Fix the size of terminal

Author: marcin-usielski

moler/io/raw/pty_process_unicode.py

@@ -9,6 +9,7 @@
 import os
 import pty
 import shlex
+import termios
 import subprocess
 
 from typing import Optional, Tuple, Union
@@ -71,6 +72,24 @@ def create_pty_process(self) -> None:
         self.process = process
         self._closed = False
 
+        # Apply initial terminal dimensions configured for this PTY.
+        self.setwinsize(*self.dimensions)
+
+    def setwinsize(self, rows: int, cols: int) -> None:
+        """
+        Set terminal dimensions of the pty process.
+        :param rows: terminal rows
+        :param cols: terminal columns
+        :return: None
+        """
+        if rows <= 0 or cols <= 0:
+            raise ValueError("Terminal dimensions must be positive")
+        if self.fd < 0:
+            raise MolerException("Cannot resize closed pty process")
+
+        termios.tcsetwinsize(self.fd, (rows, cols))
+        self.dimensions = (rows, cols)
+
     def write(self, data: Union[str, bytes]) -> int:
         """
         Write data to pty process.