SHOW FULL PROCESSLIST for some host does not show `Client port` I am executing Show Full Processlist; and output does not show client port for some hosts in Host column

Documentation says that each and every connection has host:client_port format.

My question is for some of the host column it just shows localhost without client port

What could be the reason behind this?
The reason is that it's not connected via TCP/IP, so there isn't a port.

MySQL allows local clients to connect via a "socket file", which is located on the file system (/var/lib/mysql/mysql.sock, for example`).