site/blog/getting-started-with-go-2015-01-28.markdown

Getting Started with Go

Go is an exciting language made by Google for systems programming. This article will help you get up and running with the Go compiler tools.

System Setup

First you need to install the compilers.

$ sudo apt-get install golang golang-go.tools

golang-go.tools contains some useful tools that aren't part of the standard Go distribution.

Shell Setup

Create a folder in your home directory for your Go code to live in. I use ~/go.

$ mkdir -p ~/go/{bin,pkg,src}

bin contains go binaries that are created from go get or go install. pkg contains static (.a) compiled versions of go packages that are not go programs. src contains go source code.

After you create this, add this and the following to your zsh config:

export GOPATH=$HOME/go
export PATH=$PATH:/usr/lib/go/bin:$GOPATH/bin

This will add the go compilers to your $PATH as well as programs you install.

Rehash your shell config (I use a resource command for this) and then run:

$ go env
GOARCH="amd64"
GOBIN=""
GOCHAR="6"
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/xena/go"
GORACE=""
GOROOT="/usr/lib/go"
GOTOOLDIR="/usr/lib/go/pkg/tool/linux_amd64"
TERM="dumb"
CC="gcc"
GOGCCFLAGS="-g -O2 -fPIC -m64 -pthread"
CXX="g++"
CGO_ENABLED="1"

This will verify that the go toolchain knows where the go compilers are as well as where your $GOPATH is.

Testing

To test the go compilers with a simple todo command, run this:

$ go get github.com/mattn/todo
$ todo add foo
$ todo list
☐ 001: foo

Vim Setup

For Vim integration, I suggest using the vim-go plugin. This plugin used to be part of the standard Go distribution.

To install:

1. Add Plugin 'fatih/vim-go' to the plugins part of your vimrc.
2. Run these commands:

$ vim +PluginInstall +qall
$ vim +GoInstallBinaries +qall

This will install the go oracle and the go autocompletion daemon gocode as well as some other useful tools that will integrate seamlessly into vim. This will also run gofmt on save to style your code to the standard way to write Go code.

Resources

Effective Go and the language spec provide a nice overview of the syntax.

The Go blog contains a lot of detailed articles covering advanced and simple Go topics. This page has a list of past articles that you may find useful.

The Go standard library is a fantastic collection of Go code for solving many problems. In some cases you can even write entire programs using only the standard library. This includes things like web application support, tarfile support, sql drivers, support for most kinds of commonly used crypto, command line flag parsing, html templating, and regular expressions. A full list of the standard library packages can be found here.

Variable type declarations will look backwards. It takes a bit to get used to but makes a lot of sense once you realize it reads better left to right.

For a nice primer on building web apps with Go, codegangsta is writing a book on the common first steps, starting from the standard library and working up. You can find his work in progress book here.

Go has support for unit testing baked into the core language tools. You can find information about writing unit tests here.

When creating a new go project, please resist the urge to make the folder in your normal code folder. Drink the $GOPATH koolaid. Yes it's annoying, yes it's the language forcing you to use its standard. Just try it. It's an amazingly useful thing once you get used to it.

Learn to love godoc. Godoc lets you document code like this. This also includes an example of the builtin unit testing support.