1 files changed, 62 insertions, 0 deletions
diff --git a/doc/progs/file.go b/doc/progs/file.go
new file mode 100644
index 000000000..e2ecf9209
--- /dev/null
+++ b/doc/progs/file.go
@@ -0,0 +1,62 @@
+// 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.
+
+package file
+
+import (
+	"os";
+	"syscall";
+)
+
+type File struct {
+	fd      int64;  // file descriptor number
+	name    string; // file name at Open time
+}
+
+func newFile(fd int64, name string) *File {
+	if fd < 0 {
+		return nil
+	}
+	return &File{fd, name}
+}
+
+var (
+	Stdin  = newFile(0, "/dev/stdin");
+	Stdout = newFile(1, "/dev/stdout");
+	Stderr = newFile(2, "/dev/stderr");
+)
+
+func Open(name string, mode int64, perm int64) (file *File, err *os.Error) {
+	r, e := syscall.Open(name, mode, perm);
+	return newFile(r, name), os.ErrnoToError(e)
+}
+
+func (file *File) Close() *os.Error {
+	if file == nil {
+		return os.EINVAL
+	}
+	r, e := syscall.Close(file.fd);
+	file.fd = -1;  // so it can't be closed again
+	return nil
+}
+
+func (file *File) Read(b []byte) (ret int, err *os.Error) {
+	if file == nil {
+		return -1, os.EINVAL
+	}
+	r, e := syscall.Read(file.fd, &b[0], int64(len(b)));
+	return int(r), os.ErrnoToError(e)
+}
+
+func (file *File) Write(b []byte) (ret int, err *os.Error) {
+	if file == nil {
+		return -1, os.EINVAL
+	}
+	r, e := syscall.Write(file.fd, &b[0], int64(len(b)));
+	return int(r), os.ErrnoToError(e)
+}
+
+func (file *File) String() string {
+	return file.name
+}