下面是运行任意命令返回其标准输出数据的Python代码，或在非零退出码上引发异常:
proc = subprocess.Popen(
cmd,
stderr=subprocess.STDOUT, # Merge stdout and stderr
stdout=subprocess.PIPE,
shell=True)
communication用于等待进程退出:
stdoutdata, stderrdata = proc.communicate()
子进程模块不支持超时——杀死运行超过X秒的进程的能力——因此，通信可能需要很长时间才能运行。
在Windows和Linux上运行的Python程序中实现超时的最简单方法是什么?
当前回答
虽然我还没有广泛地研究它，但我在ActiveState中发现的这个装饰器似乎对这类事情非常有用。伴随着subprocess.Popen(…， close_fds=True)，至少我已经准备好在Python中编写shell脚本。
其他回答
我已经修改了sussudio的答案。现在函数返回:(returncode, stdout, stderr, timeout) - stdout和stderr被解码为utf-8字符串
def kill_proc(proc, timeout):
timeout["value"] = True
proc.kill()
def run(cmd, timeout_sec):
proc = subprocess.Popen(shlex.split(cmd), stdout=subprocess.PIPE, stderr=subprocess.PIPE)
timeout = {"value": False}
timer = Timer(timeout_sec, kill_proc, [proc, timeout])
timer.start()
stdout, stderr = proc.communicate()
timer.cancel()
return proc.returncode, stdout.decode("utf-8"), stderr.decode("utf-8"), timeout["value"]
另一种选择是写入临时文件以防止标准输出阻塞，而不需要使用communication()轮询。在其他答案没有的地方，这个方法对我有用;比如在窗户上。
outFile = tempfile.SpooledTemporaryFile()
errFile = tempfile.SpooledTemporaryFile()
proc = subprocess.Popen(args, stderr=errFile, stdout=outFile, universal_newlines=False)
wait_remaining_sec = timeout
while proc.poll() is None and wait_remaining_sec > 0:
time.sleep(1)
wait_remaining_sec -= 1
if wait_remaining_sec <= 0:
killProc(proc.pid)
raise ProcessIncompleteError(proc, timeout)
# read temp streams from start
outFile.seek(0);
errFile.seek(0);
out = outFile.read()
err = errFile.read()
outFile.close()
errFile.close()
预先设置Linux命令超时并不是一个糟糕的解决方法，它对我来说是有效的。
cmd = "timeout 20 "+ cmd
subprocess.Popen(cmd.split(), stdout=subprocess.PIPE, stderr=subprocess.PIPE)
(output, err) = p.communicate()
这是我的解决方案，我使用线程和事件:
import subprocess
from threading import Thread, Event
def kill_on_timeout(done, timeout, proc):
if not done.wait(timeout):
proc.kill()
def exec_command(command, timeout):
done = Event()
proc = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
watcher = Thread(target=kill_on_timeout, args=(done, timeout, proc))
watcher.daemon = True
watcher.start()
data, stderr = proc.communicate()
done.set()
return data, stderr, proc.returncode
在行动:
In [2]: exec_command(['sleep', '10'], 5)
Out[2]: ('', '', -9)
In [3]: exec_command(['sleep', '10'], 11)
Out[3]: ('', '', 0)
下面是Alex Martelli的解决方案，它是一个具有适当进程终止的模块。其他方法不起作用，因为它们没有使用proc. communication()。所以如果你有一个产生大量输出的进程，它会填满它的输出缓冲区，然后阻塞，直到你从中读取一些东西。
from os import kill
from signal import alarm, signal, SIGALRM, SIGKILL
from subprocess import PIPE, Popen
def run(args, cwd = None, shell = False, kill_tree = True, timeout = -1, env = None):
'''
Run a command with a timeout after which it will be forcibly
killed.
'''
class Alarm(Exception):
pass
def alarm_handler(signum, frame):
raise Alarm
p = Popen(args, shell = shell, cwd = cwd, stdout = PIPE, stderr = PIPE, env = env)
if timeout != -1:
signal(SIGALRM, alarm_handler)
alarm(timeout)
try:
stdout, stderr = p.communicate()
if timeout != -1:
alarm(0)
except Alarm:
pids = [p.pid]
if kill_tree:
pids.extend(get_process_children(p.pid))
for pid in pids:
# process might have died before getting to this line
# so wrap to avoid OSError: no such process
try:
kill(pid, SIGKILL)
except OSError:
pass
return -9, '', ''
return p.returncode, stdout, stderr
def get_process_children(pid):
p = Popen('ps --no-headers -o pid --ppid %d' % pid, shell = True,
stdout = PIPE, stderr = PIPE)
stdout, stderr = p.communicate()
return [int(p) for p in stdout.split()]
if __name__ == '__main__':
print run('find /', shell = True, timeout = 3)
print run('find', shell = True)
