| // Copyright 2020 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| //go:build windows |
| |
| package execenv |
| |
| import ( |
| "internal/syscall/windows" |
| "syscall" |
| "unsafe" |
| ) |
| |
| // Default will return the default environment |
| // variables based on the process attributes |
| // provided. |
| // |
| // If the process attributes contain a token, then |
| // the environment variables will be sourced from |
| // the defaults for that user token, otherwise they |
| // will be sourced from syscall.Environ(). |
| func Default(sys *syscall.SysProcAttr) (env []string, err error) { |
| if sys == nil || sys.Token == 0 { |
| return syscall.Environ(), nil |
| } |
| var blockp *uint16 |
| err = windows.CreateEnvironmentBlock(&blockp, sys.Token, false) |
| if err != nil { |
| return nil, err |
| } |
| defer windows.DestroyEnvironmentBlock(blockp) |
| |
| const size = unsafe.Sizeof(*blockp) |
| for *blockp != 0 { // environment block ends with empty string |
| // find NUL terminator |
| end := unsafe.Add(unsafe.Pointer(blockp), size) |
| for *(*uint16)(end) != 0 { |
| end = unsafe.Add(end, size) |
| } |
| |
| entry := unsafe.Slice(blockp, (uintptr(end)-uintptr(unsafe.Pointer(blockp)))/2) |
| env = append(env, syscall.UTF16ToString(entry)) |
| blockp = (*uint16)(unsafe.Add(end, size)) |
| } |
| return |
| } |