

## Installing stuff without the Xcode-CLT

```bash
$ brew sh          # or: eval $(brew --env)
$ gem install ronn # or c-programs
```

This imports the brew environment into your existing shell, gem will pick up the environment variables and be able to build. As a bonus brew's automatically determined optimization flags are set.

## Install only a formula's dependencies (not the formula)

```
brew install --only-dependencies $FORMULA
```

## brew irb

```bash
$ brew irb
1.8.7 :001 > Formula.factory("ace").methods - Object.methods
 => [:install, :path, :homepage, :downloader, :stable, :bottle, :devel, :head, :active_spec, :buildpath, :ensure_specs_set, :url, :version, :specs, :mirrors, :installed?, :explicitly_requested?, :linked_keg, :installed_prefix, :prefix, :rack, :bin, :doc, :include, :info, :lib, :libexec, :man, :man1, :man2, :man3, :man4, :man5, :man6, :man7, :man8, :sbin, :share, :etc, :var, :plist_name, :plist_path, :download_strategy, :cached_download, :caveats, :options, :patches, :keg_only?, :fails_with?, :skip_clean?, :brew, :std_cmake_args, :deps, :external_deps, :recursive_deps, :system, :fetch, :verify_download_integrity, :fails_with_llvm, :fails_with_llvm?, :std_cmake_parameters, :mkdir, :mktemp]
1.8.7 :002 >
```

## Hiding the beer mug emoji when finishing a build

```bash
export HOMEBREW_NO_EMOJI=1
```

This sets the HOMEBREW_NO_EMOJI environment variable, causing homebrew to hide all emoji.

## Sublime text: Syntax for formulae including the diff

In Sublime Text 2/3, you can use Package Control to install [Homebrew-formula-syntax](https://github.com/samueljohn/Homebrew-formula-syntax).