node -e 'console.log(1<<30);'
1073741824
echo $((1<<30))
1073741824 # same result
perl -e 'print 1<<30, "\n"'
1073741824 # same result

node -e 'console.log(1<<31);'
-2147483648 # overflow in 32bit!
echo $((1<<31))
2147483648 # correct result
perl -e 'print 1<<31, "\n"'
2147483648 # same result

# to obtain the overflow in bash
echo $((1<<63))
-9223372036854775808 # overflow in 64bit
# still perl does not
perl -e 'print 1<<63, "\n"'
9223372036854775808
perl -e 'print 1<<64, "\n"'
0 # gotcha!

# this is when I realised the problem:
node -e 'console.log(1169367104<<5);'
-1234958336
echo $((1169367104<<5))
37419747328
perl -e 'print 1169367104<<5, "\n"'
37419747328 # same result

##</code><code>##

use Test::More;
is(1169367104<<5, -1234958336, "simulated JS 32bit shift.");
done_testing;