Files
bake/bashf/bash.py
T
2019-09-15 07:03:27 -04:00

111 lines
3.0 KiB
Python

"""
bash.py module
"""
import re
import time
import json as json_lib
from shlex import quote as shlex_quote
import delegator
DELEGATOR_MINIMUM_TIMEOUT = 60 * 60 * 60 * 8
WHICH_BASH = "bash"
# Monkey-patch delegator (hack):
if delegator.TIMEOUT < DELEGATOR_MINIMUM_TIMEOUT:
delegator.TIMEOUT = DELEGATOR_MINIMUM_TIMEOUT
__all__ = ["run", "Bash"]
class BashProcess:
"""Bash process object."""
def __init__(self, args, parent: "Bash", blocking: bool = True) -> None:
"""constructor"""
# Environ inherents from parent.
# Remember passed-in arguments.
self.parent = parent
self.args = args
# Run the subprocess.
args = " ".join(args)
self.start_time = time.time()
self.sub = delegator.run(
f"{self.parent.path} {args}",
env=self.parent.environ,
block=blocking,
)
if blocking:
self.elapsed_time = time.time() - self.start_time
@property
def output(self) -> str:
"""stdout of the running process"""
return str(self.sub.out)
@property
def err(self) -> str:
"""stderr of the running process"""
return str(self.sub.err)
@property
def json(self) -> dict:
"""stdout of the running process, converted to a dict if it's json"""
return json_lib.loads(str(self.sub.out))
@property
def ok(self) -> bool:
"""if the process exited with a 0 exit code"""
return self.sub.ok
@property
def return_code(self) -> int:
"""the exit code of the process"""
return self.sub.return_code
@property
def pid(self) -> int:
"""the process id"""
return self.sub.pid
def __repr__(self) -> str:
"""string representation of the bash process"""
return f"<BashProcess pid={self.sub.pid!r} return_code={self.sub.return_code!r}>"
class Bash:
"""An instance of Bash."""
def __init__(self, *, path=WHICH_BASH, environ=None, interactive=False):
"""constructor"""
self.path = path
self.interactive = interactive
self.environ = environ or {}
ver_proc = self._exec("--version")
if not ver_proc.ok:
raise RuntimeError("bash is required.")
self.about = ver_proc.output
@property
def version(self) -> str:
"""Returns the version number of the Bash-interpreter."""
matches = re.search(r"\bversion\s+(.+)\b", self.about)
# ...GNU Bash, version 4.4.19(1)-release ... --> 4.4.19(1)-release
return matches.group(1) if matches else "version_unknown"
def _exec(self, *args, **kwargs) -> BashProcess:
"""execute the bash process as a child of this process"""
return BashProcess(parent=self, args=args, **kwargs)
def command(self, script: str, **kwargs) -> BashProcess:
"""form up the command with shlex and execute"""
return self._exec(f"-c {shlex_quote(script)}", **kwargs)
def run(script=None, **kwargs):
"""Runs the given bash script."""
return Bash(**kwargs).command(script)