Perl无法正常打印

if ($MySQL)
{
    print \"Has MySQL, Installing: \";
    $mysqlCmd = \"/path/to/script/mysql-install.pl $person > /dev/null 2>&1\";
    $ssh_d->cmd(\"$mysqlCmd\");
    print \"OK\\n\";
}

$|

$|

$| = 1;
print \"Enter a number between 3 and 5: \";
chomp( my $answer = <STDIN> );

select

$| = 1;
print \"This is now unbuffered printing. \"
sleep 3;
print \"You no longer have to wait for the NL character. \";
sleep 3;
print \"\\n\";