tips-n-tricks: misc. edits

share/doc/homebrew/Tips-N'-Tricks.md

@@ -1,20 +1,25 @@
 # 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 previous versions of formulae
+
+The preferred and supported method of installing specific versions of
+formulae is to use the
+[Homebrew-versions](https://github.com/Homebrew/homebrew-versions)
+tap.  If the version you’re looking for isn’t available, consider [opening a
+pull request](https://github.com/Homebrew/homebrew/blob/master/share/doc/homebrew/How-To-Open-a-Homebrew-Pull-Request-(and-get-it-merged).md)!
 
 ### 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
+```sh
 brew install https://raw.github.com/dsr/homebrew/9b22d42f50fcbc5e52c764448b3ac002bc153bd7/Library/Formula/python3.rb
 ```
 
 ## Quickly remove something from /usr/local
 
-```bash
+```sh
 brew unlink $FORMULA
 ```
 
@@ -22,19 +27,14 @@ This can be useful if a package can't build against the version of something you
 
 And of course, you can simply `brew link $FORMULA` again afterwards!
 
-
-
 ## Install into Homebrew without formulas
 
-```bash
+```sh
 ./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):
 
@@ -42,7 +42,6 @@ Add to your `~/.bashrc` or `~/.bash_profile` (whichever you have configured to r
 source $(brew --repository)/Library/Contributions/brew_bash_completion.sh
 ```
 
-
 ### Zsh
 Run in terminal (may require `sudo`):
 
@@ -52,32 +51,39 @@ ln -s "$(brew --prefix)/Library/Contributions/brew_zsh_completion.zsh" /usr/loca
 
 ## 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>.
+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.
 
-**New:**
+Download the file and drop it in `~/Library/Caches/Homebrew`, but
-```bash
+watch the file name.  Homebrew downloads files as <code>{{ formula
-mv the_tarball `brew --cache formula-name`
+name }}-{{ version }}</code>.  In the case of Erlang, this requires
-```
+renaming the file from <code>otp_src_R13B03</code> to
+<code>erlang-R13B03</code>.
+
+`brew –-cache -s erlang` will print the correct name of the cached
+download.  This means instead of manually renaming a formula, you can
+run `mv the_tarball $(brew --cache -s $FORMULA)`.
 
 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:
+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), including at runtime:
 
-```bash
-$ http_proxy=http://<proxyhost>:<proxyport>  brew install $FORMULA
 ```
-
+http_proxy=http://<proxyhost>:<proxyport> brew install $FORMULA
+```
 
 ### Proxy Authentication
 
-```bash
+```sh
-$ http_proxy=http://<user>:<password>@<proxyhost>:<proxyport>  brew install $FORMULA
+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.
@@ -90,7 +96,7 @@ $ http_proxy=http://<proxyhost>:<proxyport>  sudo -E brew install $FORMULA
 
 ## Installing stuff without the Xcode-CLT
 
-```bash
+```sh
 $ brew sh          # or: eval $(brew --env)
 $ gem install ronn # or c-programs
 ```
@@ -99,13 +105,13 @@ This imports the brew environment into your existing shell, gem will pick up the
 
 ## Install only a formula's dependencies (not the formula)
 
-```
+```sh
 brew install --only-dependencies $FORMULA
 ```
 
-## brew irb
+## Interactive Homebrew Shell
 
-```bash
+```sh
 $ 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]
@@ -114,7 +120,7 @@ $ brew irb
 
 ## Hiding the beer mug emoji when finishing a build
 
-```bash
+```sh
 export HOMEBREW_NO_EMOJI=1
 ```
 
@@ -123,7 +129,7 @@ to hide all emoji.
 
 The beer emoji can also be replaced with other character(s):
 
-```bash
+```sh
 export HOMEBREW_INSTALL_BADGE="☕️ 🐸"
 ```