bash脚本杀背景（大）上按Ctrl + C儿童 [英] Bash script kill background (grand)children on Ctrl+C
问题描述
我有一个Bash脚本（猛砸3.2的Mac OS X 10.8）调用多个并行的Python脚本，以便更好地利用多个内核。每个Python脚本需要很长的时间才能完成。
I have a Bash script (Bash 3.2, Mac OS X 10.8) that invokes multiple Python scripts in parallel in order to better utilize multiple cores. Each Python script takes a really long time to complete.
问题是，如果我在Bash脚本中间按Ctrl + C，Python的脚本实际上没有被杀死。我怎么能写的Bash脚本，以便杀死它也将杀死所有的背景的孩子？
The problem is that if I hit Ctrl+C in the middle of the Bash script, the Python scripts do not actually get killed. How can I write the Bash script so that killing it will also kill all its background children?
下面是我原来的降低测试案例。不幸的是我似乎已经减少了这么多，它不再演示该问题;我的错误。
Here's my original "reduced test case". Unfortunately I seem to have reduced it so much that it no longer demonstrates the problem; my mistake.
set -e
cat >work.py <<EOF
import sys, time
for i in range(10):
time.sleep(1)
print "Tick from", sys.argv[1]
EOF
function process {
python ./work.py $1 &
}
process one
process two
wait
下面是一个完整的测试情况下，仍然高度降低了，但希望这一次会说明问题。它再现了我的机器上......不过呢，前两天我还以为的老的测试案例重现我的机器上，而今天它绝对没有。
Here's a complete test case, still highly reduced, but hopefully this one will demonstrate the problem. It reproduces on my machine... but then, two days ago I thought the old test case reproduced on my machine, and today it definitely doesn't.
#!/bin/bash -e
set -x
cat >work.sh <<EOF
for i in 0 1 2 3 4 5 6 7 8 9; do
sleep 1; echo "still going"
done
EOF
chmod +x work.sh
function kill_all_jobs { jobs -p | xargs kill; }
trap kill_all_jobs SIGINT
function process {
./work.sh $1
}
process one &
wait $!
echo "All done!"
这code继续打印仍在即使按Ctrl + C。但是，如果我移动＆安培; 从外面过程到内（即： ./工作$的.sh 1安培; ），然后按Ctrl + C按预期工作。我根本不明白这一点！
This code continues to print still going even after Ctrl+C. But if I move the & from outside process to inside (i.e.: ./work.sh $1 &), then Ctrl+C works as expected. I don't understand this at all!
在我的真实脚本中，过程包含多个命令，这些命令是长时间运行的，必须按顺序运行;所以我不知道如何移动＆安培; 在过程在这种情况下。我敢肯定，这是可能的，但一定是不平凡的。
In my real script, process contains more than one command, and the commands are long-running and must run in sequence; so I don't know how to "move the & inside process" in that case. I'm sure it's possible, but it must be non-trivial.
$ bash --version
GNU bash, version 3.2.48(1)-release (x86_64-apple-darwin12)
Copyright (C) 2007 Free Software Foundation, Inc.
编辑：非常感谢@AlanCurry教我一些东西猛砸。不幸的是我还是不明白到底发生了什么事在我的例子，但它实际上是一个有争议的问题，因为阿兰的也的有益指出，对于我的现实世界并行化的问题，Bash是错误的工具和我应该使用一个简单的makefile与使-j3 ！ 制作运行东西并联在可能的情况，也理解Ctrl + C键完美;问题解决了（即使无法解决的问题）。
Many thanks to @AlanCurry for teaching me some Bash stuff. Unfortunately I still don't understand exactly what's going on in my examples, but it's practically a moot point, as Alan also helpfully pointed out that for my real-world parallelization problem, Bash is the wrong tool and I ought to be using a simple makefile with make -j3! make runs things in parallel where possible, and also understands Ctrl+C perfectly; problem solved (even though question unanswered).
推荐答案
我知道了！所有你所要做的就是摆脱蟒蛇SIGINT处理程序。
I got it! All you have to do is get rid of that python SIGINT handler.
cat >work.py <<'EOF'
import sys, time, signal
signal.signal(signal.SIGINT, signal.SIG_DFL)
for i in range(10):
time.sleep(1)
print "Tick from", sys.argv[1]
EOF
chmod +x work.py
function process {
python ./work.py $1
}
process one &
wait $!
echo "All done!"
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