|
|
# encoding: utf-8
|
|
|
"""
|
|
|
IO related utilities.
|
|
|
"""
|
|
|
|
|
|
#-----------------------------------------------------------------------------
|
|
|
# Copyright (C) 2008-2011 The IPython Development Team
|
|
|
#
|
|
|
# Distributed under the terms of the BSD License. The full license is in
|
|
|
# the file COPYING, distributed as part of this software.
|
|
|
#-----------------------------------------------------------------------------
|
|
|
from __future__ import print_function
|
|
|
from __future__ import absolute_import
|
|
|
|
|
|
#-----------------------------------------------------------------------------
|
|
|
# Imports
|
|
|
#-----------------------------------------------------------------------------
|
|
|
import codecs
|
|
|
from contextlib import contextmanager
|
|
|
import io
|
|
|
import os
|
|
|
import shutil
|
|
|
import stat
|
|
|
import sys
|
|
|
import tempfile
|
|
|
from .capture import CapturedIO, capture_output
|
|
|
from .py3compat import string_types, input, PY3
|
|
|
|
|
|
#-----------------------------------------------------------------------------
|
|
|
# Code
|
|
|
#-----------------------------------------------------------------------------
|
|
|
|
|
|
|
|
|
class IOStream:
|
|
|
|
|
|
def __init__(self,stream, fallback=None):
|
|
|
if not hasattr(stream,'write') or not hasattr(stream,'flush'):
|
|
|
if fallback is not None:
|
|
|
stream = fallback
|
|
|
else:
|
|
|
raise ValueError("fallback required, but not specified")
|
|
|
self.stream = stream
|
|
|
self._swrite = stream.write
|
|
|
|
|
|
# clone all methods not overridden:
|
|
|
def clone(meth):
|
|
|
return not hasattr(self, meth) and not meth.startswith('_')
|
|
|
for meth in filter(clone, dir(stream)):
|
|
|
setattr(self, meth, getattr(stream, meth))
|
|
|
|
|
|
def __repr__(self):
|
|
|
cls = self.__class__
|
|
|
tpl = '{mod}.{cls}({args})'
|
|
|
return tpl.format(mod=cls.__module__, cls=cls.__name__, args=self.stream)
|
|
|
|
|
|
def write(self,data):
|
|
|
try:
|
|
|
self._swrite(data)
|
|
|
except:
|
|
|
try:
|
|
|
# print handles some unicode issues which may trip a plain
|
|
|
# write() call. Emulate write() by using an empty end
|
|
|
# argument.
|
|
|
print(data, end='', file=self.stream)
|
|
|
except:
|
|
|
# if we get here, something is seriously broken.
|
|
|
print('ERROR - failed to write data to stream:', self.stream,
|
|
|
file=sys.stderr)
|
|
|
|
|
|
def writelines(self, lines):
|
|
|
if isinstance(lines, string_types):
|
|
|
lines = [lines]
|
|
|
for line in lines:
|
|
|
self.write(line)
|
|
|
|
|
|
# This class used to have a writeln method, but regular files and streams
|
|
|
# in Python don't have this method. We need to keep this completely
|
|
|
# compatible so we removed it.
|
|
|
|
|
|
@property
|
|
|
def closed(self):
|
|
|
return self.stream.closed
|
|
|
|
|
|
def close(self):
|
|
|
pass
|
|
|
|
|
|
# setup stdin/stdout/stderr to sys.stdin/sys.stdout/sys.stderr
|
|
|
devnull = open(os.devnull, 'w')
|
|
|
stdin = IOStream(sys.stdin, fallback=devnull)
|
|
|
stdout = IOStream(sys.stdout, fallback=devnull)
|
|
|
stderr = IOStream(sys.stderr, fallback=devnull)
|
|
|
|
|
|
class IOTerm:
|
|
|
""" Term holds the file or file-like objects for handling I/O operations.
|
|
|
|
|
|
These are normally just sys.stdin, sys.stdout and sys.stderr but for
|
|
|
Windows they can can replaced to allow editing the strings before they are
|
|
|
displayed."""
|
|
|
|
|
|
# In the future, having IPython channel all its I/O operations through
|
|
|
# this class will make it easier to embed it into other environments which
|
|
|
# are not a normal terminal (such as a GUI-based shell)
|
|
|
def __init__(self, stdin=None, stdout=None, stderr=None):
|
|
|
mymodule = sys.modules[__name__]
|
|
|
self.stdin = IOStream(stdin, mymodule.stdin)
|
|
|
self.stdout = IOStream(stdout, mymodule.stdout)
|
|
|
self.stderr = IOStream(stderr, mymodule.stderr)
|
|
|
|
|
|
|
|
|
class Tee(object):
|
|
|
"""A class to duplicate an output stream to stdout/err.
