Simple D Version Management: denv

denv lets you easily switch between multiple versions of D. It's
simple, unobtrusive, and follows the UNIX tradition of single-purpose
tools that do one thing well.

denv is a D version of rbenv. Thanks to @sstephenson.

denv does?

Let you change the global D version on a per-user basis.
Provide support for per-project D versions.
Allow you to override the D version with an environment
variable.

1 How It Works
2 Installation
- 2.1 Basic GitHub Checkout
  - 2.1.1 Upgrading
- 2.2 Neckbeard Configuration
3 Usage
4 Development
- 4.1 Version History
- 4.2 License

1 How It Works

denv operates on the per-user directory ~/.denv. Version names in
denv correspond to subdirectories of ~/.denv/versions. For
example, you might have ~/.denv/versions/dmd-1.071 and
~/.denv/versions/dmd-2.059.

Each version is a working tree with its own binaries, like
~/.denv/versions/dmd-1.071/bin/dmd and
~/.denv/versions/dmd-2.059/bin/rdmd. denv makes shim binaries
for every such binary across all installed versions of D.

These shims are simple wrapper scripts that live in ~/.denv/shims
and detect which D version you want to use. They insert the
directory for the selected version at the beginning of your $PATH
and then execute the corresponding binary.

Because of the simplicity of the shim approach, all you need to use
denv is ~/.denv/shims in your $PATH.

2 Installation

Compatibility note: denv is incompatible with dvm.

2.1 Basic GitHub Checkout

This will get you going with the latest version of denv and make it
easy to fork and contribute any changes back upstream.

Check out denv into ~/.denv.

 $ cd
 $ git clone git://github.com/repeatedly/denv.git .denv

Add ~/.denv/bin to your $PATH for access to the denv
command-line utility.
```
 $ echo 'export PATH="$HOME/.denv/bin:$PATH"' >> ~/.bash_profile
```
Zsh note: Modify your ~/.zshenv file instead of ~/.bash_profile.
Add denv init to your shell to enable shims and autocompletion.
```
 $ echo 'eval "$(denv init -)"' >> ~/.bash_profile
```
Zsh note: Modify your ~/.zshenv file instead of ~/.bash_profile.
Restart your shell so the path changes take effect. You can now
begin using denv.
```
 $ exec $SHELL
```
Install D versions by using denv install.
```
 $ denv install dmd-2.059
```

2.1.1 Upgrading

If you've installed denv using the instructions above, you can
upgrade your installation at any time using git.

To upgrade to the latest development version of denv, use git pull:

$ cd ~/.denv
$ git pull

To upgrade to a specific release of denv, check out the corresponding
tag:

$ cd ~/.denv
$ git fetch
$ git tag
v0.1.0
v0.1.1
v0.1.2
v0.2.0
$ git checkout v0.2.0

2.2 Neckbeard Configuration

Skip this section unless you must know what every line in your shell
profile is doing.

denv init is the only command that crosses the line of loading
extra commands into your shell. Coming from rvm, some of you might be
opposed to this idea. Here's what denv init actually does:

Sets up your shims path. This is the only requirement for denv to
function properly. You can do this by hand by prepending
~/.denv/shims to your $PATH.
Installs autocompletion. This is entirely optional but pretty
useful. Sourcing ~/.denv/completions/denv.bash will set that
up. There is also a ~/.denv/completions/denv.zsh for Zsh
users.
Rehashes shims. From time to time you'll need to rebuild your
shim files. Doing this on init makes sure everything is up to
date. You can always run denv rehash manually.
Installs the sh dispatcher. This bit is also optional, but allows
denv and plugins to change variables in your current shell, making
commands like denv shell possible. The sh dispatcher doesn't do
anything crazy like override cd or hack your shell prompt, but if
for some reason you need denv to be a real script rather than a
shell function, you can safely skip it.

Run denv init - for yourself to see exactly what happens under the
hood.

3 Usage

Like git, the denv command delegates to subcommands based on its
first argument. The most common subcommands are:

3.1 denv global

Sets the global version of D to be used in all shells by writing
the version name to the ~/.denv/version file. This version can be
overridden by a per-project .denv-version file, or by setting the
DENV_VERSION environment variable.

$ denv global dmd-2.059

The special version name system tells denv to use the system D
(detected by searching your $PATH).

When run without a version number, denv global reports the
currently configured global version.

3.2 denv local

Sets a local per-project D version by writing the version name to
an .denv-version file in the current directory. This version
overrides the global, and can be overridden itself by setting the
DENV_VERSION environment variable or with the denv shell
command.

$ denv local dmd-2.058

When run without a version number, denv local reports the currently
configured local version. You can also unset the local version:

$ denv local --unset

3.3 denv shell

Sets a shell-specific D version by setting the DENV_VERSION
environment variable in your shell. This version overrides both
project-specific versions and the global version.

$ denv shell dmd-2.059

When run without a version number, denv shell reports the current
value of DENV_VERSION. You can also unset the shell version:

$ denv shell --unset

Note that you'll need denv's shell integration enabled (step 3 of
the installation instructions) in order to use this command. If you
prefer not to use shell integration, you may simply set the
DENV_VERSION variable yourself:

$ export DENV_VERSION=dmd-2.058

3.4 denv versions

Lists all D versions known to denv, and shows an asterisk next to
the currently active version.

$ denv versions
  dmd-2.058
* dmd-2.059 (set by /Users/sam/.denv/global)
  gdc-2.x
  ldc-x.x

NOTE: Now, gdc is not supported.

3.5 denv version

Displays the currently active D version, along with information on
how it was set.

$ denv version
dmd-2.059 (set by /Volumes/37signals/basecamp/.denv-version)

3.6 denv rehash

Installs shims for all D binaries known to denv (i.e.,
~/.denv/versions/*/os/bin/*). Run this command after you install a new
version of D, or install a gem that provides binaries.

$ denv rehash

3.7 denv which

Displays the full path to the binary that denv will execute when you
run the given command.

$ denv which dmd
/Users/sam/.denv/versions/dmd-2.059/osx/bin/dmd

3.8 denv install

Install a D version.

$ denv install dmd-2.061
Downloading 2.061...
2013-01-20 18:02:24 URL:http://downloads.dlang.org.s3-website-us-east-1.amazonaws.com/releases/2013/dmd.2.061.zip [31601020/31601020] -> "-" [1]
Installing 2.061 to /Users/sam/.denv/versions/dmd-2.061

Currenlty, support compiliers are dmd and ldc. gdc will be added.

3.9 denv uninstall

Uninstall a specific D version.

$ denv uninstall dmd-2.061
denv: remove /Users/sam/.denv/versions/dmd-2.061? y

4 Development

The denv source code is hosted on
GitHub. It's clean, modular,
and easy to understand, even if you're not a shell hacker.

Please feel free to submit pull requests and file bugs on the issue
tracker.

4.1 Version History

0.1.2 (January 22, 2013)

Add install and uninstall.

0.1.1 (March 5, 2012)

Fix Linux environemnt bug.

0.1.0 (March 4, 2012)

Fork rbenv

4.2 License

(The MIT license)

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

repeatedly/denv