C-Cpp-Go

Go语言精简总结(Part One) - The way to Go

安装

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$ apt-get install bison ed gawk libc6-dev mercurial python-setuptools python-dev build-essential
$ hg clone -r release https://go.googlecode.com/hg/ go
$ export GOROOT=$HOME/go
$ export GOARCH=amd64
$ export GOOS=linux
$ export GOTOOL=$HOME/go/pkg/tool/linux_amd64/
$ export PATH=.:$PATH:$GOBIN:$GOTOOL
$ cd go/src
$ ./all.bash

更新go版本

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$ cd $GOROOT && hg identify
$ hg pull && hg update release
$ ./all.bash

Workspace 示例

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bin/
    todo                               # command executable
pkg/
    linux_amd64/
        code.google.com/p/goauth2/
            oauth.a                    # package object
        github.com/nf/todo/            task.a                   
src/
    code.google.com/p/goauth2/
        .hg/                           # mercurial repository metadata
        oauth/
            oauth.go                  # package source
            oauth_test.go             # test source
    github.com/nf/
        todo/
            .git/
            task/
                task.go                # package source
            todo.go

hello, world

  • 例子1
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package main
import "fmt"
func main() {
     fmt.Printf("hello, world\n")
}
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$ 6g helloworld.go
$ 6l helloworld.6
$ ./6.out        或者         $ go run helloworld.go
  • 例子2
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$HOME/HelloWorldWorkspace/
bin/
    helloworld                      # after go install
pkg/
src/
    github.com/msolo/helloworld
        .git
        helloworld.go
 
$ export GOPATH=$HOME/HelloWorldWorkspace
$ go install github.com/msolo/helloworld
$ $GOPATH/bin/helloworld

使用自定义包/库

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package main
import (
    "fmt"
    "github.com/user/newmath"
)
func main() {
     fmt.Printf("Hello, world.  Sqrt(2) = %v\n", newmath.Sqrt(2))
}
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package newmath
// Sqrt returns an approximation to the square root of x.
func Sqrt(x float64) float64 {
     z := 1.0
     for i := 0; i < 1000; i++ {
         z -= (z*z - x) / (2 * z)
     }
     return z
}
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$HOME/HelloWorldWorkspace/
bin/
    helloworld
pkg/
    linux_amd64/                  # reflect your OS and architecture
        github.com/user/
            newmath.a             # package object
src/
    github.com/user/helloworld
            helloworld.go
    github.com/user/newmath
            sqrt.go
 
$ go install github.com/user/helloworld