diff options
| -rw-r--r-- | blessings/__init__.py | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/blessings/__init__.py b/blessings/__init__.py index b135e01..bee547e 100644 --- a/blessings/__init__.py +++ b/blessings/__init__.py @@ -217,7 +217,10 @@ class Terminal(object): return self._height_and_width()[1] def _height_and_width(self): - """Return a tuple of (terminal height, terminal width).""" + """Return a tuple of (terminal height, terminal width), + using TIOCGWINSZ (Terminal I/O-Control: Get Window Size), + falling back to environment variables (LINES, COLUMNS), + and 25 x 80 when otherwise unavailable.""" # tigetnum('lines') and tigetnum('cols') update only if we call # setupterm() again. for descriptor in self._init_descriptor, sys.__stdout__: @@ -225,8 +228,13 @@ class Terminal(object): return struct.unpack( 'hhhh', ioctl(descriptor, TIOCGWINSZ, '\000' * 8))[0:2] except IOError: + # when the output stream or init descriptor is not a tty, such + # as when when stdout is piped to another program, fe. tee(1), + # these ioctls will raise IOError pass - return None, None # Should never get here + lines, cols = (int(environ.get('LINES', '24')), + int(environ.get('COLUMNS', '80'))) + return lines, cols @contextmanager def location(self, x=None, y=None): |