ss is another utility to investigate sockets. It can display more TCP and state information than other tools.
Practice until you can't make it wrong.
Practice until you can't make it wrong.
history - recall lines of previous typed input
$ history
List the last 5 commands
$ history -5
Clear history
$ history -c
The last command
$ !! $ !-1
The command line N
$ !N
Put a space before command to prevent it from being saved in history