use strict;
use warnings;

#my $ssh = 'ssh localhost';
my $ssh = 'ssh -t localhost';
open my $fh, '-|', "$ssh \"iostat 1 3\" & $ssh \"iostat 1 3\" & $ssh \"iostat 1 3\"" or die $!;
while (<$fh>) {
    print "aaaa $_";
}
close $fh;