Source code for xonsh.shell

# -*- coding: utf-8 -*-
"""The xonsh shell"""
import os
import random
import builtins
import warnings

from xonsh.xontribs import update_context
from xonsh.environ import xonshrc_context
from xonsh.execer import Execer
from xonsh.platform import (best_shell_type, has_prompt_toolkit,
                            ptk_version_is_supported)
from xonsh.tools import XonshError, to_bool_or_int


[docs]class Shell(object): """Main xonsh shell. Initializes execution environment and decides if prompt_toolkit or readline version of shell should be used. """ def __init__(self, ctx=None, shell_type=None, config=None, rc=None, **kwargs): """ Parameters ---------- ctx : Mapping, optional The execution context for the shell (e.g. the globals namespace). If none, this is computed by loading the rc files. If not None, this no additional context is computed and this is used directly. shell_type : str, optional The shell type to start, such as 'readline', 'prompt_toolkit', or 'random'. config : str, optional Path to configuration file. rc : list of str, optional Sequence of paths to run control files. """ self.login = kwargs.get('login', True) self.stype = shell_type self._init_environ(ctx, config, rc, kwargs.get('scriptcache', True), kwargs.get('cacheall', False)) env = builtins.__xonsh_env__ # pick a valid shell -- if no shell is specified by the user, # shell type is pulled from env if shell_type is None: shell_type = env.get('SHELL_TYPE') if shell_type == 'best' or shell_type is None: shell_type = best_shell_type() elif shell_type == 'random': shell_type = random.choice(('readline', 'prompt_toolkit')) if shell_type == 'prompt_toolkit': if not has_prompt_toolkit(): warnings.warn('prompt_toolkit is not available, using ' 'readline instead.') shell_type = 'readline' elif not ptk_version_is_supported(): warnings.warn('prompt-toolkit version < v1.0.0 is not ' 'supported. Please update prompt-toolkit. Using ' 'readline instead.') shell_type = 'readline' env['SHELL_TYPE'] = shell_type # actually make the shell if shell_type == 'none': from xonsh.base_shell import BaseShell as shell_class elif shell_type == 'prompt_toolkit': from xonsh.ptk.shell import PromptToolkitShell as shell_class elif shell_type == 'readline': from xonsh.readline_shell import ReadlineShell as shell_class else: raise XonshError('{} is not recognized as a shell type'.format( shell_type)) self.shell = shell_class(execer=self.execer, ctx=self.ctx, **kwargs) # allows history garbace colector to start running builtins.__xonsh_history__.gc.wait_for_shell = False def __getattr__(self, attr): """Delegates calls to appropriate shell instance.""" return getattr(self.shell, attr) def _init_environ(self, ctx, config, rc, scriptcache, cacheall): self.ctx = {} if ctx is None else ctx debug = to_bool_or_int(os.getenv('XONSH_DEBUG', '0')) self.execer = Execer(config=config, login=self.login, xonsh_ctx=self.ctx, debug_level=debug) self.execer.scriptcache = scriptcache self.execer.cacheall = cacheall if self.stype != 'none' or self.login: # load xontribs from config file names = builtins.__xonsh_config__.get('xontribs', ()) for name in names: update_context(name, ctx=self.ctx) # load run control files env = builtins.__xonsh_env__ rc = env.get('XONSHRC') if rc is None else rc self.ctx.update(xonshrc_context(rcfiles=rc, execer=self.execer, initial=self.ctx)) self.ctx['__name__'] = '__main__'