xonsh/xonsh/base_shell.py
2017-12-07 18:34:09 -05:00

554 lines
20 KiB
Python

# -*- coding: utf-8 -*-
"""The base class for xonsh shell"""
import io
import os
import sys
import time
import builtins
from xonsh.tools import (XonshError, print_exception, DefaultNotGiven,
check_for_partial_string, format_std_prepost,
get_line_continuation)
from xonsh.platform import HAS_PYGMENTS, ON_WINDOWS
from xonsh.codecache import (should_use_cache, code_cache_name,
code_cache_check, get_cache_filename,
update_cache, run_compiled_code)
from xonsh.completer import Completer
from xonsh.prompt.base import multiline_prompt, PromptFormatter
from xonsh.events import events
from xonsh.shell import transform_command
from xonsh.lazyimps import pygments, pyghooks
from xonsh.ansi_colors import ansi_partial_color_format
if ON_WINDOWS:
import ctypes
kernel32 = ctypes.windll.kernel32
kernel32.SetConsoleTitleW.argtypes = [ctypes.c_wchar_p]
class _TeeStdBuf(io.RawIOBase):
"""A dispatcher for bytes to two buffers, as std stream buffer and an
in memory buffer.
"""
def __init__(self, stdbuf, membuf, encoding=None, errors=None, prestd=b'',
poststd=b''):
"""
Parameters
----------
stdbuf : BytesIO-like or StringIO-like
The std stream buffer.
membuf : BytesIO-like
The in memory stream buffer.
encoding : str or None, optional
The encoding of the stream. Only used if stdbuf is a text stream,
rather than a binary one. Defaults to $XONSH_ENCODING if None.
errors : str or None, optional
The error form for the encoding of the stream. Only used if stdbuf
is a text stream, rather than a binary one. Deafults to
$XONSH_ENCODING_ERRORS if None.
prestd : bytes, optional
The prefix to prepend to the standard buffer.
poststd : bytes, optional
The postfix to append to the standard buffer.
"""
self.stdbuf = stdbuf
self.membuf = membuf
env = builtins.__xonsh_env__
self.encoding = env.get('XONSH_ENCODING') if encoding is None else encoding
self.errors = env.get('XONSH_ENCODING_ERRORS') if errors is None else errors
self.prestd = prestd
self.poststd = poststd
self._std_is_binary = not hasattr(stdbuf, 'encoding')
def fileno(self):
"""Returns the file descriptor of the std buffer."""
return self.stdbuf.fileno()
def seek(self, offset, whence=io.SEEK_SET):
"""Sets the location in both the stdbuf and the membuf."""
self.stdbuf.seek(offset, whence)
self.membuf.seek(offset, whence)
def truncate(self, size=None):
"""Truncate both buffers."""
self.stdbuf.truncate(size)
self.membuf.truncate(size)
def readinto(self, b):
"""Read bytes into buffer from both streams."""
if self._std_is_binary:
self.stdbuf.readinto(b)
return self.membuf.readinto(b)
def write(self, b):
"""Write bytes into both buffers."""
std_b = b
if self.prestd:
std_b = self.prestd + b
if self.poststd:
std_b += self.poststd
# write to stdbuf
if self._std_is_binary:
self.stdbuf.write(std_b)
else:
self.stdbuf.write(std_b.decode(encoding=self.encoding,
errors=self.errors))
return self.membuf.write(b)
class _TeeStd(io.TextIOBase):
"""Tees a std stream into an in-memory container and the original stream."""
def __init__(self, name, mem, prestd='', poststd=''):
"""
Parameters
----------
name : str
The name of the buffer in the sys module, e.g. 'stdout'.
mem : io.TextIOBase-like
The in-memory text-based representation.
prestd : str, optional
The prefix to prepend to the standard stream.
poststd : str, optional
The postfix to append to the standard stream.
