Module materialize.spawn
Utilities for spawning processes.
The functions in this module are a convenient high-level interface to the
operations provided by the standard subprocess
module.
Expand source code Browse git
# Copyright Materialize, Inc. and contributors. All rights reserved.
#
# Use of this software is governed by the Business Source License
# included in the LICENSE file at the root of this repository.
#
# As of the Change Date specified in that file, in accordance with
# the Business Source License, use of this software will be governed
# by the Apache License, Version 2.0.
"""Utilities for spawning processes.
The functions in this module are a convenient high-level interface to the
operations provided by the standard [`subprocess`][subprocess] module.
[subprocess]: https://docs.python.org/3/library/subprocess.html
"""
import subprocess
import sys
from collections.abc import Sequence
from pathlib import Path
from typing import IO
from materialize import ui
CalledProcessError = subprocess.CalledProcessError
# NOTE(benesch): Please think twice before adding additional parameters to this
# method! It is meant to serve 95% of callers with a small ands understandable
# set of parameters. If your needs are niche, consider calling `subprocess.run`
# directly rather than adding a one-off parameter here.
def runv(
args: Sequence[Path | str],
*,
cwd: Path | None = None,
env: dict[str, str] | None = None,
stdin: None | int | IO[bytes] | bytes = None,
stdout: None | int | IO[bytes] = None,
stderr: None | int | IO[bytes] = None,
) -> subprocess.CompletedProcess:
"""Verbosely run a subprocess.
A description of the subprocess will be written to stdout before the
subprocess is executed.
Args:
args: A list of strings or paths describing the program to run and
the arguments to pass to it.
cwd: An optional directory to change into before executing the process.
env: A replacement environment with which to launch the process. If
unspecified, the current process's environment is used. Replacement
occurs wholesale, so use a construction like
`env=dict(os.environ, KEY=VAL, ...)` to instead amend the existing
environment.
stdin: An optional IO handle or byte string to use as the process's
stdin stream.
stdout: An optional IO handle to use as the process's stdout stream.
stderr: An optional IO handle to use as the process's stderr stream.
Raises:
OSError: The process cannot be executed, e.g. because the specified
program does not exist.
CalledProcessError: The process exited with a non-zero exit status.
"""
print("$", ui.shell_quote(args), file=sys.stderr)
input = None
if isinstance(stdin, bytes):
input = stdin
stdin = None
return subprocess.run(
args,
cwd=cwd,
env=env,
input=input,
stdin=stdin,
stdout=stdout,
stderr=stderr,
check=True,
)
def capture(
args: Sequence[Path | str],
*,
cwd: Path | None = None,
env: dict[str, str] | None = None,
stdin: None | int | IO[bytes] | str = None,
stderr: None | int | IO[bytes] = None,
) -> str:
"""Capture the output of a subprocess.
Args:
args: A list of strings or paths describing the program to run and
the arguments to pass to it.
cwd: An optional directory to change into before executing the process.
env: A replacement environment with which to launch the process. If
unspecified, the current process's environment is used. Replacement
occurs wholesale, so use a construction like
`env=dict(os.environ, KEY=VAL, ...)` to instead amend the existing
environment.
stdin: An optional IO handle, byte string or string to use as the process's
stdin stream.
stderr: An optional IO handle to use as the process's stderr stream.
Returns:
output: The verbatim output of the process as a string. Note that
trailing whitespace is preserved.
Raises:
OSError: The process cannot be executed, e.g. because the specified
program does not exist.
CalledProcessError: The process exited with a non-zero exit status.
.. tip:: Many programs produce output with a trailing newline.
You may want to call `strip()` on the output to remove any trailing
whitespace.
"""
input = None
if isinstance(stdin, str):
input = stdin
stdin = None
return subprocess.check_output(
args, cwd=cwd, env=env, input=input, stdin=stdin, stderr=stderr, text=True
)
def run_and_get_return_code(
args: Sequence[Path | str],
*,
cwd: Path | None = None,
env: dict[str, str] | None = None,
) -> int:
"""Run a subprocess and return the return code."""
try:
capture(args, cwd=cwd, env=env, stderr=subprocess.DEVNULL)
return 0
except CalledProcessError as e:
return e.returncode
Functions
def capture(args: collections.abc.Sequence[pathlib.Path | str], *, cwd: pathlib.Path | None = None, env: dict[str, str] | None = None, stdin: Union[ForwardRef(None), int, IO[bytes], str] = None, stderr: Union[ForwardRef(None), int, IO[bytes]] = None) ‑> str
-
Capture the output of a subprocess.
Args
args
- A list of strings or paths describing the program to run and the arguments to pass to it.
cwd
- An optional directory to change into before executing the process.
env
- A replacement environment with which to launch the process. If
unspecified, the current process's environment is used. Replacement
occurs wholesale, so use a construction like
env=dict(os.environ, KEY=VAL, ...)
to instead amend the existing environment. stdin
- An optional IO handle, byte string or string to use as the process's stdin stream.
stderr
- An optional IO handle to use as the process's stderr stream.
