count connections, group by IP and port

netstat has two lines of headers:

Active Internet connections (w/o servers)

Proto Recv-Q Send-Q Local Address Foreign Address State

Added a filter in the awk command to remove them

When you press TAB twice in your prompt, bash tells you something like

"Display all 4567 possibilities? (y or n)"

But when you press "y" you only get the list in the terminal output and, if you want to save it to a file, you have to copy it by hand from the vterm screen. With this utility you save the list to a file or pipe it to another command at will

You can use the file saved list to grep for a particular pattern, useful if you are searching for a command but you only remember a few letters

Prints all the lines in /etc/passwd belonging to users with a duplicated uid. It also adds the hostname to the beginning of the line.

It's been tested in AIX, Solaris and Linux.

Useful for checking the number and state of TCP connections.

We can get useful statistics from tcpdump with this simple command.

Thanks "Babak Farrokhi" to teaching me this ;)

Shows the full output of lsof.

Useful after a complete system update (without a new kernel) when you want to know, which processes need to be restarted

Uses UNIX time for sorting.

List all MAC addresses on a Linux box. sort -u is useful when having virtual interfaces.

Original: https://bugzilla.redhat.com/show_bug.cgi?id=194342

Returns a the directory depth.

If you're only using -m or -k, you will need to remember they are either in Megabyte or kilobyte forms. So by using -B, it gives you the unit of the size measurement, which helps you from reading the result faster. You can try with -B K as well.

Credit goes to brun65i but he posted it as a comment instead as an alternative. I hadn't noticed the -h option on sort before and this seems like the cleanest alternative. Thanks Brun65i!