// Copyright 2010 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. // Windows environment variables. package syscall import ( "unicode/utf16" "unsafe" ) func Getenv(key string) (value string, found bool) { keyp, err := UTF16PtrFromString(key) if err != nil { return "", false } b := make([]uint16, 100) n, e := GetEnvironmentVariable(keyp, &b[0], uint32(len(b))) if n == 0 && e == ERROR_ENVVAR_NOT_FOUND { return "", false } if n > uint32(len(b)) { b = make([]uint16, n) n, e = GetEnvironmentVariable(keyp, &b[0], uint32(len(b))) if n > uint32(len(b)) { n = 0 } } if n == 0 { return "", false } return string(utf16.Decode(b[0:n])), true } func Setenv(key, value string) error { var v *uint16 var err error if len(value) > 0 { v, err = UTF16PtrFromString(value) if err != nil { return err } } keyp, err := UTF16PtrFromString(key) if err != nil { return err } e := SetEnvironmentVariable(keyp, v) if e != nil { return e } return nil } func Clearenv() { for _, s := range Environ() { // Environment variables can begin with = // so start looking for the separator = at j=1. // http://blogs.msdn.com/b/oldnewthing/archive/2010/05/06/10008132.aspx for j := 1; j < len(s); j++ { if s[j] == '=' { Setenv(s[0:j], "") break } } } } 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 }