##// END OF EJS Templates
Backport PR #2738: Unicode content crashes the pager (console)...
Backport PR #2738: Unicode content crashes the pager (console) We've run into an interesting bug in the astropy project. https://github.com/astropy/astropy/issues/600 When displaying a docstring that contains Unicode and is also long enough that it gets sent to the pager it fails since the docstring can't be sent to the pager as ascii. This crashes in the middle of sending content to the pager, so the shell ends up in an inconsistent state and stops echoing the keyboard etc. The fix (attached) is merely to encode the content sent to the pager in the same encoding as the terminal (`sys.stdout.encoding`). Strictly speaking, this isn't always the right thing to do, since the pager may be configured to expect a different encoding than the terminal, but that is sort of an irrational way to configure a machine... ;) For example, `less`, in the absence of any special environment variables to tell it otherwise, uses the standard `LC*` environment variables to determine what to do, which should be the same mechanism the terminal also uses by default. If anyone can suggest a better fix, I'm all for it. Perhaps it should be configurable, defaulting to `sys.stdout.encoding`?

File last commit:

r5846:51bd31a9
r9853:7f9a133e
Show More
history_console_widget.py
283 lines | 10.5 KiB | text/x-python | PythonLexer
/ IPython / frontend / qt / console / history_console_widget.py
# System library imports
from IPython.external.qt import QtGui
# Local imports
from IPython.utils.traitlets import Bool
from console_widget import ConsoleWidget
class HistoryConsoleWidget(ConsoleWidget):
""" A ConsoleWidget that keeps a history of the commands that have been
executed and provides a readline-esque interface to this history.
"""
#------ Configuration ------------------------------------------------------
# If enabled, the input buffer will become "locked" to history movement when
# an edit is made to a multi-line input buffer. To override the lock, use
# Shift in conjunction with the standard history cycling keys.
history_lock = Bool(False, config=True)
#---------------------------------------------------------------------------
# 'object' interface
#---------------------------------------------------------------------------
def __init__(self, *args, **kw):
super(HistoryConsoleWidget, self).__init__(*args, **kw)
# HistoryConsoleWidget protected variables.
self._history = []
self._history_edits = {}
self._history_index = 0
self._history_prefix = ''
#---------------------------------------------------------------------------
# 'ConsoleWidget' public interface
#---------------------------------------------------------------------------
def execute(self, source=None, hidden=False, interactive=False):
""" Reimplemented to the store history.
"""
if not hidden:
history = self.input_buffer if source is None else source
executed = super(HistoryConsoleWidget, self).execute(
source, hidden, interactive)
if executed and not hidden:
# Save the command unless it was an empty string or was identical
# to the previous command.
history = history.rstrip()
if history and (not self._history or self._history[-1] != history):
self._history.append(history)
# Emulate readline: reset all history edits.
self._history_edits = {}
# Move the history index to the most recent item.
self._history_index = len(self._history)
return executed
#---------------------------------------------------------------------------
# 'ConsoleWidget' abstract interface
#---------------------------------------------------------------------------
def _up_pressed(self, shift_modifier):
""" Called when the up key is pressed. Returns whether to continue
processing the event.
"""
prompt_cursor = self._get_prompt_cursor()
if self._get_cursor().blockNumber() == prompt_cursor.blockNumber():
# Bail out if we're locked.
if self._history_locked() and not shift_modifier:
return False
# Set a search prefix based on the cursor position.
col = self._get_input_buffer_cursor_column()
input_buffer = self.input_buffer
if self._history_index == len(self._history) or \
(self._history_prefix and col != len(self._history_prefix)):
self._history_index = len(self._history)
self._history_prefix = input_buffer[:col]
# Perform the search.
self.history_previous(self._history_prefix,
as_prefix=not shift_modifier)
# Go to the first line of the prompt for seemless history scrolling.
# Emulate readline: keep the cursor position fixed for a prefix
# search.
cursor = self._get_prompt_cursor()
if self._history_prefix:
cursor.movePosition(QtGui.QTextCursor.Right,
n=len(self._history_prefix))
else:
cursor.movePosition(QtGui.QTextCursor.EndOfLine)
self._set_cursor(cursor)
return False
return True
def _down_pressed(self, shift_modifier):
""" Called when the down key is pressed. Returns whether to continue
processing the event.
