perl – 使用系统时信号传播到父级

use feature qw(say);
use strict;
use warnings;
use POSIX ();

my @data = (q(child.pl 'dummy'),q(child.pl),q(bash -c child.pl),q(sh -c child.pl));

for ( @data ) {
    say "Running command '$_'..";
    my $res = system $_;
    my $signal = $res & 127;
    my $rval = $res >> 8;
    say "Parent received return value: $rval";
    if ( $signal == POSIX::SIGINT ) {
        say "Parent received SIGINT";
    }
}

和child.pl：

use feature qw(say);
use strict;
use warnings;

eval {
    local $SIG{INT} = sub { die "Aborted by user.n" };
    sleep 10;
};
if ( $@ ) {
    print "n" . $@;
    exit 0;
}
say "Timed out..";
exit 1;

如果我在超时前按CTRL-C,输出如下：

Running command 'child.pl 'dummy''..
^C
Aborted by user.
Parent received return value: 0
Parent received SIGINT
Running command 'child.pl'..
^C
Aborted by user.
Parent received return value: 0
Running command 'bash -c child.pl'..
^C
Aborted by user.
Parent received return value: 0
Running command 'sh -c child.pl'..
^C
Aborted by user.
Parent received return value: 0
Parent received SIGINT

因此,在第一种情况和最后一种情况下,父节点接收SIGINT,而对于第二种和第三种情况,它不接收SIGINT.

这是什么原因？如何修复以使SIGINT不会传播给第一个和最后一个案例？

(我怀疑它与Shell的类型有关,即sh vs bash)