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May 19, 2015 - A Look At The New Commandlinefu
I've put together a short writeup on what kind of newness you can expect from the next iteration of clfu. Check it out here.
March 2, 2015 - New Management
I'm Jon, I'll be maintaining and improving clfu. Thanks to David for building such a great resource!

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Fetch the Gateway Ip Address

Terminal - Fetch the Gateway Ip Address
netstat -nr | awk 'BEGIN {while ($3!="") getline; print $2}'
2010-03-07 01:47:55
User: freethinker
Functions: awk netstat
Fetch the Gateway Ip Address

This is to fetch the Gateway Ip Address of a machine. Use the below format to put the value in a variable if you wish to find the gateway ip in a script

GATEWAY=$(netstat -nr | awk 'BEGIN {while ($3!="") getline; print $2}')


There are 3 alternatives - vote for the best!

Terminal - Alternatives
ip route list match | cut -d " " -f 3
2010-03-07 15:41:18
User: BaS
Functions: cut route

Better use iproute2 !

/sbin/route -n | grep "^0\.0\.0\.0" | awk '{ print $2 }'
2010-03-07 13:59:57
User: BorneBjoern
Functions: awk grep

same thing without loop ;)

Know a better way?

If you can do better, submit your command here.

What others think

Well unfortunately this did not work on my BSD box... but you could us this instead.

For FreeBSD either of these will work.

awk -F '"' '/defaultrouter/{print $2}' /etc/rc.conf

netstat -nr | awk '/default/{ print $2}'

Now on Mac OS X it get's a little trickier because IPv6 is enabled by default. The following works for me.

netstat -nr | awk '/default/{ print $2;exit}'

Oh on FreeBSD there's a third option if your are running bash but it can get messy. This reads the file into the shell as an include script Remember bash is not installed by default on and BSD.

. /etc/rc.conf

echo $defaultrouter


Mikel King

Comment by mikelking 424 weeks and 4 days ago

Pretty cool, I should have actually used the subject line "Fetch the Gateway Ip Address on Linux" ...

Comment by freethinker 424 weeks and 4 days ago

Your point of view

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