Golang Package and Project composition

This is a creation in Article, where the information may have evolved or changed.

Working directory

First of all, the Golang working directory, after the installation of Golang, one thing to do is to set up a working directory, all projects, tools, third-party packages will be stored in the working directory. By default, the working directory is the folder for the user directory go . We can use environment variables GOPATH to change the location of the Golang working directory.

The structure of the working directory is as follows. A bin folder holds the various tools that the project will use, the library files required for the various packages required for the project, and pkc src the source code for the project. If a third-party library is used, the third-party library is also stored in the working directory.

bin/pkg/src/

Go command

Here's the GO command, which will be the main command we use. If you need to see Help, you can enter go it directly, and the terminal will list all the commands and brief prompts. I simply translated the Help information.

PS C:\Users\asddf> goGo is a tool for managing Go source code.Usage:        go command [arguments]The commands are:        build       编译包和依赖        clean       移除对象文件        doc         显示宝或符号的文档信息        env         打印go环境信息        bug         提交bug信息        fix         在包上运行go tool fix        fmt         在包源代码上运行格式化工具        generate    处理源代码并生成go文件        get         下载和安装包和依赖        install     编译并安装包和依赖        list        列出包        run         编译和运行go程序        test        测试包        tool        运行指定的go工具        version     打印go版本        vet         在包上运行go工具审查

Run the project

Single File

If you only need to run a single file, you can simply use the go run command. For example, the following code file is hello_world.go , then just need to run simply go run hello_world.go . Here, the package of the files that can be run must be main , and there is a main function.

package mainimport (    "fmt")func main() {    fmt.Println("Hello World")}

Complex projects

If we are writing a more complex project with a lot of packages, then we can't put the project at random. In order for a package in a project to be accessible, the project must be placed in the working directory of Go, and more specifically in the working directory src .

For example, my project can be placed in go_workspace\src\yitian\golang-study\golang-programming . Here, in order to differentiate between different third-party packages, a different directory hierarchy is required, such as the third-party library on most GitHub, at the directory level github.com/XXX .

Package

The concept of the package I put to the end, because I do not know how to say. However, if you learn Java, it should be easy to understand the concept of the package, anyway, is used to classify the code. It is important to note that the Java package is used to organize the code, so the Java package name must be unique, which is done by a long list of qualified names in front of the package abc.xyz.XXX .

Unlike Java, packages in Golang can have duplicate names, so in order to differentiate between different packages, you need to add a path at the time of the reference. Just take the project example, if go_workspace\src\yitian\golang-study\golang-programming there is a hello package, then in other projects to reference the package will need to use the name yitian/golang-study/golang-programming/hello .