"""
self._name = name
self.std = std = getattr(sys, name)
self.mem = mem
self.prestd = prestd
self.poststd = poststd
preb = prestd.encode(encoding=mem.encoding, errors=mem.errors)
postb = poststd.encode(encoding=mem.encoding, errors=mem.errors)
if hasattr(std, 'buffer'):
buffer = _TeeStdBuf(std.buffer, mem.buffer,
prestd=preb, poststd=postb)
else:
# TextIO does not have buffer as part of the API, so std streams
# may not either.
buffer = _TeeStdBuf(std, mem.buffer, encoding=mem.encoding,
errors=mem.errors, prestd=preb, poststd=postb)
self.buffer = buffer
setattr(sys, name, self)
@property
def encoding(self):
"""The encoding of the in-memory buffer."""
return self.mem.encoding
@property
def errors(self):
"""The errors of the in-memory buffer."""
return self.mem.errors
@property
def newlines(self):
"""The newlines of the in-memory buffer."""
return self.mem.newlines
def _replace_std(self):
std = self.std
if std is None:
return
setattr(sys, self._name, std)
self.std = self._name = None
def __del__(self):
self._replace_std()
def close(self):
"""Restores the original std stream."""
self._replace_std()
def write(self, s):
"""Writes data to the original std stream and the in-memory object."""
self.mem.write(s)
if self.std is None:
return
std_s = s
if self.prestd:
std_s = self.prestd + std_s
if self.poststd:
std_s += self.poststd
self.std.write(std_s)
def flush(self):
"""Flushes both the original stdout and the buffer."""
self.std.flush()
self.mem.flush()
def fileno(self):
"""Tunnel fileno() calls to the std stream."""
return self.std.fileno()
def seek(self, offset, whence=io.SEEK_SET):
"""Seek to a location in both streams."""
self.std.seek(offset, whence)
self.mem.seek(offset, whence)
def truncate(self, size=None):
"""Seek to a location in both streams."""
self.std.truncate(size)
self.mem.truncate(size)
def detach(self):
"""This operation is not supported."""
raise io.UnsupportedOperation
def read(self, size=None):
"""Read from the in-memory stream and seek to a new location in the
std stream.
"""
s = self.mem.read(size)
loc = self.std.tell()
self.std.seek(loc + len(s))
return s
def readline(self, size=-1):
"""Read a line from the in-memory stream and seek to a new location
in the std stream.
"""
s = self.mem.readline(size)
loc = self.std.tell()
self.std.seek(loc + len(s))
return s
class Tee:
"""Class that merges tee'd stdout and stderr into a single stream.
This represents what a user would actually see on the command line.
This class has the same interface as io.TextIOWrapper, except that
the buffer is optional.
"""
# pylint is a stupid about counting public methods when using inheritance.
# pylint: disable=too-few-public-methods
def __init__(self, buffer=None, encoding=None, errors=None,
newline=None, line_buffering=False, write_through=False):
self.buffer = io.BytesIO() if buffer is None else buffer
self.memory = io.TextIOWrapper(self.buffer, encoding=encoding,
errors=errors, newline=newline,
line_buffering=line_buffering,
write_through=write_through)
self.stdout = _TeeStd('stdout', self.memory)
env = builtins.__xonsh_env__
prestderr = format_std_prepost(env.get('XONSH_STDERR_PREFIX'))
poststderr = format_std_prepost(env.get('XONSH_STDERR_POSTFIX'))
self.stderr = _TeeStd('stderr', self.memory, prestd=prestderr,
poststd=poststderr)
@property
def line_buffering(self):
return self.memory.line_buffering
def __del__(self):
del self.stdout, self.stderr
self.stdout = self.stderr = None
def close(self):
"""Closes the buffer as well as the stdout and stderr tees."""
self.stdout.close()
self.stderr.close()
self.memory.close()
def getvalue(self):
"""Gets the current contents of the in-memory buffer."""
m = self.memory
loc = m.tell()
m.seek(0)
s = m.read()
m.seek(loc)
return s
class BaseShell(object):
"""The xonsh shell."""
def __init__(self, execer, ctx, **kwargs):
super().__init__()
self.execer = execer
self.ctx = ctx
self.completer = Completer() if kwargs.get('completer', True) else None
self.buffer = []
self.need_more_lines = False
self.mlprompt = None
self._styler = DefaultNotGiven
self.prompt_formatter = PromptFormatter()
self.accumulated_inputs = ''
@property
def styler(self):
if self._styler is DefaultNotGiven:
if HAS_PYGMENTS:
from xonsh.pyghooks import XonshStyle
env = builtins.__xonsh_env__
self._styler = XonshStyle(env.get('XONSH_COLOR_STYLE'))
else:
self._styler = None
return self._styler
@styler.setter
def styler(self, value):
self._styler = value
@styler.deleter
def styler(self):
self._styler = DefaultNotGiven
def emptyline(self):
"""Called when an empty line has been entered."""
