Merge pull request astaxie#788 from vCaesar/up10-pr

Update go install and fix set Go env

Author: astaxie

en/01.1.md

@@ -76,15 +76,15 @@ A 64-bit operating system will show the following:
 
 ### Mac
 
-Go to the [download page](https://golang.org/dl/), choose `go1.4.2.darwin-386.pkg` for 32-bit systems and `go1.7.4.darwin-amd64.pkg` for 64-bit systems. Going all the way to the end by clicking "next", `~/go/bin` will be added to your system's $PATH after you finish the installation. Now open the terminal and type `go`. You should see the same output shown in figure 1.1.
+Go to the [download page](https://golang.org/dl/), choose `go1.4.2.darwin-386.pkg` (The later version has no 32-bit download.)for 32-bit systems and `go1.8.darwin-amd64.pkg` for 64-bit systems. Going all the way to the end by clicking "next", `~/go/bin` will be added to your system's $PATH after you finish the installation. Now open the terminal and type `go`. You should see the same output shown in figure 1.1.
 
 ### Linux
 
-Go to the [download page](https://golang.org/dl/), choose `go1.7.4.linux-386.tar.gz` for 32-bit systems and `go1.7.4.linux-amd64.tar.gz` for 64-bit systems. Suppose you want to install Go in the `$GO_INSTALL_DIR` path. Uncompress the `tar.gz` to your chosen path using the command `tar zxvf go1.7.4.linux-amd64.tar.gz -C $GO_INSTALL_DIR`. Then set your $PATH with the following: `export PATH=$PATH:$GO_INSTALL_DIR/go/bin`. Now just open the terminal and type `go`. You should now see the same output displayed in figure 1.1.
+Go to the [download page](https://golang.org/dl/), choose `go1.8.linux-386.tar.gz` for 32-bit systems and `go1.8.linux-amd64.tar.gz` for 64-bit systems. Suppose you want to install Go in the `$GO_INSTALL_DIR` path. Uncompress the `tar.gz` to your chosen path using the command `tar zxvf go1.8.linux-amd64.tar.gz -C $GO_INSTALL_DIR`. Then set your $PATH with the following: `export PATH=$PATH:$GO_INSTALL_DIR/go/bin`. Now just open the terminal and type `go`. You should now see the same output displayed in figure 1.1.
 
 ### Windows
 
-Go to the [download page](https://golang.org/dl/), choose `go1.7.4.windows-386.msi` for 32-bit systems and `go1.7.4.windows-amd64.msi` for 64-bit systems. Going all the way to the end by clicking "next", `c:/go/bin` will be added to `path`. Now just open a command line window and type `go`. You should now see the same output displayed in figure 1.1.
+Go to the [download page](https://golang.org/dl/), choose `go1.8.windows-386.msi` for 32-bit systems and `go1.8.windows-amd64.msi` for 64-bit systems. Going all the way to the end by clicking "next", `c:/go/bin` will be added to `path`. Now just open a command line window and type `go`. You should now see the same output displayed in figure 1.1.
 
 ## Use third-party tools
 
@@ -96,8 +96,8 @@ GVM is a Go multi-version control tool developed by a third-party, like rvm for
 
 Then we install Go using the following commands:
 
-    gvm install go1.7.4
-    gvm use go1.7.4
+    gvm install go1.8
+    gvm use go1.8
 
 After the process has finished, you're all set.
 
