How to substract two stdout lists in linux bash - arrays

Question

heed help.
I have one list "A" from
netstat -ntlp | grep -oP ":[:1]?[:1]?(.*)+" | grep -oP "\d\d+"
it looks like
80
443
8080
22
25
I have another list "B" from
ufw status numbered | grep -oP "\] \d+" | grep -oP "\d+"
it looks as
80
443
22
So i want to know, which ports are listening, but not open with ufw, i.e. substract ["A"]-["B"]
and going to see
8080
25
with some command like
netstat -ntlp | grep -oP ":[:1]?[:1]?(.*)+" | grep -oP "\d\d+" | SELECT ALL NOT IN `ufw status numbered | grep -oP "\] \d+" | grep -oP "\d+"`
How to do this?

Answer 1

Typically it's comm job:
netstat -ntlp | grep -oP ":[:1]?[:1]?(.*)+" | grep -oP "\d\d+" |
sort | comm -23 - <(ufw status numbered | grep -oP "\] \d+" | grep -oP "\d+" | sort)

Answer 2

You may use grep:
grep -vxFf <(cmd2) <(cmd1)
Here replace cmd1 with netstat ... command and replace cmd2 with ufw ... command.

Answer 3

This solution requires pre-sorting of the outputs:
$ netstat -ntlp | grep -oP ":[:1]?[:1]?(.*)+" | grep -oP "\d\d+" | sort > A
^^^^^^
$ ufw status numbered | grep -oP "\] \d+" | grep -oP "\d+" | sort > B
^^^^^^
Items unique to A:
$ comm -23 A B
25
8080
$
... but also, in case you require, items unique to B:
$ comm -13 A B
$
... and items common to A and B:
$ comm -12 A B
22
443
80
$
See man comm for details.

Answer 4

You can check the uniq -u command:
http://man7.org/linux/man-pages/man1/uniq.1.html
You pass a group of lines to uniq -d and redirect to an output. It will print only the duplicated ones.
So you just need to aggregate both results from list A and list B into a text:
List A:
netstat -ntlp | grep -oP ":[:1]?[:1]?(.*)+" | grep -oP "\d\d+" >> output.txt
List B:
ufw status numbered | grep -oP "\] \d+" | grep -oP "\d+" > output.txt >> output.txt`
(NOTE: You use '>>' over '>' to append the content to end of the file. So make sure to clean it on each iteration!)
Then:
uniq -u output.txt
You can redirect the uniq -u output too, if needed:
uniq -u output.txt > gotuniques.txt
Edit: formatting
Edit2: I was confused by -d when the answer requires -u.