Returns
output
- The verbatim output of the process as a string. Note that trailing whitespace is preserved.
Raises
OSError
- The process cannot be executed, e.g. because the specified program does not exist.
CalledProcessError
- The process exited with a non-zero exit status.
Tip: Many programs produce output with a trailing newline.
You may want to call
strip()
on the output to remove any trailing whitespace.Expand source code Browse git
def capture( args: Sequence[Path | str], *, cwd: Path | None = None, env: dict[str, str] | None = None, stdin: None | int | IO[bytes] | str = None, stderr: None | int | IO[bytes] = None, ) -> str: """Capture the output of a subprocess. Args: args: A list of strings or paths describing the program to run and the arguments to pass to it. cwd: An optional directory to change into before executing the process. env: A replacement environment with which to launch the process. If unspecified, the current process's environment is used. Replacement occurs wholesale, so use a construction like `env=dict(os.environ, KEY=VAL, ...)` to instead amend the existing environment. stdin: An optional IO handle, byte string or string to use as the process's stdin stream. stderr: An optional IO handle to use as the process's stderr stream. Returns: output: The verbatim output of the process as a string. Note that trailing whitespace is preserved. Raises: OSError: The process cannot be executed, e.g. because the specified program does not exist. CalledProcessError: The process exited with a non-zero exit status. .. tip:: Many programs produce output with a trailing newline. You may want to call `strip()` on the output to remove any trailing whitespace. """ input = None if isinstance(stdin, str): input = stdin stdin = None return subprocess.check_output( args, cwd=cwd, env=env, input=input, stdin=stdin, stderr=stderr, text=True )
def run_and_get_return_code(args: collections.abc.Sequence[pathlib.Path | str], *, cwd: pathlib.Path | None = None, env: dict[str, str] | None = None) ‑> int
-
Run a subprocess and return the return code.
Expand source code Browse git
def run_and_get_return_code( args: Sequence[Path | str], *, cwd: Path | None = None, env: dict[str, str] | None = None, ) -> int: """Run a subprocess and return the return code.""" try: capture(args, cwd=cwd, env=env, stderr=subprocess.DEVNULL) return 0 except CalledProcessError as e: return e.returncode
def runv(args: collections.abc.Sequence[pathlib.Path | str], *, cwd: pathlib.Path | None = None, env: dict[str, str] | None = None, stdin: Union[ForwardRef(None), int, IO[bytes], bytes] = None, stdout: Union[ForwardRef(None), int, IO[bytes]] = None, stderr: Union[ForwardRef(None), int, IO[bytes]] = None) ‑> subprocess.CompletedProcess
-
Verbosely run a subprocess.
A description of the subprocess will be written to stdout before the subprocess is executed.
Args
args
- A list of strings or paths describing the program to run and the arguments to pass to it.
cwd
- An optional directory to change into before executing the process.
env
- A replacement environment with which to launch the process. If
unspecified, the current process's environment is used. Replacement
occurs wholesale, so use a construction like
env=dict(os.environ, KEY=VAL, ...)
to instead amend the existing environment. stdin
- An optional IO handle or byte string to use as the process's stdin stream.
stdout
- An optional IO handle to use as the process's stdout stream.
stderr
- An optional IO handle to use as the process's stderr stream.
Raises
OSError
- The process cannot be executed, e.g. because the specified program does not exist.
CalledProcessError
- The process exited with a non-zero exit status.
Expand source code Browse git
def runv( args: Sequence[Path | str], *, cwd: Path | None = None, env: dict[str, str] | None = None, stdin: None | int | IO[bytes] | bytes = None, stdout: None | int | IO[bytes] = None, stderr: None | int | IO[bytes] = None, ) -> subprocess.CompletedProcess: """Verbosely run a subprocess. A description of the subprocess will be written to stdout before the subprocess is executed. Args: args: A list of strings or paths describing the program to run and the arguments to pass to it. cwd: An optional directory to change into before executing the process. env: A replacement environment with which to launch the process. If unspecified, the current process's environment is used. Replacement occurs wholesale, so use a construction like `env=dict(os.environ, KEY=VAL, ...)` to instead amend the existing environment. stdin: An optional IO handle or byte string to use as the process's stdin stream. stdout: An optional IO handle to use as the process's stdout stream. stderr: An optional IO handle to use as the process's stderr stream. Raises: OSError: The process cannot be executed, e.g. because the specified program does not exist. CalledProcessError: The process exited with a non-zero exit status. """ print("$", ui.shell_quote(args), file=sys.stderr) input = None if isinstance(stdin, bytes): input = stdin stdin = None return subprocess.run( args, cwd=cwd, env=env, input=input, stdin=stdin, stdout=stdout, stderr=stderr, check=True, )