|
|
|
|
|
|
This works in a manner very similar to the Unix 'tee' command.
|
|
|
|
|
|
When the object is closed or deleted, it closes the original file given to
|
|
|
it for duplication.
|
|
|
"""
|
|
|
# Inspired by:
|
|
|
# http://mail.python.org/pipermail/python-list/2007-May/442737.html
|
|
|
|
|
|
def __init__(self, file_or_name, mode="w", channel='stdout'):
|
|
|
"""Construct a new Tee object.
|
|
|
|
|
|
Parameters
|
|
|
----------
|
|
|
file_or_name : filename or open filehandle (writable)
|
|
|
File that will be duplicated
|
|
|
|
|
|
mode : optional, valid mode for open().
|
|
|
If a filename was give, open with this mode.
|
|
|
|
|
|
channel : str, one of ['stdout', 'stderr']
|
|
|
"""
|
|
|
if channel not in ['stdout', 'stderr']:
|
|
|
raise ValueError('Invalid channel spec %s' % channel)
|
|
|
|
|
|
if hasattr(file_or_name, 'write') and hasattr(file_or_name, 'seek'):
|
|
|
self.file = file_or_name
|
|
|
else:
|
|
|
self.file = open(file_or_name, mode)
|
|
|
self.channel = channel
|
|
|
self.ostream = getattr(sys, channel)
|
|
|
setattr(sys, channel, self)
|
|
|
self._closed = False
|
|
|
|
|
|
def close(self):
|
|
|
"""Close the file and restore the channel."""
|
|
|
self.flush()
|
|
|
setattr(sys, self.channel, self.ostream)
|
|
|
self.file.close()
|
|
|
self._closed = True
|
|
|
|
|
|
def write(self, data):
|
|
|
"""Write data to both channels."""
|
|
|
self.file.write(data)
|
|
|
self.ostream.write(data)
|
|
|
self.ostream.flush()
|
|
|
|
|
|
def flush(self):
|
|
|
"""Flush both channels."""
|
|
|
self.file.flush()
|
|
|
self.ostream.flush()
|
|
|
|
|
|
def __del__(self):
|
|
|
if not self._closed:
|
|
|
self.close()
|
|
|
|
|
|
|
|
|
def ask_yes_no(prompt, default=None, interrupt=None):
|
|
|
"""Asks a question and returns a boolean (y/n) answer.
|
|
|
|
|
|
If default is given (one of 'y','n'), it is used if the user input is
|
|
|
empty. If interrupt is given (one of 'y','n'), it is used if the user
|
|
|
presses Ctrl-C. Otherwise the question is repeated until an answer is
|
|
|
given.
|
|
|
|
|
|
An EOF is treated as the default answer. If there is no default, an
|
|
|
exception is raised to prevent infinite loops.
|
|
|
|
|
|
Valid answers are: y/yes/n/no (match is not case sensitive)."""
|
|
|
|
|
|
answers = {'y':True,'n':False,'yes':True,'no':False}
|
|
|
ans = None
|
|
|
while ans not in answers.keys():
|
|
|
try:
|
|
|
ans = input(prompt+' ').lower()
|
|
|
if not ans: # response was an empty string
|
|
|
ans = default
|
|
|
except KeyboardInterrupt:
|
|
|
if interrupt:
|
|
|
ans = interrupt
|
|
|
except EOFError:
|
|
|
if default in answers.keys():
|
|
|
ans = default
|
|
|
print()
|
|
|
else:
|
|
|
raise
|
|
|
|
|
|
return answers[ans]
|
|
|
|
|
|
|
|
|
def temp_pyfile(src, ext='.py'):
|
|
|
"""Make a temporary python file, return filename and filehandle.
|
|
|
|
|
|
Parameters
|
|
|
----------
|
|
|
src : string or list of strings (no need for ending newlines if list)
|
|
|
Source code to be written to the file.
|
|
|
|
|
|
ext : optional, string
|
|
|
Extension for the generated file.
|
|
|
|
|
|
Returns
|
|
|
-------
|
|
|
(filename, open filehandle)
|
|
|
It is the caller's responsibility to close the open file and unlink it.
|
|
|
"""
|
|
|
fname = tempfile.mkstemp(ext)[1]
|
|
|
f = open(fname,'w')
|
|
|
f.write(src)
|
|
|
f.flush()
|
|
|
return fname, f
|
|
|
|
|
|
def _copy_metadata(src, dst):
|
|
|
"""Copy the set of metadata we want for atomic_writing.
|
|
|
|
|
|
Permission bits and flags. We'd like to copy file ownership as well, but we
|
|
|
can't do that.
