相关疑难解决方法(0)

这是一个简单的程序,它注册两个trap处理程序,然后显示它们trap -p.然后它做同样的事情,但在儿童背景过程中.

为什么后台进程会忽略SIGINT陷阱？

#!/bin/bash

echo "Traps on startup:"
trap -p
echo ""

trap 'echo "Received INT"' INT
trap 'echo "Received TERM"' TERM

echo "Traps set on parent:"
trap -p
echo ""

(
    echo "Child traps on startup:"
    trap -p
    echo ""

    trap 'echo "Child received INT"' INT
    trap 'echo "Child received TERM"' TERM

    echo "Traps set on child:"
    trap -p
    echo ""
) &

child_pid=$!
wait $child_pid

输出:

$ ./show-traps.sh
Traps on startup:

Traps …

这是一个示例代码,其中shell脚本在后台启动一些作业,并在收到CHLD信号(即子进程终止)后,它将采取一些操作......问题是如果父shell脚本是ZSH,它工作得很好并且捕获了CHLD信号,但其他炮弹没有!这是为什么？

#! /bin/zsh -

function foo() { echo "Trapped CHLD signal!" 
}   

trap 'foo' CHLD

./child-work1.sh &
./child-work2.sh &
./child-work3.sh &

echo 'waiting for the children'
wait
echo '--------- done ---------'