# Gox - Simple Go Cross Compilation

Gox is a simple, no-frills tool for Go cross compilation that behaves a
lot like standard `go build`. Gox will parallelize builds for multiple
platforms. Gox will also build the cross-compilation toolchain for you.

## Installation

To install Gox, please use `go get`. We tag versions so feel free to
checkout that tag and compile.

```
$ go get github.com/mitchellh/gox
...
$ gox -h
...
```

## Usage

Before you use Gox, you must build the cross-compilation toolchain. Gox can
do this for you and will parallelize this process. Still, it can take some
time. This only has to be done once (or whenever you update Go):

```
$ gox -build-toolchain
...
```

Once that is done, you're ready to cross compile!

If you know how to use `go build`, then you know how to use Gox. For
example, to build the current package, specify no parameters and just
call `gox`. Gox will parallelize based on the number of CPUs you have
by default and build for every platform by default:

```
$ gox
Number of parallel builds: 4

-->      darwin/386: github.com/mitchellh/gox
-->    darwin/amd64: github.com/mitchellh/gox
-->       linux/386: github.com/mitchellh/gox
-->     linux/amd64: github.com/mitchellh/gox
-->       linux/arm: github.com/mitchellh/gox
-->     freebsd/386: github.com/mitchellh/gox
-->   freebsd/amd64: github.com/mitchellh/gox
-->     openbsd/386: github.com/mitchellh/gox
-->   openbsd/amd64: github.com/mitchellh/gox
-->     windows/386: github.com/mitchellh/gox
-->   windows/amd64: github.com/mitchellh/gox
-->     freebsd/arm: github.com/mitchellh/gox
-->      netbsd/386: github.com/mitchellh/gox
-->    netbsd/amd64: github.com/mitchellh/gox
-->      netbsd/arm: github.com/mitchellh/gox
-->       plan9/386: github.com/mitchellh/gox
```

Or, if you want to build a package and sub-packages:

```
$ gox ./...
...
```

Or, if you want to build multiple distinct packages:

```
$ gox github.com/mitchellh/gox github.com/hashicorp/serf
...
```

Or if you want to just build for linux:

```
$ gox -os="linux"
...
```

Or maybe you just want to build for 64-bit linux:

```
$ gox -osarch="linux/amd64"
...
```

And more! Just run `gox -h` for help and additional information.

## Versus Other Cross-Compile Tools

A big thanks to these other options for existing. They each paved the
way in many aspects to make Go cross-compilation approachable.

* [Dave Cheney's golang-crosscompile](https://github.com/davecheney/golang-crosscompile) -
  Gox compiles for multiple platforms and can therefore easily run on
  any platform Go supports. Dave's scripts require a shell.

* [goxc](https://github.com/laher/goxc) -
  A very richly featured tool that can even do things such as build system
  packages, upload binaries, generate download webpages, etc. Gox is a
  super slim alternative that only cross-compiles binaries. goxc assumes that
  you're cross-compiling using the same version of Go that built goxc, whereas
  Gox can be used anywhere a `go` binary is available. So you can build Gox
  with Go 1.2 and build with Go 1.0.

