Curl is not installed by default on many common distros anymore. wget always is :) wget -qO- ifconfig.me/ip

-P tells grep to use perl regex matches (only works on the GNU grep as far as I know.)

Or even easier, if it's available: killall firefox I have no idea why you would want to rely on two unusual dependencies to do something that can be done a hundred ways from coreutils...

Removes all empty lines: ^$ and all lines starting with hash: ^# Show Sample Output

Usefull for when you don't have nmap and need to find a missing host. Pings all addresses from 10.1.1.1 to 10.1.1.254, modify for your subnet. Timeout set to 1 sec for speed, if running over a slow connection you should raise that to avoid missing replies. This will clean up the junk, leaving just the IP address: for i in {1..254}; do ping -c 1 -W 1 10.1.1.$i | grep 'from' | cut -d' ' -f 4 | tr -d ':'; done Show Sample Output

Prints a log of phonecalls placed from/to an asterisk server, formated into an easily readable table. You can use partial number/queue matches, or use .* to match everything. Show Sample Output

Gets the IP addresses of all interfaces except loopback. Cuts out all of the extra text. Shorter than the other options, and much easier to type. 'ifconfig | grep cast' is enough to get the IP address, but it doesn't strip the rest of the junk out. Show Sample Output