How to get current GOPATH from code

Question

How do I get the current GOPATH from a block of code?

runtime only has GOROOT:

// GOROOT returns the root of the Go tree.
// It uses the GOROOT environment variable, if set,
// or else the root used during the Go build.
func GOROOT() string {
    s := gogetenv("GOROOT")
    if s != "" {
        return s
    }
    return defaultGoroot
}

I could make a function that has GOROOT replaced with GOPATH, but is there a buildin for this?

Answer 1

Use os.Getenv

From docs:

Getenv retrieves the value of the environment variable named by the key. It returns the value, which will be empty if the variable is not present.

Example:

package main

import (
    "fmt"
    "os"
    )

func main() {
    fmt.Println(os.Getenv("GOPATH"))
}

Update for Go 1.8+

Go 1.8 has default GOPATH exported via go/build:

package main

import (
    "fmt"
    "go/build"
    "os"
)

func main() {
    gopath := os.Getenv("GOPATH")
    if gopath == "" {
        gopath = build.Default.GOPATH
    }
    fmt.Println(gopath)
}

Answer 2

You should use go/build package.

package main

import (
    "fmt"
    "go/build"
)

func main() {
    fmt.Println(build.Default.GOPATH)
}