我有一个名为monitiq_install.py的python脚本，它使用subprocess python模块调用其他脚本（或模块）。但是，如果用户发送键盘中断（CTRL + C），它将退出，但有例外。我希望它退出，但很好。
我的代码：
import os
import sys
from os import listdir
from os.path import isfile, join
from subprocess import Popen, PIPE
import json
# Run a module and capture output and exit code
def runModule(module):
try:
# Run Module
process = Popen(os.path.dirname(os.path.realpath(__file__)) + "/modules/" + module, shell=True, stdout=PIPE, bufsize=1)
for line in iter(process.stdout.readline, b''):
print line,
process.communicate()
exit_code = process.wait();
return exit_code;
except KeyboardInterrupt:
print "Got keyboard interupt!";
sys.exit(0);
我得到的错误如下：
python monitiq_install.py -a
Invalid module filename: create_db_user_v0_0_0.pyc
Not Running Module: '3parssh_install' as it is already installed
######################################
Running Module: 'create_db_user' Version: '0.0.3'
Choose username for Monitiq DB User [MONITIQ]
^CTraceback (most recent call last):
File "/opt/monitiq-universal/install/modules/create_db_user-v0_0_3.py", line 132, in <module>
inputVal = raw_input("");
Traceback (most recent call last):
File "monitiq_install.py", line 40, in <module>
KeyboardInterrupt
module_install.runModules();
File "/opt/monitiq-universal/install/module_install.py", line 86, in runModules
exit_code = runModule(module);
File "/opt/monitiq-universal/install/module_install.py", line 19, in runModule
for line in iter(process.stdout.readline, b''):
KeyboardInterrupt
解决方案或一些指示会有所帮助：）
- 编辑 用try catch
Running Module: 'create_db_user' Version: '0.0.0'
Choose username for Monitiq DB User [MONITIQ]
^CGot keyboard interupt!
Traceback (most recent call last):
File "monitiq_install.py", line 36, in <module>
module_install.runModules();
File "/opt/monitiq-universal/install/module_install.py", line 90, in runModules
exit_code = runModule(module);
File "/opt/monitiq-universal/install/module_install.py", line 29, in runModule
sys.exit(0);
NameError: global name 'sys' is not defined
Traceback (most recent call last):
File "/opt/monitiq-universal/install/modules/create_db_user-v0_0_0.py", line 132, in <module>
inputVal = raw_input("");
KeyboardInterrupt
答案 0 :(得分：9)
如果在终端中按 Ctrl + C ，则会将SIGINT发送到进程组内的所有进程。请参阅child process receives parent's SIGINT。
这就是为什么你看到来自子进程的回溯，尽管在父进程中尝试/除了KeyboardInterrupt。
您可以禁止子进程的stderr输出：stderr=DEVNULL。或者在新的流程组中启动它：start_new_session=True：
import sys
from subprocess import call
try:
call([sys.executable, 'child.py'], start_new_session=True)
except KeyboardInterrupt:
print('Ctrl C')
else:
print('no exception')
如果您在上面的示例中删除了start_new_session=True，则可能会在孩子中引发KeyboardInterrupt，您可能会获得回溯。
如果subprocess.DEVNULL不可用;你可以使用DEVNULL = open(os.devnull, 'r+b', 0)。如果start_new_session参数不可用;你可以在POSIX上使用preexec_fn=os.setsid。
答案 1 :(得分：2)
您可以使用try执行此操作，但以下情况除外：
import subprocess
try:
proc = subprocess.Popen("dir /S", shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
while proc.poll() is None:
print proc.stdout.readline()
except KeyboardInterrupt:
print "Got Keyboard interrupt"
您可以避免执行shell=True作为最佳安全措施。
答案 2 :(得分：1)
这段代码会产生一个子进程，并像 shell (bash, zsh, ...) 一样向他们传递信号，比如 SIGINT，...。
这意味着 KeyboardInterrupt 不再被 Python 进程看到，但是子进程收到它并被正确杀死。
它的工作原理是在 Python 设置的新前台进程组中运行进程。
import os
import signal
import subprocess
import sys
import termios
def run_as_fg_process(*args, **kwargs):
"""
the "correct" way of spawning a new subprocess:
signals like C-c must only go
to the child process, and not to this python.
the args are the same as subprocess.Popen
returns Popen().wait() value
Some side-info about "how ctrl-c works":
https://unix.stackexchange.com/a/149756/1321
fun fact: this function took a whole night
to be figured out.
"""
old_pgrp = os.tcgetpgrp(sys.stdin.fileno())
old_attr = termios.tcgetattr(sys.stdin.fileno())
user_preexec_fn = kwargs.pop("preexec_fn", None)
def new_pgid():
if user_preexec_fn:
user_preexec_fn()
# set a new process group id
os.setpgid(os.getpid(), os.getpid())
# generally, the child process should stop itself
# before exec so the parent can set its new pgid.
# (setting pgid has to be done before the child execs).
# however, Python 'guarantee' that `preexec_fn`
# is run before `Popen` returns.
# this is because `Popen` waits for the closure of
# the error relay pipe '`errpipe_write`',
# which happens at child's exec.
# this is also the reason the child can't stop itself
# in Python's `Popen`, since the `Popen` call would never
# terminate then.
# `os.kill(os.getpid(), signal.SIGSTOP)`
try:
# fork the child
child = subprocess.Popen(*args, preexec_fn=new_pgid,
**kwargs)
# we can't set the process group id from the parent since the child
# will already have exec'd. and we can't SIGSTOP it before exec,
# see above.
# `os.setpgid(child.pid, child.pid)`
# set the child's process group as new foreground
os.tcsetpgrp(sys.stdin.fileno(), child.pid)
# revive the child,
# because it may have been stopped due to SIGTTOU or
# SIGTTIN when it tried using stdout/stdin
# after setpgid was called, and before we made it
# forward process by tcsetpgrp.
os.kill(child.pid, signal.SIGCONT)
# wait for the child to terminate
ret = child.wait()
finally:
# we have to mask SIGTTOU because tcsetpgrp
# raises SIGTTOU to all current background
# process group members (i.e. us) when switching tty's pgrp
# it we didn't do that, we'd get SIGSTOP'd
hdlr = signal.signal(signal.SIGTTOU, signal.SIG_IGN)
# make us tty's foreground again
os.tcsetpgrp(sys.stdin.fileno(), old_pgrp)
# now restore the handler
signal.signal(signal.SIGTTOU, hdlr)
# restore terminal attributes
termios.tcsetattr(sys.stdin.fileno(), termios.TCSADRAIN, old_attr)
return ret
# example:
run_as_fg_process(['openage', 'edit', '-f', 'random_map.rms'])