Split monolithic method into more manageable chunks and fix code style.

Since edf000e4 `zsh` completions are in
`share/zsh/site-functions/_brew`, making this path a part of Homebrew.
Hide it from `brew list --unbrewed` to reduce confusion/noise.

Fixes #70.

Signed-off-by: Baptiste Fontaine <batifon@yahoo.fr>

Currently, brew audit --strict includes the name of the tap when calculating the
length of a formula's description. This makes it difficult to pass the audit for
formulas in taps with lengthy names. In #47033 @jawshooah called out head-only
or devel-only taps specifically, but this is an issue elsewhere. For example:

homebrew/versions/elasticsearch20: Distributed search & analytics engine (72)

This commit updates audit.rb to use formula.name rather than formula.full_name.

Closes #47033 -- Audit shouldn't include tap name in description length

Closes #92.

Signed-off-by: Xu Cheng <xucheng@me.com>

Also add options to include optional/build deps and an option
to skip recommended deps.

Closes Homebrew/legacy-homebrew#50066.

By the commit edf000e4, bash and zsh
completion scripts have been moved to `etc/bash_completion.d/brew` and
`share/zsh/site-functions/_brew`, respectively. Now completion will be
done automatically without any trick.

(#85)

Old logic doesn't include revision. This fixes that, and passes the
whole formula prefix path to avoid duplicating the path-construction
logic.

Closes #80.

Signed-off-by: Andrew Janke <andrew@apjanke.net>

Fixes build error in Homebrew/homebrew-core#100.

Closes #63.

Signed-off-by: Andrew Janke <andrew@apjanke.net>

* make `read_or_set_private_config` private
* add doc
* add test

This is coming out of preview shortly so use the new API content-type.

- add `HOMEBREW_PRODUCT` global variable
- only differentiate between `/usr/local` and `non-/usr/local` Homebrew
  prefixes to avoid sharing sensitive user information
- note if e.g. build errors are occurring under CI
- Add `HOMEBREW_NO_ANALYTICS` variable (this will be how people opt-out
  when this is enabled for everyone)
- Add `HOMEBREW_ANALYTICS_DEBUG` variable to output all the analytics
  that are sent
- Move Bash analytics code to `Library/Homebrew/utils/analytics.sh`
- Add documentation for our analytics and why/what/when/how and opt-out
- Only official Homebrew commands are reported
- Ruby analytics are now reported in a forked, background process

We have Jenkins to test the other versions.

Use both an in-class and a `.git/config` cache for this so we can ensure
that the `Tap#private?` check is fast. Also, make sure this cache value
is set both when initially installing and updating a tap.

Thanks to @xu-cheng for most of the implementation here.

Closes #68.

Signed-off-by: Xu Cheng <xucheng@me.com>

Before this fix
```
$ brew --help ls
Error: Unknown command: ls
```

After this fix
```
$ brew --help ls
brew list, ls
<snip>
```

Closes #71.

Signed-off-by: Andrew Janke <andrew@apjanke.net>

Also, slightly tweak the behavior of `brew update` in this case so that
it doesn't print annoying output and still allows the `brew edit` flow
for people with `HOMEBREW_DEVELOPER` set.

Don't exit with a non-zero status code just because an internal command
happens to be undocumented. Also print the generic help in these cases
to provide some help (including a reference to the man page).

Closes #10.

Signed-off-by: Martin Afanasjew <martin@afanasjew.de>

This is also used by `brew <cmd> --help`. The basic idea is to have the
documentation as a top level comment in each command file. To find these
comments, they have to be like this `#:`.

This is also used by the `brew man` command to keep the documentation
DRY, and for that there are now a header and footer for the man page.

xcode: expect 7.3 on 10.11

This is pathological and something that should be fixed in core, not by
working around it.

Closes https://github.com/Homebrew/legacy-homebrew/pull/45704.

Fix style of previously omitted `check_for_bad_install_name_tool`
method to be in line with changes made in #49.

Closes #56.

Signed-off-by: Martin Afanasjew <martin@afanasjew.de>

This reverts commit 9f79c056.

Restore check to continue to inspect `/usr/bin/install_name_tool`. See
Homebrew/legacy-homebrew#50091 and Homebrew/legacy-homebrew#50509 for
the full context and more details.

Guard clauses instead of if/unless blocks make the checks easier to
understand and reduce nesting, thus improving overall readability.

This includes the following additional minor changes:

- Make indentation of commands consistent inside diagnostic messages.
- Fix minor typos and inconsistent punctuation in diagnostic messages.
- Fix here documents to always start with `<<-EOS.undent` on a new line,
  followed by the message (indented once), followed by `EOS` (at the
  same level like `<<-EOS.undent`).
- Always separate the check logic (and guard clauses) from the following
  message by a single empty line (for consistency and readability).
- Standardize on `message` as the variable name when diagnostic messages
  need to be constructed from multiple parts.
- Where easily possible, adapt check logic to stay within 80-column
  limit, use more expressive variable names, and break down long
  expressions into multiple statements with intermediate results.

Closes #49.

Signed-off-by: Martin Afanasjew <martin@afanasjew.de>

This should prevent issues like #47 and make us more resilient.

Using `git` from `Formula#install` can cause an exec bomb if used in a
formula with `env :userpaths` because that causes both `Library/ENV/4.3`
and `Library/ENV/scm` to be in PATH, both of which contain a `git`
binary that is the same SCM wrapper. Those will mutually exec each other
indefinitely as they fail to detect that they are the same wrapper.

Extend the exec-bomb protection to check the paths after all symbolic
links have been expanded to prevent this situation.

Fixes #43.
Fixes Homebrew/homebrew-core#133.
Fixed Homebrew/homebrew-core#143.

Closes #46.

Signed-off-by: Martin Afanasjew <martin@afanasjew.de>

This can happen when `HOMEBREW_CURL` is set to brewed curl, but during

`brew resinstall curl`, brewed curl's symlink is temporary

unlinked.



So let's fallback to /usr/bin/curl in this case.

`uname -p` seems to be less useful on Linux (Debian 8 yields `unknown`),
thus prefer `uname -m` on those systems to determine the processor type.

Closes #35.

Signed-off-by: Martin Afanasjew <martin@afanasjew.de>

On Linux (and other non-OS X platforms), `HOMEBREW_OS_VERSION` was
*always* replaced with the product name, leading to less useful user
agent. E.g., on a reasonably up-to-date Debian system:
  Linuxbrew/0.9.9 (Linux; unknown Linuxbrew)

With this fix the user agent is instead (first if `lsb_release` is
available and outputs something, second otherwise):
  Linuxbrew/0.9.9 (Linux; unknown Debian GNU/Linux 8.3 (jessie))
  Linuxbrew/0.9.9 (Linux; unknown 3.16.0-4-amd64)