Question

I’m trying to get the list of networks interfaces from the command-line in this form:

"wlan0","eth0","lo"

I don’t need to get them in a special order.

I can do this:

wlan0,eth0,lo

with this super non-optimized command, after having searched a lot and after I think I’ve reached my limits:

ifconfig -a | grep -E '' | sed -n 's/^\([^ ]\+\).*/\1/p' | tr -d '\n' | sed s/:/,/g | sed 's/.$//' 

Answer 1

I’ll add this one to the pile. Add the quotes in the first sed, then just join the lines with paste.

ifconfig -a | sed -n 's/^\([^ ]\+\).*/"\1"/p' | paste -sd ","

This is better than tr since there’s no trailing comma.

Better yet, since ifconfig -a output can’t really be counted on to stay consistent, check /sys/class/net

ls /sys/class/net | sed -e 's/^\(.*\)$/"\1"/' | paste -sd ","