self.need_more_lines = False
self.default('')
def singleline(self, **kwargs):
"""Reads a single line of input from the shell."""
msg = '{0} has not implemented singleline().'
raise RuntimeError(msg.format(self.__class__.__name__))
def precmd(self, line):
"""Called just before execution of line."""
return line if self.need_more_lines else line.lstrip()
def default(self, line):
"""Implements code execution."""
line = line if line.endswith('\n') else line + '\n'
src, code = self.push(line)
if code is None:
return
events.on_precommand.fire(cmd=src)
env = builtins.__xonsh_env__
hist = builtins.__xonsh_history__ # pylint: disable=no-member
ts1 = None
enc = env.get('XONSH_ENCODING')
err = env.get('XONSH_ENCODING_ERRORS')
tee = Tee(encoding=enc, errors=err)
try:
ts0 = time.time()
run_compiled_code(code, self.ctx, None, 'single')
ts1 = time.time()
if hist is not None and hist.last_cmd_rtn is None:
hist.last_cmd_rtn = 0 # returncode for success
except XonshError as e:
print(e.args[0], file=sys.stderr)
if hist is not None and hist.last_cmd_rtn is None:
hist.last_cmd_rtn = 1 # return code for failure
except Exception: # pylint: disable=broad-except
print_exception()
if hist is not None and hist.last_cmd_rtn is None:
hist.last_cmd_rtn = 1 # return code for failure
finally:
ts1 = ts1 or time.time()
tee_out = tee.getvalue()
self._append_history(inp=src, ts=[ts0, ts1], tee_out=tee_out)
self.accumulated_inputs += src
append_newline = env.get('XONSH_APPEND_NEWLINE')
if append_newline and not tee_out.endswith(os.linesep):
print(os.linesep, end='')
tee.close()
self._fix_cwd()
if builtins.__xonsh_exit__: # pylint: disable=no-member
return True
def _append_history(self, tee_out=None, **info):
"""Append information about the command to the history.
This also handles on_postcommand because this is the place where all the
information is available.
"""
hist = builtins.__xonsh_history__ # pylint: disable=no-member
info['rtn'] = hist.last_cmd_rtn if hist is not None else None
tee_out = tee_out or None
last_out = hist.last_cmd_out if hist is not None else None
if last_out is None and tee_out is None:
pass
elif last_out is None and tee_out is not None:
info['out'] = tee_out
elif last_out is not None and tee_out is None:
info['out'] = last_out
else:
info['out'] = tee_out + '\n' + last_out
events.on_postcommand.fire(
cmd=info['inp'],
rtn=info['rtn'],
out=info.get('out', None),
ts=info['ts']
)
if hist is not None:
hist.append(info)
hist.last_cmd_rtn = hist.last_cmd_out = None
def _fix_cwd(self):
"""Check if the cwd changed out from under us."""
env = builtins.__xonsh_env__
try:
cwd = os.getcwd()
except (FileNotFoundError, OSError):
cwd = None
if cwd is None:
# directory has been deleted out from under us, most likely
pwd = env.get('PWD', None)
if pwd is None:
# we have no idea where we are
env['PWD'] = '<invalid directory>'
elif os.path.isdir(pwd):
# unclear why os.getcwd() failed. do nothing.
pass
else:
# OK PWD is really gone.
msg = '{UNDERLINE_INTENSE_WHITE}{BACKGROUND_INTENSE_BLACK}'
msg += "xonsh: working directory does not exist: " + pwd
msg += '{NO_COLOR}'
self.print_color(msg, file=sys.stderr)
elif 'PWD' not in env:
# $PWD is missing from env, recreate it
env['PWD'] = cwd
elif os.path.realpath(cwd) != os.path.realpath(env['PWD']):
# The working directory has changed without updating $PWD, fix this
old = env['PWD']
env['PWD'] = cwd
env['OLDPWD'] = old
events.on_chdir.fire(olddir=old, newdir=cwd)
def push(self, line):
"""Pushes a line onto the buffer and compiles the code in a way that
enables multiline input.
