blob: 74b154ec1519e3c10b5e0fed46f8ca5698ccd261 [file] [log] [blame]
// 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
}
n := uint32(100)
for {
b := make([]uint16, n)
n, err = GetEnvironmentVariable(keyp, &b[0], uint32(len(b)))
if n == 0 && err == ERROR_ENVVAR_NOT_FOUND {
return "", false
}
if n <= uint32(len(b)) {
return string(utf16.Decode(b[:n])), true
}
}
}
func Setenv(key, value string) error {
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 Unsetenv(key string) error {
keyp, err := UTF16PtrFromString(key)
if err != nil {
return err
}
return SetEnvironmentVariable(keyp, nil)
}
func Clearenv() {
for _, s := range Environ() {
// Environment variables can begin with =
// so start looking for the separator = at j=1.
// https://blogs.msdn.com/b/oldnewthing/archive/2010/05/06/10008132.aspx
for j := 1; j < len(s); j++ {
if s[j] == '=' {
Unsetenv(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
}