"""
end_cursor = self._get_end_cursor()
if self._get_cursor().blockNumber() == end_cursor.blockNumber():
# Bail out if we're locked.
if self._history_locked() and not shift_modifier:
return False
# Perform the search.
replaced = self.history_next(self._history_prefix,
as_prefix=not shift_modifier)
# Emulate readline: keep the cursor position fixed for a prefix
# search. (We don't need to move the cursor to the end of the buffer
# in the other case because this happens automatically when the
# input buffer is set.)
if self._history_prefix and replaced:
cursor = self._get_prompt_cursor()
cursor.movePosition(QtGui.QTextCursor.Right,
n=len(self._history_prefix))
self._set_cursor(cursor)
return False
return True
#---------------------------------------------------------------------------
# 'HistoryConsoleWidget' public interface
#---------------------------------------------------------------------------
def history_previous(self, substring='', as_prefix=True):
""" If possible, set the input buffer to a previous history item.
Parameters:
-----------
substring : str, optional
If specified, search for an item with this substring.
as_prefix : bool, optional
If True, the substring must match at the beginning (default).
Returns:
--------
Whether the input buffer was changed.
"""
index = self._history_index
replace = False
while index > 0:
index -= 1
history = self._get_edited_history(index)
if (as_prefix and history.startswith(substring)) \
or (not as_prefix and substring in history):
replace = True
break
if replace:
self._store_edits()
self._history_index = index
self.input_buffer = history
return replace
def history_next(self, substring='', as_prefix=True):
""" If possible, set the input buffer to a subsequent history item.
Parameters:
-----------
substring : str, optional
If specified, search for an item with this substring.
as_prefix : bool, optional
If True, the substring must match at the beginning (default).
Returns:
--------
Whether the input buffer was changed.
"""
index = self._history_index
replace = False
while self._history_index < len(self._history):
index += 1
history = self._get_edited_history(index)
if (as_prefix and history.startswith(substring)) \
or (not as_prefix and substring in history):
replace = True
break
if replace:
self._store_edits()
self._history_index = index
self.input_buffer = history
return replace
def history_tail(self, n=10):
""" Get the local history list.
Parameters:
-----------
n : int
The (maximum) number of history items to get.
"""
return self._history[-n:]
def _request_update_session_history_length(self):
msg_id = self.kernel_manager.shell_channel.execute('',
silent=True,
user_expressions={
'hlen':'len(get_ipython().history_manager.input_hist_raw)',
}
)
self._request_info['execute'][msg_id] = self._ExecutionRequest(msg_id, 'save_magic')
def _handle_execute_reply(self, msg):
""" Handles replies for code execution, here only session history length
"""
msg_id = msg['parent_header']['msg_id']
info = self._request_info['execute'].pop(msg_id,None)
if info and info.kind == 'save_magic' and not self._hidden:
content = msg['content']
status = content['status']
if status == 'ok':
self._max_session_history=(int(content['user_expressions']['hlen']))
def save_magic(self):
# update the session history length
self._request_update_session_history_length()
file_name,extFilter = QtGui.QFileDialog.getSaveFileName(self,
"Enter A filename",
filter='Python File (*.py);; All files (*.*)'
)
# let's the user search/type for a file name, while the history length
# is fetched
if file_name:
hist_range, ok = QtGui.QInputDialog.getText(self,
'Please enter an interval of command to save',
'Saving commands:',
text=str('1-'+str(self._max_session_history))
)
if ok:
self.execute("%save"+" "+file_name+" "+str(hist_range))
#---------------------------------------------------------------------------
# 'HistoryConsoleWidget' protected interface
#---------------------------------------------------------------------------
def _history_locked(self):
""" Returns whether history movement is locked.
"""
return (self.history_lock and
(self._get_edited_history(self._history_index) !=
self.input_buffer) and
(self._get_prompt_cursor().blockNumber() !=
self._get_end_cursor().blockNumber()))
def _get_edited_history(self, index):
""" Retrieves a history item, possibly with temporary edits.
"""
if index in self._history_edits:
return self._history_edits[index]
elif index == len(self._history):
return unicode()
return self._history[index]
def _set_history(self, history):
""" Replace the current history with a sequence of history items.
"""
self._history = list(history)
self._history_edits = {}
self._history_index = len(self._history)
def _store_edits(self):
""" If there are edits to the current input buffer, store them.
"""
current = self.input_buffer
if self._history_index == len(self._history) or \
self._history[self._history_index] != current:
self._history_edits[self._history_index] = current