How to view and set the Linux open firewall ports

View and open a firewall port
Firewall-cmd---list the ports
Firewall-cmd = --zone public --add-Port = 9404 / tcp --permanent
Firewall-cmd --reload
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the sudo --permanent --query-Firewall-cmd = Port 80 / TCP
the sudo systemctl the restart firewalld
the sudo All-Firewall-cmd --list