diff options
Diffstat (limited to 'vendor/github.com/peterh/liner/output.go')
-rw-r--r-- | vendor/github.com/peterh/liner/output.go | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/vendor/github.com/peterh/liner/output.go b/vendor/github.com/peterh/liner/output.go new file mode 100644 index 000000000..6d83d4ebf --- /dev/null +++ b/vendor/github.com/peterh/liner/output.go @@ -0,0 +1,79 @@ +// +build linux darwin openbsd freebsd netbsd + +package liner + +import ( + "fmt" + "os" + "strings" + "syscall" + "unsafe" +) + +func (s *State) cursorPos(x int) { + if s.useCHA { + // 'G' is "Cursor Character Absolute (CHA)" + fmt.Printf("\x1b[%dG", x+1) + } else { + // 'C' is "Cursor Forward (CUF)" + fmt.Print("\r") + if x > 0 { + fmt.Printf("\x1b[%dC", x) + } + } +} + +func (s *State) eraseLine() { + fmt.Print("\x1b[0K") +} + +func (s *State) eraseScreen() { + fmt.Print("\x1b[H\x1b[2J") +} + +func (s *State) moveUp(lines int) { + fmt.Printf("\x1b[%dA", lines) +} + +func (s *State) moveDown(lines int) { + fmt.Printf("\x1b[%dB", lines) +} + +func (s *State) emitNewLine() { + fmt.Print("\n") +} + +type winSize struct { + row, col uint16 + xpixel, ypixel uint16 +} + +func (s *State) getColumns() bool { + var ws winSize + ok, _, _ := syscall.Syscall(syscall.SYS_IOCTL, uintptr(syscall.Stdout), + syscall.TIOCGWINSZ, uintptr(unsafe.Pointer(&ws))) + if int(ok) < 0 { + return false + } + s.columns = int(ws.col) + if cursorColumn && s.columns > 1 { + s.columns-- + } + return true +} + +func (s *State) checkOutput() { + // xterm is known to support CHA + if strings.Contains(strings.ToLower(os.Getenv("TERM")), "xterm") { + s.useCHA = true + return + } + + // The test for functional ANSI CHA is unreliable (eg the Windows + // telnet command does not support reading the cursor position with + // an ANSI DSR request, despite setting TERM=ansi) + + // Assume CHA isn't supported (which should be safe, although it + // does result in occasional visible cursor jitter) + s.useCHA = false +} |