gsh/terminal_size.py

   1 # from http://pdos.csail.mit.edu/~cblake/cls/cls.py
   2
   3 import os
   4
   5 def _ioctl_GWINSZ(fd):                  #### TABULATION FUNCTIONS
   6     try:                                ### Discover terminal width
   7         import fcntl
   8         import termios
   9         import struct
  10         cr = struct.unpack('hh', fcntl.ioctl(fd, termios.TIOCGWINSZ, '1234'))
  11     except:
  12         return
  13     return cr
  14
  15 def terminal_size():                    ### decide on *some* terminal size
  16     """Return (lines, columns)."""
  17     cr = _ioctl_GWINSZ(0) or _ioctl_GWINSZ(1) or _ioctl_GWINSZ(2) # try open fds
  18     if not cr:                                                  # ...then ctty
  19         try:
  20             fd = os.open(os.ctermid(), os.O_RDONLY)
  21             cr = _ioctl_GWINSZ(fd)
  22             os.close(fd)
  23         except:
  24             pass
  25         if not cr:                            # env vars or finally defaults
  26             try:
  27                 cr = os.environ['LINES'], os.environ['COLUMNS']
  28             except:
  29                 cr = 25, 80
  30     return int(cr[1]), int(cr[0])         # reverse rows, cols