@@ -112,13 +112,16 @@ Ubuntu is the most popular desktop release version of Linux. It uses `apt-get` t
 ###wget
 ```sh
 
-wget https://storage.googleapis.com/golang/go1.7.4.linux-amd64.tar.gz
-sudo tar -xzf go1.7.4.linux-amd64.tar.gz -C /usr/local 
-export PATH=PATH:/usr/local/go/binexportGOROOT=HOME/go 
-export PATH=PATH:GOROOT/bin 
-export GOPATH=HOME/gowork 
-```    
+wget https://storage.googleapis.com/golang/go1.8.linux-amd64.tar.gz
+sudo tar -xzf go1.8.linux-amd64.tar.gz -C /usr/local 
 
+# Go environment
+export GOROOT=/usr/local/go
+export GOBIN=$GOROOT/bin
+export PATH=$PATH:$GOBIN
+export GOPATH=HOME/gopath 
+```    
+Starting from go 1.8,The GOPATH environment variable now has a default value if it is unset. It defaults to $HOME/go on Unix and %USERPROFILE%/go on Windows.
 ### Homebrew
 
 Homebrew is a software management tool commonly used in Mac to manage packages. Just type the following commands to install Go.

en/01.2.md

@@ -4,6 +4,8 @@
 
 Go takes a unique approach to manage the code files with the introduction of a `$GOPATH` directory which contains all the go code in the machine. Note that this is different from the `$GOROOT` environment variable which states where go is installed on the machine. We have to define the $GOPATH variable before using the language, in *nix systems there is a file called `.bashrc` we need to append the below export statement to the file. The concept behind gopath is a novel one, where we can link to any go code at any instant of time without ambiguity.
 
+Starting from go 1.8,The GOPATH environment variable now has a default value if it is unset. It defaults to $HOME/go on Unix and %USERPROFILE%/go on Windows.
+
 In Unix-like systems, the variable should be used like this:
 
 	export GOPATH=/home/apple/mygo

zh/01.1.md

@@ -46,6 +46,7 @@ Go 1.5彻底移除C代码，Runtime、Compiler、Linker均由Go编写,实现自
 
 如果出现Go的Usage信息，那么说明Go已经安装成功了；如果出现该命令不存在，那么可以检查一下自己的PATH环境变中是否包含了Go的安装目录。
 
+从go 1.8开始，GOPATH环境变量现在有一个默认值，如果它没有被设置。 它在Unix上默认为$HOME/go,在Windows上默认为%USERPROFILE%/go。
 > 关于上面的GOPATH将在下面小节详细讲解
 
 ## Go标准包安装
@@ -78,19 +79,19 @@ Linux系统用户可通过在Terminal中执行命令`arch`(即`uname -m`)来查
 
 ### Mac 安装
 
-访问[下载地址][downlink]，32位系统下载go1.4.2.darwin-386-osx10.8.pkg(最新版已无32位下载)，64位系统下载go1.7.4.darwin-amd64.pkg，双击下载文件，一路默认安装点击下一步，这个时候go已经安装到你的系统中，默认已经在PATH中增加了相应的`~/go/bin`,这个时候打开终端，输入`go`
+访问[下载地址][downlink]，32位系统下载go1.4.2.darwin-386-osx10.8.pkg(更新版已无32位下载)，64位系统下载go1.8.darwin-amd64.pkg，双击下载文件，一路默认安装点击下一步，这个时候go已经安装到你的系统中，默认已经在PATH中增加了相应的`~/go/bin`,这个时候打开终端，输入`go`
 
 看到类似上面源码安装成功的图片说明已经安装成功
 
 如果出现go的Usage信息，那么说明go已经安装成功了；如果出现该命令不存在，那么可以检查一下自己的PATH环境变中是否包含了go的安装目录。
 
 ### Linux 安装
 
-访问[下载地址][downlink]，32位系统下载go1.7.4.linux-386.tar.gz，64位系统下载go1.7.4.linux-amd64.tar.gz，
+访问[下载地址][downlink]，32位系统下载go1.8.linux-386.tar.gz，64位系统下载go1.8.linux-amd64.tar.gz，
 
 假定你想要安装Go的目录为 `$GO_INSTALL_DIR`，后面替换为相应的目录路径。
 
-解压缩`tar.gz`包到安装目录下：`tar zxvf go1.7.4.linux-amd64.tar.gz -C $GO_INSTALL_DIR`。
+解压缩`tar.gz`包到安装目录下：`tar zxvf go1.8.linux-amd64.tar.gz -C $GO_INSTALL_DIR`。
 
 设置PATH，`export PATH=$PATH:$GO_INSTALL_DIR/go/bin`
 
@@ -104,7 +105,7 @@ Linux系统用户可通过在Terminal中执行命令`arch`(即`uname -m`)来查
 
 ### Windows 安装 ###
 
-访问[Google Code 下载页][downlink]，32 位请选择名称中包含 windows-386 的 msi 安装包，64 位请选择名称中包含 windows-amd64 的。下载好后运行，不要修改默认安装目录 C:\Go\，若安装到其他位置会导致不能执行自己所编写的 Go 代码。安装完成后默认会在环境变量 Path 后添加 Go 安装目录下的 bin 目录 `C:\Go\bin\`，并添加环境变量 GOROOT，值为 Go 安装根目录 `C:\Go\` 。
+访问[Golang 下载页][downlink]，32 位请选择名称中包含 windows-386 的 msi 安装包，64 位请选择名称中包含 windows-amd64 的。下载好后运行，不要修改默认安装目录 C:\Go\，若安装到其他位置会导致不能执行自己所编写的 Go 代码。安装完成后默认会在环境变量 Path 后添加 Go 安装目录下的 bin 目录 `C:\Go\bin\`，并添加环境变量 GOROOT，值为 Go 安装根目录 `C:\Go\` 。
 
 **验证是否安装成功**
 
@@ -124,11 +125,11 @@ gvm是第三方开发的Go多版本管理工具，类似ruby里面的rvm工具
 安装完成后我们就可以安装go了：
 ```sh
 
