in reply to Re^4: Parallel::ForkManager run_on_finish Canot get Exit Code of Child process
in thread Parallel::ForkManager run_on_finish Canot get Exit Code of Child process

First,

my $curlResult = `echo $?`; chomp($curlResult);
is the same thing as
my $curlResult = $?;

Second, $? doesn't contain the exit code. Well, not just the exit code. See its documentation.