Python - 捕获所有信号

Question

在Linux的Python 2.6中，我可以用以下代码来处理一个TERM信号：

import signal
def handleSigTERM():
    shutdown()
signal.signal(signal.SIGTERM, handleSigTERM)    

有没有办法可以为进程接收到的所有信号设置一个处理器，而不是一个一个地设置呢？

Answer 1

如果你想不使用try这个东西，那就忽略那些无法捕捉到的信号吧。

#!/usr/bin/env python
# https://stackoverflow.com/questions/2148888/python-trap-all-signals
import os
import sys
import time
import signal

SIGNALS_TO_NAMES_DICT = dict((getattr(signal, n), n) \
    for n in dir(signal) if n.startswith('SIG') and '_' not in n )


def receive_signal(signum, stack):
    if signum in [1,2,3,15]:
        print 'Caught signal %s (%s), exiting.' % (SIGNALS_TO_NAMES_DICT[signum], str(signum))
        sys.exit()
    else:
        print 'Caught signal %s (%s), ignoring.' % (SIGNALS_TO_NAMES_DICT[signum], str(signum))

def main():
    uncatchable = ['SIG_DFL','SIGSTOP','SIGKILL']
    for i in [x for x in dir(signal) if x.startswith("SIG")]:
        if not i in uncatchable:
            signum = getattr(signal,i)
            signal.signal(signum,receive_signal)
    print('My PID: %s' % os.getpid())
    while True:
        time.sleep(1)
main()

Answer 2

从Python 3.5开始，信号常量被定义为一个枚举类型，这样使用起来就更方便了：

import signal

catchable_sigs = set(signal.Signals) - {signal.SIGKILL, signal.SIGSTOP}
for sig in catchable_sigs:
    signal.signal(sig, print)  # Substitute handler of choice for `print`

Answer 3

你可以简单地遍历信号模块中的信号，然后进行设置。

for i in [x for x in dir(signal) if x.startswith("SIG")]:
  try:
    signum = getattr(signal,i)
    signal.signal(signum,sighandler)
  except (OSError, RuntimeError) as m: #OSError for Python3, RuntimeError for 2
    print ("Skipping {}".format(i))