"""Provides Tab completion when prompting users for a path."""
import glob
from types import TracebackType
from typing import Callable
from typing import Iterator
from typing import Optional
from typing import Type
from typing import TYPE_CHECKING
if TYPE_CHECKING:
from typing_extensions import Literal
# readline module is not available on all systems
try:
import readline
except ImportError:
import certbot._internal.display.dummy_readline as readline # type: ignore
class Completer:
"""Provides Tab completion when prompting users for a path.
This class is meant to be used with readline to provide Tab
completion for users entering paths. The complete method can be
passed to readline.set_completer directly, however, this function
works best as a context manager. For example:
with Completer():
raw_input()
In this example, Tab completion will be available during the call to
raw_input above, however, readline will be restored to its previous
state when exiting the body of the with statement.
"""
def __init__(self) -> None:
self._iter: Iterator[str]
self._original_completer: Optional[Callable]
self._original_delims: str
def complete(self, text: str, state: int) -> Optional[str]:
"""Provides path completion for use with readline.
:param str text: text to offer completions for
:param int state: which completion to return
:returns: possible completion for text or ``None`` if all
completions have been returned
:rtype: str
"""
if state == 0:
self._iter = glob.iglob(text + '*')
return next(self._iter, None)
def __enter__(self) -> None:
self._original_completer = readline.get_completer()
self._original_delims = readline.get_completer_delims()
readline.set_completer(self.complete)
readline.set_completer_delims(' \t\n;')
# readline can be implemented using GNU readline, pyreadline or libedit
# which have different configuration syntax
if readline.__doc__ is not None and 'libedit' in readline.__doc__:
readline.parse_and_bind('bind ^I rl_complete')
else:
readline.parse_and_bind('tab: complete')
def __exit__(self, unused_type: Optional[Type[BaseException]],
unused_value: Optional[BaseException],
unused_traceback: Optional[TracebackType]) -> 'Literal[False]':
readline.set_completer_delims(self._original_delims)
readline.set_completer(self._original_completer)
return False