polysh/console.py

   1 # This program is free software; you can redistribute it and/or modify
   2 # it under the terms of the GNU General Public License as published by
   3 # the Free Software Foundation; either version 2 of the License, or
   4 # (at your option) any later version.
   5 #
   6 # This program is distributed in the hope that it will be useful,
   7 # but WITHOUT ANY WARRANTY; without even the implied warranty of
   8 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9 # GNU Library General Public License for more details.
  10 #
  11 # You should have received a copy of the GNU General Public License
  12 # along with this program; if not, write to the Free Software
  13 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  14 #
  15 # See the COPYING file for license information.
  16 #
  17 # Copyright (c) 2006 Guillaume Chazarain <guichaz@gmail.com>
  18
  19 import errno
  20 import sys
  21
  22 # We remember the length of the last printed status in order to
  23 # clear it with ' ' characters
  24 last_status_length = None
  25
  26 def safe_write(output, buf):
  27     """We can get a SIGWINCH when printing, which will cause write to raise
  28     an EINTR. That's not a reason to stop printing."""
  29     while True:
  30         try:
  31             output.write(buf)
  32             break
  33         except IOError, e:
  34             if e.errno != errno.EINTR:
  35                 raise
  36
  37 def console_output(msg, logging_msg=None):
  38     """Use instead of print, to clear the status information before printing"""
  39     from polysh import remote_dispatcher
  40
  41     remote_dispatcher.log(logging_msg or msg)
  42     if remote_dispatcher.options.interactive:
  43         from polysh.stdin import the_stdin_thread
  44         the_stdin_thread.no_raw_input()
  45         global last_status_length
  46         if last_status_length:
  47             safe_write(sys.stdout, '\r' + last_status_length * ' ' + '\r')
  48             last_status_length = 0
  49     safe_write(sys.stdout, msg)
  50
  51 def set_last_status_length(length):
  52     """The length of the prefix to be cleared when printing something"""
  53     global last_status_length
  54     last_status_length = length
  55