syscall: take over env implementation
The environment is needed by package time, which
we want not to depend on os (so that os can use
time.Time), so push down into syscall.
Delete syscall.Sleep, now unnecessary.
The package os environment API is preserved;
it is only the implementation that is moving to syscall.
Delete os.Envs, which was undocumented,
uninitialized on Windows and Plan 9, and
not maintained by Setenv and Clearenv.
Code can call os.Environ instead.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5370091
diff --git a/src/pkg/syscall/env_unix.go b/src/pkg/syscall/env_unix.go
new file mode 100644
index 0000000..94a64713
--- /dev/null
+++ b/src/pkg/syscall/env_unix.go
@@ -0,0 +1,85 @@
+// 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 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
+}
