summaryrefslogtreecommitdiff
path: root/src/pkg/os/env.go
diff options
context:
space:
mode:
Diffstat (limited to 'src/pkg/os/env.go')
-rw-r--r--src/pkg/os/env.go80
1 files changed, 80 insertions, 0 deletions
diff --git a/src/pkg/os/env.go b/src/pkg/os/env.go
new file mode 100644
index 000000000..748750413
--- /dev/null
+++ b/src/pkg/os/env.go
@@ -0,0 +1,80 @@
+// Copyright 2009 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.
+
+// Environment variables.
+
+package os
+
+import (
+ "once";
+ "os";
+)
+
+// ENOENV is the Error indicating that an environment variable does not exist.
+var ENOENV = NewError("no such environment variable");
+
+var env map[string] string;
+
+
+func copyenv() {
+ env = make(map[string] string);
+ for i, s := range os.Envs {
+ for j := 0; j < len(s); j++ {
+ if s[j] == '=' {
+ env[s[0:j]] = s[j+1:len(s)];
+ break;
+ }
+ }
+ }
+}
+
+// Getenv retrieves the value of the environment variable named by the key.
+// It returns the value and an error, if any.
+func Getenv(key string) (value string, err Error) {
+ once.Do(copyenv);
+
+ if len(key) == 0 {
+ return "", EINVAL;
+ }
+ v, ok := env[key];
+ if !ok {
+ return "", ENOENV;
+ }
+ return v, nil;
+}
+
+// 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;
+ }
+ env[key] = value;
+ return nil;
+}
+
+// Clearenv deletes all environment variables.
+func Clearenv() {
+ once.Do(copyenv); // prevent copyenv in Getenv/Setenv
+ env = make(map[string] string);
+}
+
+// Environ returns an array of strings representing the environment,
+// in the form "key=value".
+func Environ() []string {
+ once.Do(copyenv);
+ a := make([]string, len(env));
+ i := 0;
+ for k, v := range(env) {
+ // check i < len(a) for safety,
+ // in case env is changing underfoot.
+ if i < len(a) {
+ a[i] = k + "=" + v;
+ i++;
+ }
+ }
+ return a[0:i];
+}