Question

I have this:

#!/bin/bash

trap 'echo $? $?' SIGINT

for i in `seq 10`; do
  echo hello from for
  sleep 10
done &

bgproc=$!
echo bgproc is $bgproc
ps -o pid,ppid,cmd
echo "waiting now"
wait $bgproc

I do

kill -2 <pid>

and get

0 0

as o/p

Question:

When I send SIGINT to this script.

Why does it terminate ? I know its because of the wait statement at the end. But whats happening there ?

Answer 1

From the Bash Reference Manual:

When Bash is waiting for an asynchronous command via the wait
builtin, the reception of a signal for which a trap has been set will
cause the wait builtin to return immediately with an exit status
greater than 128, immediately after which the trap is executed.