trap通过信号监控进程

脚本master.sh
#! /bin/bash
jk1()
{
   echo "child is working !!!!"
   a=1
   b=0
}


jk2()
{
   echo "child is over!!!!!!"
   b=1
   a=0
}




jk3()
{
   echo "child is dead !!!!"


}


trap "" 15 16
trap jk1 15
trap jk2 16


echo $a
#echo "going here 1"
a=0
b=0


main()
{
while :
do




if [ $a -eq 1 ]
then
        child_pid=`pgrep child.sh`


        if [ -z "${child_pid}" ] && [ $b -ne 1 ]
        then
                jk3
                a=2
                break
        fi
fi


if [ $a -ne 1 ]
then
        child_pid=`pgrep child.sh`
        if [ "${child_pid}" ]
        then
                jk1
        fi
fi


done
}

while :
do
main
sleep 2
#echo "going here 2"
done
v

脚本child.sh


#! /bin/bash
master_pid=`pgrep master.sh` && kill -15 $master_pid
echo $$


a=1


while [ $a -ne 20 ]
do
sleep 1
((a=a+1))
echo $a


done

master_pid=`pgrep master.sh` && kill -16 $master_pid || echo "master is dead , I'm goging over"