Get a summary of network devices in the system

for i in /sys/class/net/*; do e=`basename $i`; echo "# $e"; sudo ethtool $e | grep -E "Link|Speed" ; done
Basically an improvement on an earlier ethtool command line.
Sample Output
# eth0
	Speed: Unknown! (65535)
	Link detected: no
# eth1
	Speed: 100Mb/s
	Link detected: yes
# lo
	Link detected: yes
# pan0
	Link detected: yes
# tap1
	Speed: 10Mb/s
	Link detected: no

By: hank
2009-04-25 14:32:08

What Others Think

Again, your way of using "ls" inside a for loop is inappropriate. Just don't. for i in /sys/class/net/*; do ...
ubersoldat · 612 weeks and 3 days ago
give the guy some credit. this is still awesome.
linuxrawkstar · 612 weeks and 3 days ago
So let's make things straight. This is the corrected line: for i in `ls --color=none /sys/class/net/*`; do echo "# $i"; sudo ethtool $i | grep -E "Link|Speed" ; done
dotanmazor · 612 weeks and 1 day ago
What? This can't work like that. It will pass the whole path to ethtool and fail. You should have the command cd into /sys/class/net before doing an ls, a such: for i in `cd /sys/class/net ; ls -d *`; do ...
tduvally · 490 weeks and 6 days ago
Just fixed it - thanks for the suggestions.
hank · 490 weeks and 6 days ago

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

You must be signed in to comment.

What's this? is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands

Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.


Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for: