windows.Environ（）字符串[0]和[1]

Question

I'm confused by the first 2 strings returned by "windows.Environ()" on a Windows pro 7 system (go version go1.8 windows/amd64). env[0] apparently has a key of "=::"; env[1] has a key "=C:". Can anyone point me to where this is documented? Thx in advance.

str_EnvStrs := windows.Environ()
// 
//    str_EnvStrs[0] == '=::=::\'
fmt.Printf("str_EnvStrs[0] == '%v'
",str_EnvStrs[0])
//
//    str_EnvStrs[1] == '=C:=C:\Users\(WINLOGIN)\Documents\Source\go\src 
//                       \github.com\(GITLOGIN)\maps_arrays_slices'
fmt.Printf("str_EnvStrs[1] == '%v'
",str_EnvStrs[1])

Answer 1

The relevant Go code is:

func Environ() []string {
    s, e := GetEnvironmentStrings()
    if e != nil {
        return nil
    }
    defer FreeEnvironmentStrings(s)
    r := make([]string, 0, 50) // Empty with room to grow.
    for from, i, p := 0, 0, (*[1 << 24]uint16)(unsafe.Pointer(s)); true; i++ {
        if p[i] == 0 {
            // empty string marks the end
            if i <= from {
                break
            }
            r = append(r, string(utf16.Decode(p[from:i])))
            from = i + 1
        }
    }
    return r
}

The code is using the Windows GetEnvironmentStrings function. The values come from Windows. See the Microsoft Windows documentation of environment variables. Also, see What are these strange =C: environment variables?