def cmd_showing_output(
command: str,
+ *,
+ timeout_seconds: Optional[float] = None,
) -> int:
"""Kick off a child process. Capture and emit all output that it
produces on stdout and stderr in a character by character manner
Args:
command: the command to execute
+ timeout_seconds: terminate the subprocess if it takes longer
+ than N seconds; None means to wait as long as it takes.
Returns:
the exit status of the subprocess once the subprocess has
- exited
+ exited. Raises TimeoutExpired after killing the subprocess
+ if the timeout expires.
Side effects:
prints all output of the child process (stdout or stderr)
"""
+ def timer_expired(p):
+ p.kill()
+ raise subprocess.TimeoutExpired(command, timeout_seconds)
+
line_enders = set([b'\n', b'\r'])
sel = selectors.DefaultSelector()
with subprocess.Popen(
stderr=subprocess.PIPE,
universal_newlines=False,
) as p:
- sel.register(p.stdout, selectors.EVENT_READ) # type: ignore
- sel.register(p.stderr, selectors.EVENT_READ) # type: ignore
- done = False
- while not done:
- for key, _ in sel.select():
- char = key.fileobj.read(1) # type: ignore
- if not char:
- sel.unregister(key.fileobj)
- if len(sel.get_map()) == 0:
- sys.stdout.flush()
- sys.stderr.flush()
- sel.close()
- done = True
- if key.fileobj is p.stdout:
- os.write(sys.stdout.fileno(), char)
- if char in line_enders:
- sys.stdout.flush()
- else:
- os.write(sys.stderr.fileno(), char)
- if char in line_enders:
- sys.stderr.flush()
- p.wait()
+ timer = None
+ if timeout_seconds:
+ import threading
+
+ timer = threading.Timer(timeout_seconds, timer_expired(p))
+ timer.start()
+ try:
+ sel.register(p.stdout, selectors.EVENT_READ) # type: ignore
+ sel.register(p.stderr, selectors.EVENT_READ) # type: ignore
+ done = False
+ while not done:
+ for key, _ in sel.select():
+ char = key.fileobj.read(1) # type: ignore
+ if not char:
+ sel.unregister(key.fileobj)
+ if len(sel.get_map()) == 0:
+ sys.stdout.flush()
+ sys.stderr.flush()
+ sel.close()
+ done = True
+ if key.fileobj is p.stdout:
+ os.write(sys.stdout.fileno(), char)
+ if char in line_enders:
+ sys.stdout.flush()
+ else:
+ os.write(sys.stderr.fileno(), char)
+ if char in line_enders:
+ sys.stderr.flush()
+ p.wait()
+ finally:
+ if timer:
+ timer.cancel()
return p.returncode
-def cmd_with_timeout(command: str, timeout_seconds: Optional[float] = None) -> int:
- """Run a command but do not let it run for more than timeout_seconds.
- This code doesn't capture or rebroadcast the command's output. It
- returns the exit value of the command or raises a TimeoutExpired
- exception if the deadline is exceeded.
+def cmd_exitcode(command: str, timeout_seconds: Optional[float] = None) -> int:
+ """Run a command silently and return its exit code once it has
+ finished. If timeout_seconds is provided and the command runs too
+ long it will raise a TimeoutExpired exception.
Args:
command: the command to run
the exit status of the subprocess once the subprocess has
exited
- >>> cmd_with_timeout('/bin/echo foo', 10.0)
+ >>> cmd_exitcode('/bin/echo foo', 10.0)
0
- >>> cmd_with_timeout('/bin/sleep 2', 0.01)
+ >>> cmd_exitcode('/bin/sleep 2', 0.01)
Traceback (most recent call last):
...
subprocess.TimeoutExpired: Command '['/bin/bash', '-c', '/bin/sleep 2']' timed out after 0.01 seconds
def cmd(command: str, timeout_seconds: Optional[float] = None) -> str:
- """Run a command and capture its output to stdout (only) into a string
- buffer. Return that string as this function's output. Raises
- subprocess.CalledProcessError or TimeoutExpired on error.
+ """Run a command and capture its output to stdout and stderr into a
+ string buffer. Return that string as this function's output.
+ Raises subprocess.CalledProcessError or TimeoutExpired on error.
Args:
command: the command to run
ret = subprocess.run(
command,
shell=True,
- # capture_output=True,
stdout=subprocess.PIPE,
stderr=subprocess.STDOUT,
check=True,
def run_silently(command: str, timeout_seconds: Optional[float] = None) -> None:
"""Run a command silently but raise subprocess.CalledProcessError if
- it fails.
+ it fails and raise a TimeoutExpired if it runs too long.
Args:
command: the command to run