What is the linux command to find out the number of socket currently open?

Question

I use that :

sudo watch lsof -i -4 -a -P

and it returns a list.

how to get the count?

I tried this but doesn't work.

sudo watch lsof -i -4 -a -P | wc -l

Answer 1

I agree, this should probably be on ServerFault.

But, until then:

The issue with what you are doing is the watch command. Watch repeats a command so that you can see the output again and again over time.

My lsof doesn't accept a -4 argument, but if yours does, then

sudo lsof -i -4 -a -P | wc -l

Works for me.

Answer 2

try netstat -a | wc -l for all type of open sockets and netstat -l | wc -l for displaying server sockets.

Answer 3

To get the count, you need escape quotes to contain the entire command for the shells spawned by watch:

(Also, -4 didn't work here)

sudo watch "lsof -i -a -P | wc -l "