bash：如何知道被困时生成信号的来源？

Question

I wish to know, when a signal is caught at my signal handler, who really generated the signal. Is it user generated, or system generated, or by the OOM (Out-Of-Memory Management). The problem is, i am running database alterations using percona toolkit, and it is getting stopped everytime using SIGHUP after some 2-3 hours.

I installed a signal handler, to catch it, but wish to knwo, where it came from. An example program is below:

trapCount=0

trapFunc()
{
 trapCount=`expr $trapCount + 1`
 echo "Sighup received...$trapCount" # But how to know who generated it
}

trap 'trapFunc' HUP

while [ 1 ]
do
 echo "First Line"
 sleep 1
 echo "Second Line"
 sleep 1
 echo "Third Line"
 sleep 1
 echo "Fourth Line"
 sleep 1
 echo "Sixth Line"
 sleep 1
 echo "Seventh Line"
 sleep 1
 echo "Eighth Line"
done

Answer 1

You can't; signals are delivered by the operating system, on behalf of an anonymous signaler.