import os
import re
import sys
import typing as t
from functools import update_wrapper
from types import ModuleType
from types import TracebackType
from ._compat import _default_text_stderr
from ._compat import _default_text_stdout
from ._compat import _find_binary_writer
from ._compat import auto_wrap_for_ansi
from ._compat import binary_streams
from ._compat import open_stream
from ._compat import should_strip_ansi
from ._compat import strip_ansi
from ._compat import text_streams
from ._compat import WIN
from .globals import resolve_color_default
if t.TYPE_CHECKING:
import typing_extensions as te
P = te.ParamSpec("P")
R = t.TypeVar("R")
def _posixify(name: str) -> str:
return "-".join(name.split()).lower()
def safecall(func: "t.Callable[P, R]") -> "t.Callable[P, t.Optional[R]]":
"""Wraps a function so that it swallows exceptions."""
def wrapper(*args: "P.args", **kwargs: "P.kwargs") -> t.Optional[R]:
try:
return func(*args, **kwargs)
except Exception:
pass
return None
return update_wrapper(wrapper, func)
def make_str(value: t.Any) -> str:
"""Converts a value into a valid string."""
if isinstance(value, bytes):
try:
return value.decode(sys.getfilesystemencoding())
except UnicodeError:
return value.decode("utf-8", "replace")
return str(value)
def make_default_short_help(help: str, max_length: int = 45) -> str:
"""Returns a condensed version of help string."""
# Consider only the first paragraph.
paragraph_end = help.find("\n\n")
if paragraph_end != -1:
help = help[:paragraph_end]
# Collapse newlines, tabs, and spaces.
words = help.split()
if not words:
return ""
# The first paragraph started with a "no rewrap" marker, ignore it.
if words[0] == "\b":
words = words[1:]
total_length = 0
last_index = len(words) - 1
for i, word in enumerate(words):
total_length += len(word) + (i > 0)
if total_length > max_length: # too long, truncate
break
if word[-1] == ".": # sentence end, truncate without "..."
return " ".join(words[: i + 1])
if total_length == max_length and i != last_index:
break # not at sentence end, truncate with "..."
else:
return " ".join(words) # no truncation needed
# Account for the length of the suffix.
total_length += len("...")
# remove words until the length is short enough
while i > 0:
total_length -= len(words[i]) + (i > 0)
if total_length <= max_length:
break
i -= 1
return " ".join(words[:i]) + "..."
class LazyFile:
"""A lazy file works like a regular file but it does not fully open
the file but it does perform some basic checks early to see if the
filename parameter does make sense. This is useful for safely opening
files for writing.
"""
def __init__(
self,
filename: t.Union[str, "os.PathLike[str]"],
mode: str = "r",
encoding: t.Optional[str] = None,
errors: t.Optional[str] = "strict",
atomic: bool = False,
):
self.name: str = os.fspath(filename)
self.mode = mode
self.encoding = encoding
self.errors = errors
self.atomic = atomic
self._f: t.Optional[t.IO[t.Any]]
self.should_close: bool
if self.name == "-":
self._f, self.should_close = open_stream(filename, mode, encoding, errors)
else:
if "r" in mode:
# Open and close the file in case we're opening it for
# reading so that we can catch at least some errors in
# some cases early.
open(filename, mode).close()
self._f = None
self.should_close = True
def __getattr__(self, name: str) -> t.Any:
return getattr(self.open(), name)
def __repr__(self) -> str:
if self._f is not None:
return repr(self._f)
return f"<unopened file '{format_filename(self.name)}' {self.mode}>"
def open(self) -> t.IO[t.Any]:
"""Opens the file if it's not yet open. This call might fail with
a :exc:`FileError`. Not handling this error will produce an error
that Click shows.
