ReadWriteFork,test

use feature 'say';
use Mojo::IOLoop::ReadWriteFork;

sub myfork {
    
    my $fork = Mojo::IOLoop::ReadWriteFork->new( ioloop => Mojo::IOLoop->singleton);
    my $cat_result = '';
 
    $fork->on(error => sub {
        my($fork, $error) = @_;
        warn $error;
             });
    $fork->on(close => sub {
        my($fork, $exit_value, $signal) = @_;
        warn "got close event";
        Mojo::IOLoop->stop;
             });
    $fork->on(read => sub {
        my($fork, $buffer) = @_; # $buffer = both STDERR and STDOUT
        say  $buffer;
        $cat_result .= $buffer;
             });
 
    $fork->run( sub { print $_[0] . "\n"; print '---' . "\n" ; print $_[1] . "\n"},
               'arg1', 'arg2'
        );
}

myfork();

Mojo::IOLoop->singleton->start;