"Fossies" - the Fresh Open Source Software Archive

Member "polysh-polysh-0.13/polysh/terminal_size.py" (11 May 2020, 2592 Bytes) of package /linux/privat/polysh-polysh-0.13.tar.gz:

As a special service "Fossies" has tried to format the requested source page into HTML format using (guessed) Python source code syntax highlighting (style: standard) with prefixed line numbers. Alternatively you can here view or download the uninterpreted source code file. For more information about "terminal_size.py" see the Fossies "Dox" file reference documentation. 
    1 """Polysh - Buffered Dispatcher Class
    2 
    3 Copyright (c) 2006 Guillaume Chazarain <guichaz@gmail.com>
    4 Copyright (c) 2018 InnoGames GmbH
    5 """
    6 # This program is free software: you can redistribute it and/or modify
    7 # it under the terms of the GNU General Public License as published by
    8 # the Free Software Foundation, either version 2 of the License, or
    9 # (at your option) any later version.
   10 #
   11 # This program is distributed in the hope that it will be useful,
   12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
   13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   14 # GNU General Public License for more details.
   15 #
   16 # You should have received a copy of the GNU General Public License
   17 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
   18 #
   19 # The code is taken from http://pdos.csail.mit.edu/~cblake/cls/cls.py
   20 # license in http://pdos.csail.mit.edu/~cblake/cls/cls_py_LICENSE reproduced
   21 # thereafter:
   22 # I, Charles Blake, hereby relinquish all rights to the functions
   23 # terminal_size() and ioctl_GWINSZ() in file cls.py, located in this
   24 # same code directory to the maximum extent applicable by this notice.
   25 #
   26 # These functions are provided "as is" and without any expressed or implied
   27 # warranties, including, without limitation, the implied warranties of
   28 # merchantibility and fitness for a particular purpose.
   29 #
   30 # It would be nice (but not necessary) to give me an artistic license credit
   31 # somewhere in the licensing materials of any derivative product.
   32 
   33 
   34 import os
   35 from typing import Tuple, Optional
   36 
   37 
   38 def _ioctl_GWINSZ(fd: int) -> Optional[Tuple[int, int]]:
   39     try:  # Discover terminal width
   40         import fcntl
   41         import termios
   42         import struct
   43         cr = struct.unpack('hh', fcntl.ioctl(fd, termios.TIOCGWINSZ, b'1234'))
   44     except BaseException:
   45         return None
   46     return int(cr[0]), int(cr[1])
   47 
   48 
   49 def terminal_size() -> Tuple[int, int]:  # decide on *some* terminal size
   50     """Return (lines, columns)."""
   51     cr = _ioctl_GWINSZ(0) or _ioctl_GWINSZ(
   52         1) or _ioctl_GWINSZ(2)  # try open fds
   53     if not cr:                                                  # ...then ctty
   54         try:
   55             fd = os.open(os.ctermid(), os.O_RDONLY)
   56             cr = _ioctl_GWINSZ(fd)
   57             os.close(fd)
   58         except BaseException:
   59             pass
   60         if not cr:                            # env vars or finally defaults
   61             try:
   62                 cr = int(os.environ['LINES']), int(os.environ['COLUMNS'])
   63             except BaseException:
   64                 cr = 25, 80
   65     return cr[1], cr[0]         # reverse rows, cols