Viewing file:  spawn.py (3.99 KB) -rw-r--r--
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"""distutils.spawn
Provides the 'spawn()' function, a front-end to various platform-
specific functions for launching another program in a sub-process.
"""
from __future__ import annotations
import os
import platform
import shutil
import subprocess
import sys
import warnings
from collections.abc import Mapping, MutableSequence
from typing import TYPE_CHECKING, TypeVar, overload
from ._log import log
from .debug import DEBUG
from .errors import DistutilsExecError
if TYPE_CHECKING:
from subprocess import _ENV
_MappingT = TypeVar("_MappingT", bound=Mapping)
def _debug(cmd):
"""
Render a subprocess command differently depending on DEBUG.
"""
return cmd if DEBUG else cmd[0]
def _inject_macos_ver(env: _MappingT | None) -> _MappingT | dict[str, str | int] | None:
if platform.system() != 'Darwin':
return env
from .util import MACOSX_VERSION_VAR, get_macosx_target_ver
target_ver = get_macosx_target_ver()
update = {MACOSX_VERSION_VAR: target_ver} if target_ver else {}
return {**_resolve(env), **update}
@overload
def _resolve(env: None) -> os._Environ[str]: ...
@overload
def _resolve(env: _MappingT) -> _MappingT: ...
def _resolve(env: _MappingT | None) -> _MappingT | os._Environ[str]:
return os.environ if env is None else env
def spawn(
cmd: MutableSequence[bytes | str | os.PathLike[str]],
search_path: bool = True,
verbose: bool = False,
dry_run: bool = False,
env: _ENV | None = None,
) -> None:
"""Run another program, specified as a command list 'cmd', in a new process.
'cmd' is just the argument list for the new process, ie.
cmd[0] is the program to run and cmd[1:] are the rest of its arguments.
There is no way to run a program with a name different from that of its
executable.
If 'search_path' is true (the default), the system's executable
search path will be used to find the program; otherwise, cmd[0]
must be the exact path to the executable. If 'dry_run' is true,
the command will not actually be run.
Raise DistutilsExecError if running the program fails in any way; just
return on success.
"""
log.info(subprocess.list2cmdline(cmd))
if dry_run:
return
if search_path:
executable = shutil.which(cmd[0])
if executable is not None:
cmd[0] = executable
try:
subprocess.check_call(cmd, env=_inject_macos_ver(env))
except OSError as exc:
raise DistutilsExecError(
f"command {_debug(cmd)!r} failed: {exc.args[-1]}"
) from exc
except subprocess.CalledProcessError as err:
raise DistutilsExecError(
f"command {_debug(cmd)!r} failed with exit code {err.returncode}"
) from err
def find_executable(executable: str, path: str | None = None) -> str | None:
"""Tries to find 'executable' in the directories listed in 'path'.
A string listing directories separated by 'os.pathsep'; defaults to
os.environ['PATH']. Returns the complete filename or None if not found.
"""
warnings.warn(
'Use shutil.which instead of find_executable', DeprecationWarning, stacklevel=2
)
_, ext = os.path.splitext(executable)
if (sys.platform == 'win32') and (ext != '.exe'):
executable = executable + '.exe'
if os.path.isfile(executable):
return executable
if path is None:
path = os.environ.get('PATH', None)
# bpo-35755: Don't fall through if PATH is the empty string
if path is None:
try:
path = os.confstr("CS_PATH")
except (AttributeError, ValueError):
# os.confstr() or CS_PATH is not available
path = os.defpath
# PATH='' doesn't match, whereas PATH=':' looks in the current directory
if not path:
return None
paths = path.split(os.pathsep)
for p in paths:
f = os.path.join(p, executable)
if os.path.isfile(f):
# the file exists, we have a shot at spawn working
return f
return None
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