Briefly;

// to list blocked IPs;
iptables -L INPUT -v -n

// to delete (remove block) the blocked IP;
iptables -D INPUT -s x.x.x.x -j DROP

// To add (make reliable) the IP addresses to the whitelist;
// INPUT: to inputs, OUTPUT: to outputs
iptables -A INPUT -s  x.x.x.x -j ACCEPT
iptables -A OUTPUT -s x.x.x.x -j ACCEPT

A System Monitor used in Linux-based operating systems. In Windows, the Task manager with the Taone.

Should we use it? Why?

It is up to you to use it, my advice is to use it because it has a more organized image and makes our work very easy.
According to the use of filtering by Operation numbers… He knows it.

How do I install?

Installing Htop for Rhel CentOS 5 32 bit

wget http://download.fedoraproject.org/pub/epel/5/i386/epel-release-5-4.noarch.rpm
rpm -ihv epel-release-5-4.noarch.rpm
yum install htop -y

Installing Htop for Rhel CentOS 5 64 bit

wget http://download.fedoraproject.org/pub/epel/5/x86_64/epel-release-5-4.noarch.rpm
rpm -ihv epel-release-5-4.noarch.rpm
yum install htop -y

Installing Htop for Rhel CentOS 6 32 bit

wget http://download.fedoraproject.org/pub/epel/6/i386/epel-release-6-8.noarch.rpm
rpm -ihv epel-release-6-8.noarch.rpm
yum install htop -y

Installing Htop for Rhel CentOS 6 64 bit

wget http://download.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
rpm -ihv epel-release-6-8.noarch.rpm
yum install htop -y

Installing Htop for Rhel CentOS 7 64 bit

wget http://dl.fedoraproject.org/pub/epel/7/x86_64/e/epel-release-7-8.noarch.rpm
rpm -ihv epel-release-7-8.noarch.rpm
yum install htop -y

Installing Htop for Fedora

yum install htop -y

Installing Htop for Fedora 22 +

dnf install htop -y

Installing Htop for Ubuntu

sudo apt-get install htop -y

The use of the
We start with the Htop command.

The F1 key helps you with the details of the program,
F2 Key Downloads,
The F3 key calls
F4 is the filter,
In F6, the rankings
F9 to terminate the selected process (you can change your selection with the UP ARROW keys)
The F10 or CTRL + X button allows you to exit Htop.

$gzip_pres = true; 
function gzipKontrol() 
{ 
    $kontrol = str_replace(" ","", 
        strtolower($_SERVER['HTTP_ACCEPT_ENCODING']) 
    ); 
    $kontrol = explode(",", $kontrol); 
    return in_array("gzip", $kontrol); 
} 
function bosluksil($kaynak) 
{ 
    return preg_replace("/\s+/", " ", $kaynak); 
} 
function phpPress($kaynak) 
{ 
    global $gzip_pres; 
    $sayfa_cikti = bosluksil($kaynak); 
    if (!gzipKontrol() || headers_sent() || !$gzip_pres)  
        return $sayfa_cikti; 
    header("Content-Encoding: gzip"); 
    return gzencode($sayfa_cikti); 
}

After you add this code, paste the following code at the beginning of the page that you want to compress.

ob_start("phpPress");

That’s all, plenty of traffic days.