"""
if self._f is not None:
return self._f
try:
rv, self.should_close = open_stream(
self.name, self.mode, self.encoding, self.errors, atomic=self.atomic
)
except OSError as e: # noqa: E402
from .exceptions import FileError
raise FileError(self.name, hint=e.strerror) from e
self._f = rv
return rv
def close(self) -> None:
"""Closes the underlying file, no matter what."""
if self._f is not None:
self._f.close()
def close_intelligently(self) -> None:
"""This function only closes the file if it was opened by the lazy
file wrapper. For instance this will never close stdin.
"""
if self.should_close:
self.close()
def __enter__(self) -> "LazyFile":
return self
def __exit__(
self,
exc_type: t.Optional[t.Type[BaseException]],
exc_value: t.Optional[BaseException],
tb: t.Optional[TracebackType],
) -> None:
self.close_intelligently()
def __iter__(self) -> t.Iterator[t.AnyStr]:
self.open()
return iter(self._f) # type: ignore
class KeepOpenFile:
def __init__(self, file: t.IO[t.Any]) -> None:
self._file: t.IO[t.Any] = file
def __getattr__(self, name: str) -> t.Any:
return getattr(self._file, name)
def __enter__(self) -> "KeepOpenFile":
return self
def __exit__(
self,
exc_type: t.Optional[t.Type[BaseException]],
exc_value: t.Optional[BaseException],
tb: t.Optional[TracebackType],
) -> None:
pass
def __repr__(self) -> str:
return repr(self._file)
def __iter__(self) -> t.Iterator[t.AnyStr]:
return iter(self._file)
[docs]
def echo(
message: t.Optional[t.Any] = None,
file: t.Optional[t.IO[t.Any]] = None,
nl: bool = True,
err: bool = False,
color: t.Optional[bool] = None,
) -> None:
"""Print a message and newline to stdout or a file. This should be
used instead of :func:`print` because it provides better support
for different data, files, and environments.
Compared to :func:`print`, this does the following:
- Ensures that the output encoding is not misconfigured on Linux.
- Supports Unicode in the Windows console.
- Supports writing to binary outputs, and supports writing bytes
to text outputs.
- Supports colors and styles on Windows.
- Removes ANSI color and style codes if the output does not look
like an interactive terminal.
- Always flushes the output.
:param message: The string or bytes to output. Other objects are
converted to strings.
:param file: The file to write to. Defaults to ``stdout``.
:param err: Write to ``stderr`` instead of ``stdout``.
:param nl: Print a newline after the message. Enabled by default.
:param color: Force showing or hiding colors and other styles. By
default Click will remove color if the output does not look like
an interactive terminal.
.. versionchanged:: 6.0
Support Unicode output on the Windows console. Click does not
modify ``sys.stdout``, so ``sys.stdout.write()`` and ``print()``
will still not support Unicode.
.. versionchanged:: 4.0
Added the ``color`` parameter.
.. versionadded:: 3.0
Added the ``err`` parameter.
.. versionchanged:: 2.0
Support colors on Windows if colorama is installed.
"""
if file is None:
if err:
file = _default_text_stderr()
else:
file = _default_text_stdout()
# There are no standard streams attached to write to. For example,
# pythonw on Windows.
if file is None:
return
# Convert non bytes/text into the native string type.
if message is not None and not isinstance(message, (str, bytes, bytearray)):
out: t.Optional[t.Union[str, bytes]] = str(message)
else:
out = message
if nl:
out = out or ""
if isinstance(out, str):
out += "\n"
else:
out += b"\n"
if not out:
file.flush()
return
# If there is a message and the value looks like bytes, we manually
# need to find the binary stream and write the message in there.
# This is done separately so that most stream types will work as you
# would expect. Eg: you can write to StringIO for other cases.
if isinstance(out, (bytes, bytearray)):
binary_file = _find_binary_writer(file)
if binary_file is not None:
file.flush()
binary_file.write(out)
binary_file.flush()
return
# ANSI style code support. For no message or bytes, nothing happens.
# When outputting to a file instead of a terminal, strip codes.
else:
color = resolve_color_default(color)
if should_strip_ansi(file, color):
out = strip_ansi(out)
elif WIN:
if auto_wrap_for_ansi is not None:
file = auto_wrap_for_ansi(file) # type: ignore
elif not color:
out = strip_ansi(out)
file.write(out) # type: ignore
file.flush()
[docs]
def get_binary_stream(name: "te.Literal['stdin', 'stdout', 'stderr']") -> t.BinaryIO:
"""Returns a system stream for byte processing.
