This implements removing of the shims path element via bash
substitution, instead of jumping around in all the `$PATH` elements.

Running any shim (and thus `rbenv-exec`) would always execute
`rbenv-version-name` twice: once in `rbenv-exec` and another time in
`rbenv-which`, even though RBENV_VERSION variable would have already
been populated at this point.

Now RBENV_VERSION is respected within `rbenv-which`.

Fixes #626

The previous Makefile only worked on OS X. The dynamically generated
Makefile (from `Makefile.in`) should now work on multiple platforms
(tested on OS X and Ubuntu).

The `shobj-conf` script imported from bash seems to not support the
latest OS X. This makes sure that `SHOBJ_LDFLAG=-dynamiclib` is output
for Darwin10+ (latest version is Darwin 13.0).

Given the `-o <HOST-OS>` parameter, the script generates environment
variables with information how to compile dynamically loadable libraries
for that system.

Imported from bash-3.2.48

Seems to only work on OS X; fails on Travis
https://travis-ci.org/sstephenson/rbenv/jobs/16384866

It's slow and not necessary since we expect `$0` to already be expanded.

In tests this change forces us to deal with some relative paths, but
it's not a big deal. The `rbenv init -` output in the most common case
will be the same as before:

    source '/home/myuser/.rbenv/libexec/../completions/rbenv.bash'

This speeds up every `rbenv` invocation significantly.

With `realpath` extension, hooks tests on OS X will output
`/private/tmp` instead of `/tmp` because the latter is an actual symlink
to the former.

Avoid this mistmach in output assertions by expanding BATS_TMPDIR if
`realpath` extension is compiled.

On systems that support both C compiling and dynamic loading, we can
speed up `realpath()` (where most time in rbenv is spent) by replacing
it with a dynamically loaded bash builtin.

When `make -C src` is called in the project's root,
`libexec/rbenv-realpath.dylib` will be created. If it exists, rbenv will
attempt to load it as a builtin command. If it fails, execution will
fall back to the old `realpath()` shell function.

Allows for code to be added to the end of the script which will not
mysteriously fail to run for fish shell.

Prefer gawk over awk if both are available.

Fixes rbenv-help on Solaris 11.1

Remove carriage return characters in version file

Fixes #566

When created on Windows, .rbenv-version or .ruby-version files may have CR characters that will prevent rbenv from correctly parsing the Ruby version. Discard those characters when reading the file.

This prevents the tests from removing an existing directory.

Fixes #561 (https://github.com/sstephenson/rbenv/issues/561)

finding_local_version_file is extremely slow, when working directory is under the UNC path.
Because //host/.rbenv-version and //.rbenv-version do not exist, but testing them is so slow.
It's the reason to make a serious delay of the response, when the Ruby runs with a current working directory under the UNC path under Cygwin environment.

A response of before applying this patch.
//somehost/somedir $ time ruby -e "exit"

real    0m13.922s
user    0m0.168s
sys     0m0.287s

A response of after applying this patch.
//somehost/somedir $ time ruby -e "exit"

real    0m0.721s
user    0m0.153s
sys     0m0.319s

Closes #524

It seems that "comm" header can't be relied on cross-platform, but that
"ucomm" is more portable. I have no idea whether it's the right value to
use here, but it seems to be doing the job.

Also strip trailing whitespace because OpenBSD 5.4 `ps` output is padded
with spaces for some reason.

Fixes #489

The non-extended regex pattern didn't work on OpenBSD so this switches
grep to extended pattern mode that seems to work consistenty on all
systems.

On other systems, we expected to find system Ruby in `/usr/bin`, but in
OpenBSD 5.4 it will be found in `/usr/local/bin`.

This replaces the limited USRBIN_ALT hack with a more generic
`path_without` function that will ensure that the given executable is
not present in the resulting PATH even if it's found in multiple
system paths.

The error was "bash: no such file or directory" and it was due to bash
being located in `/usr/local/bin` on OpenBSD 5.4 instead of `/bin` like
on other systems.

Fixed by keeping `/usr/local/bin` in PATH during the test run.

Fix rbenv on OpenBSD

Fixes #519

In Travis CI environment, Bats thinks it's outputting to an interactive
terminal, so it switches to "pretty" format and ANSI escape codes which
don't look well in the final output.

Some tests assumed that the `ruby` executable will be found in system PATH.

Fixes #512, closes #514

ignore cache directory used by ruby-build

Remove Neckbeard reference in favor of Advanced

Fish user config file `~/.config/fish/config.fish` loads for every
instance of fish shell, not just interactive ones. Since it's
unnecessary and dangerous to eval `rbenv init -` output in
non-interactive shells, wrap the invocation in a conditional that checks
if the current shell is interactive.

Fixes #501

It was supposed to fix shelling out to Ruby but it in fact broke another
kind of shelling out to Ruby: invoking the `ruby` binary directly with
the `-S` flag.

Fixes #480

This reverts commit db143bb654.

It doesn't exist as a builtin, and it doesn't seem there is a way to
detect support for a shell builtin that is portable. So, just detect
fish and don't the rehash command at all.

Fixes #478

Change `exec` semantics to allow using rbenv from a ruby process

Process substitution seems to be causing problems with some versions of
bash on specific systems.

Fixes #401

Avoids the case where shell detection would result in
`basename "-bash"` invocation, triggering the error:

    basename: illegal option -- b

fixes #462