Linux to see if the port number is occupied

ETSTAT-ANP |grep Port number

Root User execution

Netstat-ntupl

n indicates that DNS is not queried

T represents the TCP protocol

U means UDP protocol

P indicates the program occupied by the query

L indicates that the query is listening on the program

View that process takes up the XXX port
Lsof-i:xxx
See where the process of process number XXX is
Ps-ef|grep xxx
PS-EF |grep Program Name
NETSTAT-NLTP |grep port number or service name

Linux to see if the port number is occupied