1 files changed, 113 insertions, 0 deletions
diff --git a/libgo/go/os/env_windows.go b/libgo/go/os/env_windows.go
new file mode 100644
index 00000000000..6908a9ca85b
--- /dev/null
+++ b/libgo/go/os/env_windows.go
@@ -0,0 +1,113 @@
+// 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.
+
+// Windows environment variables.
+
+package os
+
+import (
+	"syscall"
+	"utf16"
+	"unsafe"
+)
+
+// ENOENV is the Error indicating that an environment variable does not exist.
+var ENOENV = NewError("no such environment variable")
+
+// 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) {
+	b := make([]uint16, 100)
+	n, e := syscall.GetEnvironmentVariable(syscall.StringToUTF16Ptr(key), &b[0], uint32(len(b)))
+	if n == 0 && e == syscall.ERROR_ENVVAR_NOT_FOUND {
+		return "", ENOENV
+	}
+	if n > uint32(len(b)) {
+		b = make([]uint16, n)
+		n, e = syscall.GetEnvironmentVariable(syscall.StringToUTF16Ptr(key), &b[0], uint32(len(b)))
+		if n > uint32(len(b)) {
+			n = 0
+		}
+	}
+	if n == 0 {
+		return "", NewSyscallError("GetEnvironmentVariable", e)
+	}
+	return string(utf16.Decode(b[0:n])), 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 {
+	var v *uint16
+	if len(value) > 0 {
+		v = syscall.StringToUTF16Ptr(value)
+	}
+	ok, e := syscall.SetEnvironmentVariable(syscall.StringToUTF16Ptr(key), v)
+	if !ok {
+		return NewSyscallError("SetEnvironmentVariable", e)
+	}
+	return nil
+}
+
+// Clearenv deletes all environment variables.
+func Clearenv() {
+	for _, s := range Environ() {
+		// Environment variables can begin with =
+		// so start looking for the separator = at j=1.
+		// http://blogs.msdn.com/b/oldnewthing/archive/2010/05/06/10008132.aspx
+		for j := 1; j < len(s); j++ {
+			if s[j] == '=' {
+				Setenv(s[0:j], "")
+				break
+			}
+		}
+	}
+}
+
+// Environ returns an array of strings representing the environment,
+// in the form "key=value".
+func Environ() []string {
+	s, e := syscall.GetEnvironmentStrings()
+	if e != 0 {
+		return nil
+	}
+	defer syscall.FreeEnvironmentStrings(s)
+	r := make([]string, 0, 50) // Empty with room to grow.
+	for from, i, p := 0, 0, (*[1 << 24]uint16)(unsafe.Pointer(s)); true; i++ {
+		if p[i] == 0 {
+			// empty string marks the end
+			if i <= from {
+				break
+			}
+			r = append(r, string(utf16.Decode(p[from:i])))
+			from = i + 1
+		}
+	}
+	return r
+}
+
+// TempDir returns the default directory to use for temporary files.
+func TempDir() string {
+	const pathSep = '\\'
+	dirw := make([]uint16, syscall.MAX_PATH)
+	n, _ := syscall.GetTempPath(uint32(len(dirw)), &dirw[0])
+	if n > uint32(len(dirw)) {
+		dirw = make([]uint16, n)
+		n, _ = syscall.GetTempPath(uint32(len(dirw)), &dirw[0])
+		if n > uint32(len(dirw)) {
+			n = 0
+		}
+	}
+	if n > 0 && dirw[n-1] == pathSep {
+		n--
+	}
+	return string(utf16.Decode(dirw[0:n]))
+}