Merge pull request #201 from Victorious3/issue174

Correct terminal size on Windows and >= py33

Author: nicoddemus

CHANGELOG

@@ -1,3 +1,10 @@
+1.7.0 (unreleased)
+==================
+
+- fix #174: use ``shutil.get_terminal_size()`` in Python 3.3+ to determine the size of the
+  terminal, which produces more accurate results than the previous method.
+
+
 1.6.0 (2018-08-27)
 ==================
 

py/_io/terminalwriter.py

@@ -8,6 +8,7 @@
 import sys, os, unicodedata
 import py
 py3k = sys.version_info[0] >= 3
+py33 = sys.version_info >= (3, 3)
 from py.builtin import text, bytes
 
 win32_and_ctypes = False
@@ -24,10 +25,15 @@
 
 
 def _getdimensions():
-    import termios,fcntl,struct
-    call = fcntl.ioctl(1,termios.TIOCGWINSZ,"\000"*8)
-    height,width = struct.unpack( "hhhh", call ) [:2]
-    return height, width
+    if py33:
+        import shutil
+        size = shutil.get_terminal_size()
+        return size.lines, size.columns
+    else:
+        import termios, fcntl, struct
+        call = fcntl.ioctl(1, termios.TIOCGWINSZ, "\000" * 8)
+        height, width = struct.unpack("hhhh", call)[:2]
+        return height, width
 
 
 def get_terminal_width():

testing/io_/test_terminalwriter.py

@@ -1,3 +1,4 @@
+from collections import namedtuple
 
 import py
 import os, sys
@@ -10,16 +11,22 @@ def test_get_terminal_width():
     assert x == terminalwriter.get_terminal_width
 
 def test_getdimensions(monkeypatch):
-    fcntl = py.test.importorskip("fcntl")
-    import struct
-    l = []
-    monkeypatch.setattr(fcntl, 'ioctl', lambda *args: l.append(args))
-    try:
-        terminalwriter._getdimensions()
-    except (TypeError, struct.error):
-        pass
-    assert len(l) == 1
-    assert l[0][0] == 1
+    if sys.version_info >= (3, 3):
+        import shutil
+        Size = namedtuple('Size', 'lines columns')
+        monkeypatch.setattr(shutil, 'get_terminal_size', lambda: Size(60, 100))
+        assert terminalwriter._getdimensions() == (60, 100)
+    else:
+        fcntl = py.test.importorskip("fcntl")
+        import struct
+        l = []
+        monkeypatch.setattr(fcntl, 'ioctl', lambda *args: l.append(args))
+        try:
+            terminalwriter._getdimensions()
+        except (TypeError, struct.error):
+            pass
+        assert len(l) == 1
+        assert l[0][0] == 1
 
 def test_terminal_width_COLUMNS(monkeypatch):
     """ Dummy test for get_terminal_width