:param name: the name of the stream to open. Valid names are ``'stdin'``,
``'stdout'`` and ``'stderr'``
"""
opener = binary_streams.get(name)
if opener is None:
raise TypeError(f"Unknown standard stream '{name}'")
return opener()
[docs]
def get_text_stream(
name: "te.Literal['stdin', 'stdout', 'stderr']",
encoding: t.Optional[str] = None,
errors: t.Optional[str] = "strict",
) -> t.TextIO:
"""Returns a system stream for text processing. This usually returns
a wrapped stream around a binary stream returned from
:func:`get_binary_stream` but it also can take shortcuts for already
correctly configured streams.
:param name: the name of the stream to open. Valid names are ``'stdin'``,
``'stdout'`` and ``'stderr'``
:param encoding: overrides the detected default encoding.
:param errors: overrides the default error mode.
"""
opener = text_streams.get(name)
if opener is None:
raise TypeError(f"Unknown standard stream '{name}'")
return opener(encoding, errors)
[docs]
def open_file(
filename: str,
mode: str = "r",
encoding: t.Optional[str] = None,
errors: t.Optional[str] = "strict",
lazy: bool = False,
atomic: bool = False,
) -> t.IO[t.Any]:
"""Open a file, with extra behavior to handle ``'-'`` to indicate
a standard stream, lazy open on write, and atomic write. Similar to
the behavior of the :class:`~click.File` param type.
If ``'-'`` is given to open ``stdout`` or ``stdin``, the stream is
wrapped so that using it in a context manager will not close it.
This makes it possible to use the function without accidentally
closing a standard stream:
.. code-block:: python
with open_file(filename) as f:
...
:param filename: The name of the file to open, or ``'-'`` for
``stdin``/``stdout``.
:param mode: The mode in which to open the file.
:param encoding: The encoding to decode or encode a file opened in
text mode.
:param errors: The error handling mode.
:param lazy: Wait to open the file until it is accessed. For read
mode, the file is temporarily opened to raise access errors
early, then closed until it is read again.
:param atomic: Write to a temporary file and replace the given file
on close.
.. versionadded:: 3.0
"""
if lazy:
return t.cast(
t.IO[t.Any], LazyFile(filename, mode, encoding, errors, atomic=atomic)
)
f, should_close = open_stream(filename, mode, encoding, errors, atomic=atomic)
if not should_close:
f = t.cast(t.IO[t.Any], KeepOpenFile(f))
return f
[docs]
def get_app_dir(app_name: str, roaming: bool = True, force_posix: bool = False) -> str:
r"""Returns the config folder for the application. The default behavior
is to return whatever is most appropriate for the operating system.
To give you an idea, for an app called ``"Foo Bar"``, something like
the following folders could be returned:
Mac OS X:
``~/Library/Application Support/Foo Bar``
Mac OS X (POSIX):
``~/.foo-bar``
Unix:
``~/.config/foo-bar``
Unix (POSIX):
``~/.foo-bar``
Windows (roaming):
``C:\Users\<user>\AppData\Roaming\Foo Bar``
Windows (not roaming):
``C:\Users\<user>\AppData\Local\Foo Bar``
.. versionadded:: 2.0
:param app_name: the application name. This should be properly capitalized
and can contain whitespace.
:param roaming: controls if the folder should be roaming or not on Windows.
Has no effect otherwise.
:param force_posix: if this is set to `True` then on any POSIX system the
folder will be stored in the home folder with a leading
dot instead of the XDG config home or darwin's
application support folder.
