Here are some "ifconfig -a" outputs that help for the explorer/ifaces parser. The current regexp is 's/^(.*)(:[[:space:]]*flags=|Link encap).*/\1/p' You should get the interface list when you run: ifconfig -a | sed -n -r 's/^(.*)(:[[:space:]]*flags=|Link encap).*/\1/p' If you don't maybe try to replace the sed -r option by -E (works on Darwin). If you still don't get any output, the regexp might be wrong. On Archlinux: --8<----8<----8<----8<----8<----8<----8<----8<----8<----8<----8<----8<----8<-- lo: flags=73<UP,LOOPBACK,RUNNING> mtu 16436 metric 1 inet 127.0.0.1 netmask 255.0.0.0 inet6 ::1 prefixlen 128 scopeid 0x10<host> loop txqueuelen 0 (Local Loopback) RX packets 300081 bytes 49637437 (47.3 MiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 300081 bytes 49637437 (47.3 MiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 wlan0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 metric 1 inet 192.168.1.38 netmask 255.255.255.0 broadcast 192.168.1.255 inet6 fe80::ba8d:12ff:fe15:fdfa prefixlen 64 scopeid 0x20<link> ether b8:8d:12:15:fd:fa txqueuelen 1000 (Ethernet) RX packets 421381 bytes 442228597 (421.7 MiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 319266 bytes 41111233 (39.2 MiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 --8<----8<----8<----8<----8<----8<----8<----8<----8<----8<----8<----8<----8<-- On Debian Linux: --8<----8<----8<----8<----8<----8<----8<----8<----8<----8<----8<----8<----8<-- eth0 Link encap:Ethernet HWaddr 00:16:17:55:2d:00 inet addr:172.16.5.2 Bcast:172.16.255.255 Mask:255.255.0.0 inet6 addr: fe80::216:17ff:fe55:2d00/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:2854022168 errors:5 dropped:0 overruns:0 frame:4 TX packets:2200088072 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:2708386800354 (2.4 TiB) TX bytes:531552070314 (495.0 GiB) Base address:0x3000 Memory:d0120000-d0140000 eth0:1 Link encap:Ethernet HWaddr 00:16:17:55:2d:00 inet addr:172.16.5.1 Bcast:172.16.255.255 Mask:255.255.0.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 Base address:0x3000 Memory:d0120000-d0140000 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:36487087 errors:0 dropped:0 overruns:0 frame:0 TX packets:36487087 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:3388870184 (3.1 GiB) TX bytes:3388870184 (3.1 GiB) sit0 Link encap:IPv6-in-IPv4 NOARP MTU:1480 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) tap0 Link encap:Ethernet HWaddr 16:db:17:fb:a1:4a inet addr:10.254.0.1 Bcast:10.254.255.255 Mask:255.255.0.0 inet6 addr: fe80::14db:17ff:fefb:a14a/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:6 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:100 RX bytes:0 (0.0 B) TX bytes:468 (468.0 B) bond0 Link encap:Ethernet HWaddr 00:13:72:3c:bf:57 inet6 addr: fe80::213:72ff:fe3c:bf57/64 Scope:Link UP BROADCAST RUNNING MASTER MULTICAST MTU:1500 Metric:1 RX packets:6930494799 errors:0 dropped:38584515 overruns:0 frame:17 TX packets:1678579772 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:10006832472618 (9.1 TiB) TX bytes:168031719693 (156.4 GiB) bond0.123 Link encap:Ethernet HWaddr 00:13:72:3c:bf:57 inet addr:10.73.38.250 Bcast:10.73.38.255 Mask:255.255.255.0 inet6 addr: fe80::213:72ff:fe3c:bf57/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:12382478 errors:0 dropped:5777 overruns:0 frame:0 TX packets:564 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:586071334 (558.9 MiB) TX bytes:64180 (62.6 KiB) tun0 Link encap:UNSPEC HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 inet addr:172.31.255.9 P-t-P:172.31.255.10 Mask:255.255.255.255 UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1500 Metric:1 RX packets:9655 errors:0 dropped:0 overruns:0 frame:0 TX packets:15118 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:100 RX bytes:1760236 (1.6 MiB) TX bytes:14929984 (14.2 MiB) --8<----8<----8<----8<----8<----8<----8<----8<----8<----8<----8<----8<----8<-- On OpenBSD: --8<----8<----8<----8<----8<----8<----8<----8<----8<----8<----8<----8<----8<-- lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 33160 priority: 0 groups: lo inet6 ::1 prefixlen 128 inet6 fe80::1%lo0 prefixlen 64 scopeid 0x3 inet 127.0.0.1 netmask 0xff000000 em0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 lladdr 00:50:56:b3:00:15 priority: 0 groups: egress media: Ethernet autoselect (1000baseT full-duplex,master) status: active inet6 XXXX::XXX:XXXX:XXXX:XX%em0 prefixlen 64 scopeid 0x1 inet6 XXXX:XXX:XXX:XX::XXX prefixlen 64 inet XXX.XXX.XXX.XXX netmask 0xffffffc0 broadcast XXX.XXX.XXX.XXX enc0: flags=0<> priority: 0 groups: enc status: active pflog0: flags=141<UP,RUNNING,PROMISC> mtu 33160 priority: 0 groups: pflog tun1: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1500 priority: 0 groups: tun status: active inet 172.31.255.13 --> 172.31.255.14 netmask 0xffffffff tun2: flags=8011<UP,POINTOPOINT,MULTICAST> mtu 1500 priority: 0 groups: tun status: down inet 172.31.253.1 --> 172.31.253.2 netmask 0xffffffff tun0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1500 priority: 0 groups: tun status: active inet 172.31.254.1 --> 172.31.254.2 netmask 0xffffffff --8<----8<----8<----8<----8<----8<----8<----8<----8<----8<----8<----8<----8<-- On Darwin: --8<----8<----8<----8<----8<----8<----8<----8<----8<----8<----8<----8<----8<-- lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384 inet6 ::1 prefixlen 128 inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1 inet 127.0.0.1 netmask 0xff000000 gif0: flags=8010<POINTOPOINT,MULTICAST> mtu 1280 stf0: flags=0<> mtu 1280 en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500 ether 34:15:9e:2e:8b:aa inet6 fe80::3615:9eff:fe2e:8baa%en0 prefixlen 64 scopeid 0x4 inet 192.168.1.102 netmask 0xffffff00 broadcast 192.168.1.255 media: autoselect (100baseTX <full-duplex,flow-control>) status: active en1: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500 ether 7c:6d:62:a3:6f:57 inet6 fe80::7e6d:62ff:fea3:6f57%en1 prefixlen 64 scopeid 0x5 inet 192.168.2.105 netmask 0xffffff00 broadcast 192.168.2.255 media: autoselect status: active fw0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 4078 lladdr 34:15:9e:ff:fe:2e:8b:aa media: autoselect <full-duplex> status: inactive tun0: flags=8851<UP,POINTOPOINT,RUNNING,SIMPLEX,MULTICAST> mtu 1500 inet 172.31.255.29 --> 172.31.255.30 netmask 0xffffffff open (pid 24727) tun1: flags=8851<UP,POINTOPOINT,RUNNING,SIMPLEX,MULTICAST> mtu 1500 inet 172.31.254.25 --> 172.31.254.26 netmask 0xffffffff open (pid 24757) --8<----8<----8<----8<----8<----8<----8<----8<----8<----8<----8<----8<----8<--