blob: 2c873cbbad3395dd3befb6d4f6ce139efc7c228d [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.
// +build darwin freebsd linux netbsd openbsd
// Unix environment variables.
package syscall
import "sync"
var env map[string]string
var envOnce sync.Once
var envs []string // provided by runtime
func setenv_c(k, v string)
func copyenv() {
env = make(map[string]string)
for _, s := range envs {
for j := 0; j < len(s); j++ {
if s[j] == '=' {
env[s[0:j]] = s[j+1:]
break
}
}
}
}
var envLock sync.RWMutex
func Getenv(key string) (value string, found bool) {
envOnce.Do(copyenv)
if len(key) == 0 {
return "", false
}
envLock.RLock()
defer envLock.RUnlock()
v, ok := env[key]
if !ok {
return "", false
}
return v, true
}
func Setenv(key, value string) error {
envOnce.Do(copyenv)
if len(key) == 0 {
return EINVAL
}
envLock.Lock()
defer envLock.Unlock()
env[key] = value
setenv_c(key, value) // is a no-op if cgo isn't loaded
return nil
}
func Clearenv() {
envOnce.Do(copyenv) // prevent copyenv in Getenv/Setenv
envLock.Lock()
defer envLock.Unlock()
env = make(map[string]string)
// TODO(bradfitz): pass through to C
}
func Environ() []string {
envOnce.Do(copyenv)
envLock.RLock()
defer envLock.RUnlock()
a := make([]string, len(env))
i := 0
for k, v := range env {
a[i] = k + "=" + v
i++
}
return a
}