Go项目工程管理及目录结构

GoGo

src 包含项目的源代码文件；
pkg 包含编译后生成的包/库文件；
bin 包含编译后生成的可执行文件。

可以通过下面的例子来说明工程目录的组织管理。(Windows 7 64位，go version go1.3.3 windows/amd64)

1. 创建一个库文件

a.go

package myfunc

import "fmt"

func Afunc(str string) {
	fmt.Println("a.go is package mufunc.")
	fmt.Println(str)
}

这时候目录结构如下：

<dirtest>
     |--<src>
          |--<mufunc>
                 |--a.go

2. 创建main

scr/main.go

package main

import "myfunc"

func main() {
	myfunc.Afunc("b.go is package main.")
}

这时候目录结构如下：

<dirtest>
     |--<src>
          |--<mufunc>
                 |--a.go
          |--<main>
                 |--b.go

3. 使用go build

go build

E:\dirtest>go build src\main\b.go

src\main\b.go:3:8: cannot find package "myfunc" in any of:
        C:\Program Files\go\src\pkg\myfunc (from $GOROOT)
        D:\GoLang\src\myfunc (from $GOPATH)

Go$GOROOTmyfunc$GOPATHgo envGo

E:\dirtest>go env

set GOARCH=amd64
set GOBIN=
set GOCHAR=6
set GOEXE=.exe
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOOS=windows
set GOPATH=D:\GoLang
set GORACE=
set GOROOT=C:\Program Files\go
set GOTOOLDIR=C:\Program Files\go\pkg\tool\windows_amd64
set CC=gcc
set GOGCCFLAGS=-m64 -mthreads -fmessage-length=0
set CXX=g++
set CGO_ENABLED=1

E:\dirtest$GOPATH

GOPATH

go buildb.exe

E:\dirtest\src\main>go env
set GOARCH=amd64
set GOBIN=
set GOCHAR=6
set GOEXE=.exe
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOOS=windows
set GOPATH=D:\GoLang;E:\dirtest
set GORACE=
set GOROOT=C:\Program Files\go
set GOTOOLDIR=C:\Program Files\go\pkg\tool\windows_amd64
set CC=gcc
set GOGCCFLAGS=-m64 -mthreads -fmessage-length=0
set CXX=g++
set CGO_ENABLED=1

E:\dirtest>go build src\main\b.go
E:\dirtest>dir

 E:\dirtest 的目录

2015/01/13  23:11    <DIR>          .
2015/01/13  23:11    <DIR>          ..
2015/01/13  23:11    1,958,912      b.exe
2015/01/13  22:52    <DIR>          src

E:\dirtest>b.exe
a.go is package mufunc.
b.go is package main.

go installgo install.go

go installE:\dirtestbin\main.exeD:\GoLang

go install

E:\dirtest\src\main>go install
go install: no install location for E:\dirtest\src\main: hidden by D:\GoLang\src
\main

$GOPATH$GOPATH

GOPATH

go install myfuncmyfunc.ago install mainmain.exe

<dirtest>
     |--<src>
          |--<mufunc>
                 |--a.go
          |--<main>
                 |--b.go
     |--<pkg>
          |--<windows_amd64>
                 |--myfunc.a
     |--<bin>
          |--main.exe

现在就算是成功完成了一个示例“项目”吧...

4. 常见错误

除了上面的步骤中出现的错误，其实工程目录管理稍有不慎，就会出现其他问题，例如：

a.gob.gomyfunc

这时候的目录结构如下：

<dirtest>
     |--<src>
          |--<mufunc>
                 |--a.go
                 |--b.go

go installgo buildgo run

E:\dirtest\src\myfunc>go install
can't load package: package myfunc: found packages myfunc (a.go) and main (b.go)
 in E:\dirtest\src\myfunc

E:\dirtest\src\myfunc>go build
can't load package: package myfunc: found packages myfunc (a.go) and main (b.go)
 in E:\dirtest\src\myfunc

E:\dirtest\src\myfunc>go run b.go
b.go:3:8: found packages myfunc (a.go) and main (b.go) in E:\dirtest\src\myfunc

从参考资料3中可以看到，每个子目录中只能存在一个package，否则编译时会报错，所以一个子目录下面不能包含多个不同包的源文件。

2. 一个项目能包含多个main()吗？

c.gomyfunc

package main
import "fmt"
import "myfunc"

func main() {
	fmt.Println("This is single c.go")
	myfunc.Afunc("c.go is also package main.")
}

执行相应的命令，结果如下：

E:\dirtest\src\main>go build
# main
.\c.go:4: main redeclared in this block
        previous declaration at .\b.go:5

E:\dirtest\src\main>go build c.go 
# 成功，当前目录下生成了c.exe

E:\dirtest\src\main>go install
# main
.\c.go:4: main redeclared in this block
        previous declaration at .\b.go:5

E:\dirtest\src\main>go install c.go
go install: no install location for .go files listed on command line (GOBIN not
set)

E:\dirtest\src\main>go run c.go
This is single c.go
a.go is package mufunc.
c.go is also package main.

go rungo build c.goc.go

E:\dirtest\src\cmain>dir

 E:\dirtest\src\cmain 的目录

2015/01/14  11:27    <DIR>          .
2015/01/14  11:27    <DIR>          ..
2015/01/14  11:24               147 c.go

E:\dirtest\src\cmain>go build

E:\dirtest\src\cmain>go install

go installexe

3. go install: no install location for .go files listed on command line (GOBIN not set)

go install$GOROOT$GOPATH$GOROOT/bin$GOPATH/bin$GOBIN=E:\dirtest\bin

GOPATH

E:\dirtest\src\cmain>go env
set GOARCH=amd64
set GOBIN=E:\dirtest\bin
set GOCHAR=6
set GOEXE=.exe
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOOS=windows
set GOPATH=E:\dirtest;D:\GoLang
set GORACE=
set GOROOT=C:\Program Files\go
set GOTOOLDIR=C:\Program Files\go\pkg\tool\windows_amd64
set CC=gcc
set GOGCCFLAGS=-m64 -mthreads -fmessage-length=0
set CXX=g++
set CGO_ENABLED=1

E:\dirtest\src\cmain>go install c.go
# 成功在 E:\dirtest\bin 下面生成 c.exe

go install

4. go build、go install 和 go run 的区别

详细的可以查看参考资料4，这里简单说一下：

go buildmain.ago install$GOPATH/bin$GOPATH/pkggo run gofiles...maingo run: cannot run non-main package

go run$GOPATHgo buildgo installgo run

5. 总结

$GOPATHsrc/proj1src/proj2go install