"""
if WIN:
key = "APPDATA" if roaming else "LOCALAPPDATA"
folder = os.environ.get(key)
if folder is None:
folder = os.path.expanduser("~")
return os.path.join(folder, app_name)
if force_posix:
return os.path.join(os.path.expanduser(f"~/.{_posixify(app_name)}"))
if sys.platform == "darwin":
return os.path.join(
os.path.expanduser("~/Library/Application Support"), app_name
)
return os.path.join(
os.environ.get("XDG_CONFIG_HOME", os.path.expanduser("~/.config")),
_posixify(app_name),
)
class PacifyFlushWrapper:
"""This wrapper is used to catch and suppress BrokenPipeErrors resulting
from ``.flush()`` being called on broken pipe during the shutdown/final-GC
of the Python interpreter. Notably ``.flush()`` is always called on
``sys.stdout`` and ``sys.stderr``. So as to have minimal impact on any
other cleanup code, and the case where the underlying file is not a broken
pipe, all calls and attributes are proxied.
"""
def __init__(self, wrapped: t.IO[t.Any]) -> None:
self.wrapped = wrapped
def flush(self) -> None:
try:
self.wrapped.flush()
except OSError as e:
import errno
if e.errno != errno.EPIPE:
raise
def __getattr__(self, attr: str) -> t.Any:
return getattr(self.wrapped, attr)
def _detect_program_name(
path: t.Optional[str] = None, _main: t.Optional[ModuleType] = None
) -> str:
"""Determine the command used to run the program, for use in help
text. If a file or entry point was executed, the file name is
returned. If ``python -m`` was used to execute a module or package,
``python -m name`` is returned.
This doesn't try to be too precise, the goal is to give a concise
name for help text. Files are only shown as their name without the
path. ``python`` is only shown for modules, and the full path to
``sys.executable`` is not shown.
:param path: The Python file being executed. Python puts this in
``sys.argv[0]``, which is used by default.
:param _main: The ``__main__`` module. This should only be passed
during internal testing.
.. versionadded:: 8.0
Based on command args detection in the Werkzeug reloader.
:meta private:
"""
if _main is None:
_main = sys.modules["__main__"]
if not path:
path = sys.argv[0]
# The value of __package__ indicates how Python was called. It may
# not exist if a setuptools script is installed as an egg. It may be
# set incorrectly for entry points created with pip on Windows.
# It is set to "" inside a Shiv or PEX zipapp.
if getattr(_main, "__package__", None) in {None, ""} or (
os.name == "nt"
and _main.__package__ == ""
and not os.path.exists(path)
and os.path.exists(f"{path}.exe")
):
# Executed a file, like "python app.py".
return os.path.basename(path)
# Executed a module, like "python -m example".
# Rewritten by Python from "-m script" to "/path/to/script.py".
# Need to look at main module to determine how it was executed.
py_module = t.cast(str, _main.__package__)
name = os.path.splitext(os.path.basename(path))[0]
# A submodule like "example.cli".
if name != "__main__":
py_module = f"{py_module}.{name}"
return f"python -m {py_module.lstrip('.')}"
def _expand_args(
args: t.Iterable[str],
*,
user: bool = True,
env: bool = True,
glob_recursive: bool = True,
) -> t.List[str]:
"""Simulate Unix shell expansion with Python functions.
See :func:`glob.glob`, :func:`os.path.expanduser`, and
:func:`os.path.expandvars`.
This is intended for use on Windows, where the shell does not do any
expansion. It may not exactly match what a Unix shell would do.
:param args: List of command line arguments to expand.
:param user: Expand user home directory.
:param env: Expand environment variables.
:param glob_recursive: ``**`` matches directories recursively.
.. versionchanged:: 8.1
Invalid glob patterns are treated as empty expansions rather
than raising an error.
.. versionadded:: 8.0
:meta private:
"""
from glob import glob
out = []
for arg in args:
if user:
arg = os.path.expanduser(arg)
if env:
arg = os.path.expandvars(arg)
try:
matches = glob(arg, recursive=glob_recursive)
except re.error:
matches = []
if not matches:
out.append(arg)
else:
out.extend(matches)
return out