51 lines
1.1 KiB
Python
Executable file
51 lines
1.1 KiB
Python
Executable file
#!/usr/bin/env python
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"""Print received signals to stdout.
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Since all signals are printed and otherwise ignored, you'll need to send
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SIGKILL (kill -9) to this process to actually end it.
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"""
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from __future__ import print_function
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import os
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import signal
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import sys
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import time
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CATCHABLE_SIGNALS = frozenset(
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set(range(1, 32)) - {signal.SIGKILL, signal.SIGSTOP, signal.SIGCHLD},
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)
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print_queue = []
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last_signal = None
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def unbuffered_print(line):
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sys.stdout.write('{}\n'.format(line))
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sys.stdout.flush()
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def print_signal(signum, _):
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print_queue.append(signum)
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if __name__ == '__main__':
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for signum in CATCHABLE_SIGNALS:
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signal.signal(signum, print_signal)
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unbuffered_print('ready (pid: {})'.format(os.getpid()))
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# loop forever just printing signals
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while True:
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if print_queue:
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signum = print_queue.pop()
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unbuffered_print(signum)
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if signum == signal.SIGINT and last_signal == signal.SIGINT:
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print('Received SIGINT twice, exiting.')
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exit(0)
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last_signal = signum
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time.sleep(0.01)
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