1// Copyright 2018 Google Inc. All rights reserved.
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15// Package terminal provides a set of interfaces that can be used to interact
16// with the terminal (including falling back when the terminal is detected to
17// be a redirect or other dumb terminal)
18package terminal
19
20import (
21	"io"
22	"os"
23)
24
25// StdioInterface represents a set of stdin/stdout/stderr Reader/Writers
26type StdioInterface interface {
27	Stdin() io.Reader
28	Stdout() io.Writer
29	Stderr() io.Writer
30}
31
32// StdioImpl uses the OS stdin/stdout/stderr to implement StdioInterface
33type StdioImpl struct{}
34
35func (StdioImpl) Stdin() io.Reader  { return os.Stdin }
36func (StdioImpl) Stdout() io.Writer { return os.Stdout }
37func (StdioImpl) Stderr() io.Writer { return os.Stderr }
38
39var _ StdioInterface = StdioImpl{}
40
41type customStdio struct {
42	stdin  io.Reader
43	stdout io.Writer
44	stderr io.Writer
45}
46
47func NewCustomStdio(stdin io.Reader, stdout, stderr io.Writer) StdioInterface {
48	return customStdio{stdin, stdout, stderr}
49}
50
51func (c customStdio) Stdin() io.Reader  { return c.stdin }
52func (c customStdio) Stdout() io.Writer { return c.stdout }
53func (c customStdio) Stderr() io.Writer { return c.stderr }
54
55var _ StdioInterface = customStdio{}
56