-	gvm install go1.7.4
-	gvm use go1.7.4
+	gvm install go1.8
+	gvm use go1.8
 ```
 也可以使用下面的命令，省去每次调用gvm use的麻烦：
-        gvm use go1.7.4 --default
+        gvm use go1.8 --default
 
 执行完上面的命令之后GOPATH、GOROOT等环境变量会自动设置好，这样就可以直接使用了。
 
@@ -144,11 +145,28 @@ Ubuntu是目前使用最多的Linux桌面系统，使用`apt-get`命令来管理
 ###wget
 ```sh
 
-wget https://storage.googleapis.com/golang/go1.7.4.linux-amd64.tar.gz
-sudo tar -xzf go1.7.4.linux-amd64.tar.gz -C /usr/local 
-export PATH=PATH:/usr/local/go/binexportGOROOT=HOME/go 
-export PATH=PATH:GOROOT/bin 
-export GOPATH=HOME/gowork 
+wget https://storage.googleapis.com/golang/go1.8.linux-amd64.tar.gz
+sudo tar -xzf go1.8.linux-amd64.tar.gz -C /usr/local 
+```
+
+配置环境变量:
+```sh
+
+export GOROOT=/usr/local/go
+export GOBIN=$GOROOT/bin
+export PATH=$PATH:$GOBIN
+export GOPATH=HOME/gopath (可选设置)
+```
+或者使用: 
+```sh 
+sudo vim /etc/profile 
+```
+并添加下面的内容：
+```sh
+export GOROOT=/usr/local/go
+export GOBIN=$GOROOT/bin
+export PATH=$PATH:$GOBIN
+export GOPATH=HOME/gopath (可选设置)
 ```
 
 ### homebrew

zh/01.2.md

@@ -1,7 +1,8 @@
 # 1.2 GOPATH与工作空间
 
-前面我们在安装Go的时候看到需要设置GOPATH变量，Go从1.1版本开始必须设置这个变量，而且不能和Go的安装目录一样，这个目录用来存放Go源码，Go的可运行文件，以及相应的编译之后的包文件。所以这个目录下面有三个子目录：src、bin、pkg
+前面我们在安装Go的时候看到需要设置GOPATH变量，Go从1.1版本到1.7必须设置这个变量，而且不能和Go的安装目录一样，这个目录用来存放Go源码，Go的可运行文件，以及相应的编译之后的包文件。所以这个目录下面有三个子目录：src、bin、pkg
 
+从go 1.8开始，GOPATH环境变量现在有一个默认值，如果它没有被设置。 它在Unix上默认为$HOME/go,在Windows上默认为%USERPROFILE%/go。
 ## GOPATH设置
   go 命令依赖一个重要的环境变量：$GOPATH