|
|
|
"""
|
|
|
shutil.copymode(src, dst)
|
|
|
st = os.stat(src)
|
|
|
if hasattr(os, 'chflags') and hasattr(st, 'st_flags'):
|
|
|
os.chflags(st.st_flags)
|
|
|
|
|
|
@contextmanager
|
|
|
def atomic_writing(path, text=True, encoding='utf-8', **kwargs):
|
|
|
"""Context manager to write to a file only if the entire write is successful.
|
|
|
|
|
|
This works by creating a temporary file in the same directory, and renaming
|
|
|
it over the old file if the context is exited without an error. If the
|
|
|
target file is a symlink or a hardlink, this will not be preserved: it will
|
|
|
be replaced by a new regular file.
|
|
|
|
|
|
On Windows, there is a small chink in the atomicity: the target file is
|
|
|
deleted before renaming the temporary file over it. This appears to be
|
|
|
unavoidable.
|
|
|
|
|
|
Parameters
|
|
|
----------
|
|
|
path : str
|
|
|
The target file to write to.
|
|
|
|
|
|
text : bool, optional
|
|
|
Whether to open the file in text mode (i.e. to write unicode). Default is
|
|
|
True.
|
|
|
|
|
|
encoding : str, optional
|
|
|
The encoding to use for files opened in text mode. Default is UTF-8.
|
|
|
|
|
|
**kwargs
|
|
|
Passed to :func:`io.open`.
|
|
|
"""
|
|
|
path = os.path.realpath(path) # Dereference symlinks
|
|
|
dirname, basename = os.path.split(path)
|
|
|
handle, tmp_path = tempfile.mkstemp(prefix=basename, dir=dirname, text=text)
|
|
|
if text:
|
|
|
fileobj = io.open(handle, 'w', encoding=encoding, **kwargs)
|
|
|
else:
|
|
|
fileobj = io.open(handle, 'wb', **kwargs)
|
|
|
|
|
|
try:
|
|
|
yield fileobj
|
|
|
except:
|
|
|
fileobj.close()
|
|
|
os.remove(tmp_path)
|
|
|
raise
|
|
|
|
|
|
# Flush to disk
|
|
|
fileobj.flush()
|
|
|
os.fsync(fileobj.fileno())
|
|
|
|
|
|
# Written successfully, now rename it
|
|
|
fileobj.close()
|
|
|
|
|
|
# Copy permission bits, access time, etc.
|
|
|
try:
|
|
|
_copy_metadata(path, tmp_path)
|
|
|
except OSError:
|
|
|
# e.g. the file didn't already exist. Ignore any failure to copy metadata
|
|
|
pass
|
|
|
|
|
|
if os.name == 'nt' and os.path.exists(path):
|
|
|
# Rename over existing file doesn't work on Windows
|
|
|
os.remove(path)
|
|
|
|
|
|
os.rename(tmp_path, path)
|
|
|
|
|
|
|
|
|
def raw_print(*args, **kw):
|
|
|
"""Raw print to sys.__stdout__, otherwise identical interface to print()."""
|
|
|
|
|
|
print(*args, sep=kw.get('sep', ' '), end=kw.get('end', '\n'),
|
|
|
file=sys.__stdout__)
|
|
|
sys.__stdout__.flush()
|
|
|
|
|
|
|
|
|
def raw_print_err(*args, **kw):
|
|
|
"""Raw print to sys.__stderr__, otherwise identical interface to print()."""
|
|
|
|
|
|
print(*args, sep=kw.get('sep', ' '), end=kw.get('end', '\n'),
|
|
|
file=sys.__stderr__)
|
|
|
sys.__stderr__.flush()
|
|
|
|
|
|
|
|
|
# Short aliases for quick debugging, do NOT use these in production code.
|
|
|
rprint = raw_print
|
|
|
rprinte = raw_print_err
|
|
|
|
|
|
def unicode_std_stream(stream='stdout'):
|
|
|
u"""Get a wrapper to write unicode to stdout/stderr as UTF-8.
|
|
|
|
|
|
This ignores environment variables and default encodings, to reliably write
|
|
|
unicode to stdout or stderr.
|
|
|
|
|
|
::
|
|
|
|
|
|
unicode_std_stream().write(u'ł@e¶ŧ←')
|
|
|
"""
|
|
|
assert stream in ('stdout', 'stderr')
|
|
|
stream = getattr(sys, stream)
|
|
|
if PY3:
|
|
|
try:
|
|
|
stream_b = stream.buffer
|
|
|
except AttributeError:
|
|
|
# sys.stdout has been replaced - use it directly
|
|
|
return stream
|
|
|
else:
|
|
|
stream_b = stream
|
|
|
|
|
|
return codecs.getwriter('utf-8')(stream_b)
|
|
|
|
