Add termstatus

internal/ui/termstatus/terminal_posix.go

@@ -0,0 +1,33 @@
+package termstatus
+
+import (
+	"fmt"
+	"io"
+	"os"
+)
+
+const (
+	posixMoveCursorHome = "\r"
+	posixMoveCursorUp   = "\x1b[1A"
+	posixClearLine      = "\x1b[2K"
+)
+
+// posixClearLines will clear the current line and the n lines above.
+// Afterwards the cursor is positioned at the start of the first cleared line.
+func posixClearLines(wr io.Writer, fd uintptr, n int) {
+	// clear current line
+	_, err := wr.Write([]byte(posixMoveCursorHome + posixClearLine))
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "write failed: %v\n", err)
+		return
+	}
+
+	for ; n > 0; n-- {
+		// clear current line and move on line up
+		_, err := wr.Write([]byte(posixMoveCursorUp + posixClearLine))
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "write failed: %v\n", err)
+			return
+		}
+	}
+}