Installation

If you know about installation or have installed Go, you can skip to Tools.

This chapter is taken from install page verbatim, except for the changes to be made to adapt to this book's styling format.

System requirements

Go binary distributions are available for these supported operating systems and architectures. Please ensure your system meets these requirements before proceeding. If your OS or architecture is not on the list, you may be able to install from source or use gccgo instead

†gcc is required only if you plan to use cgo.

‡You only need to install the command line tools for Xcode. If you have already installed Xcode 4.3+, you can install it from the Components tab of the Downloads preferences panel.

Install the Go tools

If you are upgrading from an older version of Go you must first remove the existing version. Linux, Mac OS X, and FreeBSD tarballs

Download the archive and extract it into /usr/local, creating a Go tree in /usr/local/go. For example:

tar -C /usr/local -xzf go$VERSION.$OS-$ARCH.tar.gz

Choose the archive file appropriate for your installation. For instance, if you are installing Go version 1.2.1 for 64-bit x86 on Linux, the archive you want is called go1.2.1.linux-amd64.tar.gz.

(Typically these commands must be run as root or through sudo.)

Add/usr/local/go/bin to the PATH environment variable. You can do this by adding this line to your /etc/profile (for a system-wide installation) or $HOME/.profile:

export PATH=$PATH:/usr/local/go/bin

Installing to a custom location

The Go binary distributions assume they will be installed in /usr/local/go (or c:\Go under Windows), but it is possible to install the Go tools to a different location. In this case you must set the GOROOT environment variable to point to the directory in which it was installed.

For example, if you installed Go to your home directory you should add the following commands to $HOME/.profile:

export GOROOT=$HOME/go

export PATH=$PATH:$GOROOT/bin

Note: GOROOT must be set only when installing to a custom location.

Mac OS X package installer

Download the package file, open it, and follow the prompts to install the Go tools. The package installs the Go distribution to /usr/local/go.

The package should put the /usr/local/go/bin directory in your PATH environment variable. You may need to restart any open Terminal sessions for the change to take effect.

Windows

The Go project provides two installation options for Windows users (besides installing from source): a zip archive that requires you to set some environment variables and an MSI installer that configures your installation automatically.

MSI installer

Open the MSI file and follow the prompts to install the Go tools. By default, the installer puts the Go distribution in c:\Go.

The installer should put the c:\Go\bin directory in your PATH environment variable. You may need to restart any open command prompts for the change to take effect.

Zip archive

Download the zip file and extract it into the directory of your choice (we suggest c:\Go).

If you chose a directory other than c:\Go, you must set the GOROOT environment variable to your chosen path.

Add the bin subdirectory of your Go root (for example, c:\Go\bin) to your PATH environment variable.

Setting environment variables under Windows

Under Windows, you may set environment variables through the "Environment Variables" button on the "Advanced" tab of the "System" control panel. Some versions of Windows provide this control panel through the "Advanced System Settings" option inside the "System" control panel.

Test your installation

Check that Go is installed correctly by setting up a workspace and building a simple program, as follows.

Create a directory to contain your workspace, $HOME/work for example, and set the GOPATH environment variable to point to that location.

$ export GOPATH=$HOME/work

You should put the above command in your shell startup script ($HOME/.profile for example) or, if you use Windows, follow the instructions above to set the GOPATH environment variable on your system.

Next, make the directories src/github.com/user/hello inside your workspace (if you use GitHub, substitute your user name for user), and inside the hello directory create a file named hello.go with the following contents:

    package main

    import "fmt"

    func main() {
        fmt.Printf("hello, world\n")
    }

Then compile it with the go tool:

   $ go install github.com/user/hello

The above command will put an executable command named hello (or hello.exe) inside the bin directory of your workspace. Execute the command to see the greeting:

    $ $GOPATH/bin/hello

hello, world

If you see the "hello, world" message then your Go installation is working.

Before rushing off to write Go code please read the How to Write Go Code document, which describes some essential concepts about using the Go tools.

Uninstalling Go

To remove an existing Go installation from your system delete the go directory. This is usually /usr/local/go under Linux, Mac OS X, and FreeBSD or c:\Go under Windows.

You should also remove the Go bin directory from your PATH environment variable. Under Linux and FreeBSD you should edit /etc/profile or $HOME/.profile. If you installed Go with the Mac OS X package then you should remove the /etc/paths.d/go file. Windows users should read the section about setting environment variables under Windows.

Getting help

For real-time help, ask the helpful gophers in #go-nuts on the Freenode IRC server.

The official mailing list for discussion of the Go language is Go Nuts.

Report bugs using the Go issue tracker.

Links

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