102 lines
2.7 KiB
Go
102 lines
2.7 KiB
Go
|
// Copyright 2017 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.
|
||
|
|
|
||
|
|
package terminal
|
||
|
|
|
||
|
|
import (
|
||
|
|
"bytes"
|
||
|
|
"io"
|
||
|
|
"os"
|
||
|
|
"syscall"
|
||
|
|
"unsafe"
|
||
|
|
)
|
||
|
|
|
||
|
|
func isTerminal(w io.Writer) bool {
|
||
|
|
if f, ok := w.(*os.File); ok {
|
||
|
|
var termios syscall.Termios
|
||
|
|
_, _, err := syscall.Syscall6(syscall.SYS_IOCTL, f.Fd(),
|
||
|
|
ioctlGetTermios, uintptr(unsafe.Pointer(&termios)),
|
||
|
|
0, 0, 0)
|
||
|
|
return err == 0
|
||
|
|
}
|
||
|
|
return false
|
||
|
|
}
|
||
|
|
|
||
|
|
func termWidth(w io.Writer) (int, bool) {
|
||
|
|
if f, ok := w.(*os.File); ok {
|
||
|
|
var winsize struct {
|
||
|
|
ws_row, ws_column uint16
|
||
|
|
ws_xpixel, ws_ypixel uint16
|
||
|
|
}
|
||
|
|
_, _, err := syscall.Syscall6(syscall.SYS_IOCTL, f.Fd(),
|
||
|
|
syscall.TIOCGWINSZ, uintptr(unsafe.Pointer(&winsize)),
|
||
|
|
0, 0, 0)
|
||
|
|
return int(winsize.ws_column), err == 0
|
||
|
|
}
|
||
|
|
return 0, false
|
||
|
|
}
|
||
|
|
|
||
|
|
// stripAnsiEscapes strips ANSI control codes from a byte array in place.
|
||
|
|
func stripAnsiEscapes(input []byte) []byte {
|
||
|
|
// read represents the remaining part of input that needs to be processed.
|
||
|
|
read := input
|
||
|
|
// write represents where we should be writing in input.
|
||
|
|
// It will share the same backing store as input so that we make our modifications
|
||
|
|
// in place.
|
||
|
|
write := input
|
||
|
|
|
||
|
|
// advance will copy count bytes from read to write and advance those slices
|
||
|
|
advance := func(write, read []byte, count int) ([]byte, []byte) {
|
||
|
|
copy(write, read[:count])
|
||
|
|
return write[count:], read[count:]
|
||
|
|
}
|
||
|
|
|
||
|
|
for {
|
||
|
|
// Find the next escape sequence
|
||
|
|
i := bytes.IndexByte(read, 0x1b)
|
||
|
|
// If it isn't found, or if there isn't room for <ESC>[, finish
|
||
|
|
if i == -1 || i+1 >= len(read) {
|
||
|
|
copy(write, read)
|
||
|
|
break
|
||
|
|
}
|
||
|
|
|
||
|
|
// Not a CSI code, continue searching
|
||
|
|
if read[i+1] != '[' {
|
||
|
|
write, read = advance(write, read, i+1)
|
||
|
|
continue
|
||
|
|
}
|
||
|
|
|
||
|
|
// Found a CSI code, advance up to the <ESC>
|
||
|
|
write, read = advance(write, read, i)
|
||
|
|
|
||
|
|
// Find the end of the CSI code
|
||
|
|
i = bytes.IndexFunc(read, func(r rune) bool {
|
||
|
|
return (r >= 'a' && r <= 'z') || (r >= 'A' && r <= 'Z')
|
||
|
|
})
|
||
|
|
if i == -1 {
|
||
|
|
// We didn't find the end of the code, just remove the rest
|
||
|
|
i = len(read) - 1
|
||
|
|
}
|
||
|
|
|
||
|
|
// Strip off the end marker too
|
||
|
|
i = i + 1
|
||
|
|
|
||
|
|
// Skip the reader forward and reduce final length by that amount
|
||
|
|
read = read[i:]
|
||
|
|
input = input[:len(input)-i]
|
||
|
|
}
|
||
|
|
|
||
|
|
return input
|
||
|
|
}
|