diff --git a/IPython/genutils.py b/IPython/genutils.py index 09cc9ea..5b5f852 100644 --- a/IPython/genutils.py +++ b/IPython/genutils.py @@ -33,6 +33,18 @@ import time import types import warnings +# Curses and termios are Unix-only modules +try: + import curses + # We need termios as well, so if its import happens to raise, we bail on + # using curses altogether. + import termios +except ImportError: + USE_CURSES = False +else: + # Curses on Solaris may not be complete, so we can't use it there + USE_CURSES = hasattr(curses,'initscr') + # Other IPython utilities import IPython from IPython.Itpl import Itpl,itpl,printpl @@ -1548,26 +1560,30 @@ def page(strng,start=0,screen_lines=0,pager_cmd = None): # auto-determine screen size if screen_lines <= 0: if TERM=='xterm': - try: - import curses - if hasattr(curses,'initscr'): - use_curses = 1 - else: - use_curses = 0 - except ImportError: - use_curses = 0 + use_curses = USE_CURSES else: # curses causes problems on many terminals other than xterm. - use_curses = 0 + use_curses = False if use_curses: - scr = curses.initscr() - screen_lines_real,screen_cols = scr.getmaxyx() - curses.endwin() - screen_lines += screen_lines_real - #print '***Screen size:',screen_lines_real,'lines x',\ - #screen_cols,'columns.' # dbg + # There is a bug in curses, where *sometimes* it fails to properly + # initialize, and then after the endwin() call is made, the + # terminal is left in an unusable state. Rather than trying to + # check everytime for this (by requesting and comparing termios + # flags each time), we just save the initial terminal state and + # unconditionally reset it every time. It's cheaper than making + # the checks. + term_flags = termios.tcgetattr(sys.stdout) + scr = curses.initscr() + screen_lines_real,screen_cols = scr.getmaxyx() + curses.endwin() + # Restore terminal state in case endwin() didn't. + termios.tcsetattr(sys.stdout,termios.TCSANOW,term_flags) + # Now we have what we needed: the screen size in rows/columns + screen_lines += screen_lines_real + #print '***Screen size:',screen_lines_real,'lines x',\ + #screen_cols,'columns.' # dbg else: - screen_lines += screen_lines_def + screen_lines += screen_lines_def #print 'numlines',numlines,'screenlines',screen_lines # dbg if numlines <= screen_lines : diff --git a/doc/ChangeLog b/doc/ChangeLog index 680ba37..a32b2dd 100644 --- a/doc/ChangeLog +++ b/doc/ChangeLog @@ -1,3 +1,8 @@ +2008-04-18 Fernando Perez + + * IPython/genutils.py (page): apply workaround to curses bug that + can leave terminal corrupted after a call to initscr(). + 2008-04-15 Ville Vainio * genutils.py: SList.grep supports 'field' argument