diff options
Diffstat (limited to 'src/pkg/os/env.go')
-rw-r--r-- | src/pkg/os/env.go | 80 |
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]; +} |