macos – How to find the currently connected network service from the command line?

Not certain if this is helpful to any individual, but as I was tinkering with the identical dilemma, I came to this answer:

ifconfig | grep flags=8863 | grep -v bridge

The output will glimpse something like this, and lists only the ethernet ports and wifi that are in lively use:

en0: flags=8863 mtu 1500
en1: flags=8863 mtu 1500

If you would like to see the assigned IPv4 handle as nicely:

ifconfig | grep 'flags=8863|inet ' | grep -v 'bridge|127...1'

Which produces something like this

en0: flags=8863 mtu 1500
    inet 192.168.2.147 netmask 0xffffff00 broadcast 192.168.2.255
en1: flags=8863 mtu 1500
    inet 192.168.2.244 netmask 0xffffff00 broadcast 192.168.2.255

Another alternative:

scutil --nwi

Which demonstrates the on line community units the previous line actually demonstrates the at the moment active network interfaces:

Community information

IPv4 network interface information and facts
     en0 : flags      : 0x5 (IPv4,DNS)
           deal with    : 192.168.2.147
           get to      : 0x00000002 (Reachable)
     en1 : flags      : 0x5 (IPv4,DNS)
           tackle    : 192.168.2.244
           access      : 0x00000002 (Reachable)

   Arrive at : flags 0x00000002 (Reachable)

IPv6 network interface info
   No IPv6 states discovered


   Get to : flags 0x00000000 (Not Reachable)

Network interfaces: en0 en1

Even more processing, if required, is up to you. 🙂

Be aware:

Brain you that I am not an skilled on the flags (8863).
You can discover the flag particulars in the if.h header file – Spotlight is your friend in discovering “if.h”. I found mine for instance here:

/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk/Technique/Library/Frameworks/Kernel.framework/Versions/A/Headers/internet/if.h

which will present you what the flags indicate (maintain in brain: hexadecimal)

#define IFF_UP          0x1             /* interface is up */
#outline IFF_BROADCAST   0x2             /* broadcast address legitimate */
#define IFF_DEBUG       0x4             /* flip on debugging */
#define IFF_LOOPBACK    0x8             /* is a loopback net */
#define IFF_POINTOPOINT 0x10            /* interface is issue-to-stage link */
#outline IFF_NOTRAILERS  0x20            /* out of date: steer clear of use of trailers */
#define IFF_Working     0x40            /* assets allocated */
#define IFF_NOARP       0x80            /* no address resolution protocol */
#outline IFF_PROMISC     0x100           /* obtain all packets */
#outline IFF_ALLMULTI    0x200           /* obtain all multicast packets */
#outline IFF_OACTIVE     0x400           /* transmission in progress */
#determine IFF_SIMPLEX     0x800           /* can't listen to individual transmissions */
#define IFF_LINK0       0x1000          /* per connection layer outlined little bit */
#outline IFF_Website link1       0x2000          /* for every connection layer described bit */
#outline IFF_Backlink2       0x4000          /* for every hyperlink layer outlined bit */
#determine IFF_ALTPHYS     IFF_Link2       /* use alternate actual physical relationship */
#determine IFF_MULTICAST   0x8000          /* supports multicast */