forked from kylelemons/goat
/
goat.go
134 lines (115 loc) · 3.01 KB
/
goat.go
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// Copyright 2013 Google, Inc. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// goat
//
// It is a basic example of terminal emulation with the "goat/term" package.
// It reads chunks in and writes them to standard output. Try typing a line
// and then hitting the up key on the next line. Try editing a previous line
// and hitting the up key again.
//
// Press ^C, ^D, or type "quit" to exit.
//
// If something happens and you can't exit, try "killall goat" from another
// terminal; this shouldn't happen, but it's possible.
package main
import (
"flag"
"io"
"log"
"os"
"github.com/kylelemons/goat/term"
"github.com/kylelemons/goat/termios"
)
var frame = flag.Bool("frame", false, "Do a frame demo instead of line editing")
func main() {
flag.Parse()
tio, err := termios.NewTermSettings(0)
if err != nil {
log.Fatalf("terminal: %s", err)
}
if err := tio.Raw(); err != nil {
log.Fatalf("rawterm: %s", err)
}
defer tio.Reset()
if *frame {
frameDemo(tio)
} else {
lineDemo()
}
}
func lineDemo() {
tty := term.NewTTY(os.Stdin)
// Prompt after each newline
prompt := func() {
io.WriteString(tty, "> ")
}
prompt()
// Allocate the line buffer and accumulator
linebuf := make([]byte, 128)
line := ""
for {
// Read from the TTY
n, err := tty.Read(linebuf)
if err != nil {
log.Printf("read: %s", err)
return
}
// Examine the chunk
switch str := string(linebuf[:n]); str {
case "quit", term.Interrupt, term.EndOfFile:
// Quit on "quit", ^C, and ^D
io.WriteString(os.Stdout, "Goodbye!\r\n")
return
case term.CarriageReturn, term.NewLine:
// Print out lines
log.Printf("read: %q\r\n", line)
prompt()
line = ""
default:
// Accumulate lines
line += str
}
}
}
func frameDemo(tio *termios.TermSettings) {
// Allocate a TTY connected to standard input
tty, region := term.NewFrameTTY(os.Stdin)
tty.Clear()
region.SetBorder(term.SimpleBorder)
width, height, err := tio.GetSize()
if err == nil && width > 0 && height > 0 {
region.SetSize(width, height)
}
region.Draw()
// Allocate the line buffer and accumulator
linebuf := make([]byte, 128)
for {
// Read from the TTY
n, err := tty.Read(linebuf)
if err != nil {
log.Printf("read: %s", err)
return
}
// Examine the chunk
switch str := string(linebuf[:n]); str {
case "quit", term.Interrupt, term.EndOfFile:
// Quit on "quit", ^C, and ^D
tty.Clear()
tty.SetCursor(0, 0)
io.WriteString(tty, "Goodbye!\r\n")
log.Printf("%dx%d\r", width, height)
return
}
}
}