vendor/github.com/lib/pq/user_windows.go

// Package pq is a pure Go Postgres driver for the database/sql package.
package pq

import (
	"path/filepath"
	"syscall"
)

// Perform Windows user name lookup identically to libpq.
//
// The PostgreSQL code makes use of the legacy Win32 function
// GetUserName, and that function has not been imported into stock Go.
// GetUserNameEx is available though, the difference being that a
// wider range of names are available.  To get the output to be the
// same as GetUserName, only the base (or last) component of the
// result is returned.
func userCurrent() (string, error) {
	pw_name := make([]uint16, 128)
	pwname_size := uint32(len(pw_name)) - 1
	err := syscall.GetUserNameEx(syscall.NameSamCompatible, &pw_name[0], &pwname_size)
	if err != nil {
		return "", ErrCouldNotDetectUsername
	}
	s := syscall.UTF16ToString(pw_name)
	u := filepath.Base(s)
	return u, nil
}