title: How do I evaluate a environment variable using Go's os/exec
body: <p>How do I get Go to evaluate the $PATH variable. I currently just prints
  "$PATH" </p>
  
  <p>I have the following code</p>
  
  <pre><code>package main
  
  import (
          "fmt"
          "log"
          "os/exec"
  )
  
  func main() {
          out, err := exec.Command("echo","$PATH").Output()
          if err != nil {
                  log.Fatal(err)
          }
          fmt.Printf("%s\n",out)
  }
  </code></pre>