1 files changed, 109 insertions, 0 deletions
diff --git a/src/pkg/os/env_unix.go b/src/pkg/os/env_unix.go
new file mode 100644
index 000000000..9cc0b03d8
--- /dev/null
+++ b/src/pkg/os/env_unix.go
@@ -0,0 +1,109 @@
+// 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.
+
+// Unix environment variables.
+
+package os
+
+import (
+	"sync"
+)
+
+// ENOENV is the Error indicating that an environment variable does not exist.
+var ENOENV = NewError("no such environment variable")
+
+var env map[string]string
+var once sync.Once
+
+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
+
+// Getenverror retrieves the value of the environment variable named by the key.
+// It returns the value and an error, if any.
+func Getenverror(key string) (value string, err Error) {
+	once.Do(copyenv)
+
+	if len(key) == 0 {
+		return "", EINVAL
+	}
+
+	envLock.RLock()
+	defer envLock.RUnlock()
+
+	v, ok := env[key]
+	if !ok {
+		return "", ENOENV
+	}
+	return v, nil
+}
+
+// Getenv retrieves the value of the environment variable named by the key.
+// It returns the value, which will be empty if the variable is not present.
+func Getenv(key string) string {
+	v, _ := Getenverror(key)
+	return v
+}
+
+// Setenv sets the value of the environment variable named by the key.
+// It returns an Error, if any.
+func Setenv(key, value string) Error {
+	once.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
+}
+
+// Clearenv deletes all environment variables.
+func Clearenv() {
+	once.Do(copyenv) // prevent copyenv in Getenv/Setenv
+
+	envLock.Lock()
+	defer envLock.Unlock()
+
+	env = make(map[string]string)
+
+	// TODO(bradfitz): pass through to C
+}
+
+// Environ returns an array of strings representing the environment,
+// in the form "key=value".
+func Environ() []string {
+	once.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
+}
+
+// TempDir returns the default directory to use for temporary files.
+func TempDir() string {
+	dir := Getenv("TMPDIR")
+	if dir == "" {
+		dir = "/tmp"
+	}
+	return dir
+}