Implement -br flag for brief interface output.

[xraystyle]

This pull request implements the -br flag for brief output as it would work on iproute2 on Linux.

Example:

iproute2mac(master)/ $: ./src/ip.py -br a
lo0              UNKNOWN        127.0.0.1/8 ::1/128 fe80::1/64
gif0             UNKNOWN
stf0             UNKNOWN
anpi0            DOWN
anpi1            DOWN
anpi2            DOWN
en4              DOWN
en5              DOWN
en6              DOWN
en1              DOWN
en2              DOWN
en3              DOWN
bridge0          DOWN
pktap0           UNKNOWN
utun0            UNKNOWN        fe80::b9c9:9b0d:3cd3:d472/64
utun1            UNKNOWN        fe80::9f4b:b3ec:69ef:e035/64
ap1              DOWN
en0              UP             fe80::8a1:4aa3:eac7:3a43/64 10.0.0.240/24
awdl0            UP             fe80::c82f:57ff:fece:1b20/64
llw0             UNKNOWN        fe80::c82f:57ff:fece:1b20/64
utun2            UNKNOWN        fe80::917e:1dfc:aced:e98e/64
utun3            UNKNOWN        fe80::ce81:b1c:bd2c:69e/64
en7              UP             fe80::89f:2e64:1c95:ca82/64 10.0.0.238/24
utun4            UNKNOWN        10.10.24.5/32 fe80::a2ce:c8ff:feb1:24fd/64 fc00:1334:8228:a86f:5c56:4bbd:e983:8c0d/64

Additional tests have been added to check the flag is parsed correctly and working.

[xraystyle]

Hey @brona , any chance of a merge?

[brona]

Hi, hopefully I will get to this by end of July, I have some time off planned so I will go through the PRs here and merge them & release.

[brona]

Any chance you could sync the PR to current master and resolve conflicts? Thanks

[brona]

Any chance you could sync the PR to current master and resolve conflicts? Thanks

[xraystyle]

@brona I think I've pulled in your latest and fixed the conflicts while preserving all the functionality. Seems like it all works as expected.

[brona]

Thanks for updating the PR, I added few more comments. Happy to merge afterwards.

Thanks for the contribution.

[xraystyle]

Looks like everything's fixed, let me know if there's any other changes you need.

[xraystyle]

@brona Is this good, or do you need any more updates?

[brona]

Thanks for the update, I will hopefully get to merge it later this week. I left couple last nits.

[brona]

Let's use rjust or ljust ?

https://docs.python.org/3/library/stdtypes.html#str.rjust
https://docs.python.org/3/library/stdtypes.html#str.ljust

Btw isn't this actually right padded?

[brona]

Please merge it with the HEAD section below.

[tamas-lumen]

@xraystyle any chance you could take a look at the above comment? I really appreciate you implementing this, I've been missing this feature for a long time

[xraystyle]

@xraystyle any chance you could take a look at the above comment? I really appreciate you implementing this, I've been missing this feature for a long time

I'll see if I can take a look in the next few days. I should have some free time this weekend.