"""
self.buffer.append(line)
if self.need_more_lines:
return None, None
src = ''.join(self.buffer)
src = transform_command(src)
return self.compile(src)
def compile(self, src):
"""Compiles source code and returns the (possibly modified) source and
a valid code object.
"""
_cache = should_use_cache(self.execer, 'single')
if _cache:
codefname = code_cache_name(src)
cachefname = get_cache_filename(codefname, code=True)
usecache, code = code_cache_check(cachefname)
if usecache:
self.reset_buffer()
return src, code
lincont = get_line_continuation()
if src.endswith(lincont+'\n'):
self.need_more_lines = True
return src, None
try:
code = self.execer.compile(src,
mode='single',
glbs=self.ctx,
locs=None)
if _cache:
update_cache(code, cachefname)
self.reset_buffer()
except SyntaxError:
partial_string_info = check_for_partial_string(src)
in_partial_string = (partial_string_info[0] is not None and
partial_string_info[1] is None)
if (src == '\n' or src.endswith('\n\n')) and not in_partial_string:
self.reset_buffer()
print_exception()
return src, None
self.need_more_lines = True
code = None
except Exception: # pylint: disable=broad-except
self.reset_buffer()
print_exception()
code = None
return src, code
def reset_buffer(self):
"""Resets the line buffer."""
self.buffer.clear()
self.need_more_lines = False
self.mlprompt = None
def settitle(self):
"""Sets terminal title."""
env = builtins.__xonsh_env__ # pylint: disable=no-member
term = env.get('TERM', None)
# Shells running in emacs sets TERM to "dumb" or "eterm-color".
# Do not set title for these to avoid garbled prompt.
if (term is None and not ON_WINDOWS) or term in ['dumb', 'eterm-color',
'linux']:
return
t = env.get('TITLE')
if t is None:
return
t = self.prompt_formatter(t)
if ON_WINDOWS and 'ANSICON' not in env:
kernel32.SetConsoleTitleW(t)
else:
with open(1, 'wb', closefd=False) as f:
# prevent xonsh from answering interactive questions
# on the next command by writing the title
f.write("\x1b]0;{0}\x07".format(t).encode())
f.flush()
@property
def prompt(self):
"""Obtains the current prompt string."""
if self.need_more_lines:
if self.mlprompt is None:
try:
self.mlprompt = multiline_prompt()
except Exception: # pylint: disable=broad-except
print_exception()
self.mlprompt = '<multiline prompt error> '
return self.mlprompt
env = builtins.__xonsh_env__ # pylint: disable=no-member
p = env.get('PROMPT')
try:
p = self.prompt_formatter(p)
except Exception: # pylint: disable=broad-except
print_exception()
self.settitle()
return p
def format_color(self, string, hide=False, force_string=False, **kwargs):
"""Formats the colors in a string. ``BaseShell``'s default implementation
of this method uses colors based on ANSI color codes.
"""
style = builtins.__xonsh_env__.get('XONSH_COLOR_STYLE')
return ansi_partial_color_format(string, hide=hide, style=style)
def print_color(self, string, hide=False, **kwargs):
"""Prints a string in color. This base implementation's colors are based
on ANSI color codes if a string was given as input. If a list of token
pairs is given, it will color based on pygments, if available. If
pygments is not available, it will print a colorless string.
"""
if isinstance(string, str):
s = self.format_color(string, hide=hide)
elif HAS_PYGMENTS:
# assume this is a list of (Token, str) tuples and format it
env = builtins.__xonsh_env__
self.styler.style_name = env.get('XONSH_COLOR_STYLE')
style_proxy = pyghooks.xonsh_style_proxy(self.styler)
formatter = pyghooks.XonshTerminal256Formatter(style=style_proxy)
s = pygments.format(string, formatter).rstrip()
else:
# assume this is a list of (Token, str) tuples and remove color
s = ''.join([x for _, x in string])
print(s, **kwargs)
def color_style_names(self):
"""Returns an iterable of all available style names."""
return ()
def color_style(self):
"""Returns the current color map."""
return {}
def restore_tty_sanity(self):
"""An interface for resetting the TTY stdin mode. This is highly
dependent on the shell backend. Also it is mostly optional since
it only affects ^Z backgrounding behaviour.
"""
pass