[SOLVED] BASH Script. Result of command input into variable

bcyork · 12-05-2011, 08:40 PM

Hi, I have been trying to figure this out and also new to bash scripting as well. How can I put the result of a command into a variable such as this.

CURRENT='wget -O - -q icanhazip.com'

So if I would run

echo $CURRENT

I would get an IP address?

Right now echo returns the command. I can't seem to figure out how exactly to do this. In the end I need two variables. One an IP address returned as my current external IP and the second a variable read from a file that would be an IP address as well.

Thanks!

corp769 · 12-05-2011, 08:43 PM

Here is what you need:

Code:

#!/bin/bash
var1=$(wget -O - -q icanhazip.com)
echo $var1

You need to tell it to execute the command, instead of trying to display it. You can alternatively use backticks, as such:

Code:

`wget -O - -q icanhazip.com`

Cheers,

Josh

bcyork · 12-05-2011, 08:58 PM

Thanks Josh, did the trick!

-Brian

corp769 · 12-05-2011, 10:45 PM

No problem! Please mark your thread as solved using the thread tools located at the top of the page, thanks!

Cheers,

Josh

David the H. · 12-06-2011, 12:57 PM

Note that $(..) is highly recommended over `..`.

A while back I wrote up a script/function that polls a random site for your external ip address, and keeps trying until it gets a successful hit. You can easily edit the list if you discover new ones or one goes bad. I currently have seven working addresses.

Code:

#!/bin/bash

get_current_ip() {
	local -a ipsite
	local -i xc num i

	ipsite=(
		"http://automation.whatismyip.com/n09230945.asp"
		"http://www.showmyip.com/simple/"
		"http://cfaj.freeshell.org/ipaddr.cgi"
		"https://secure.informaction.com/ipecho/"
		"http://icanhazip.com/"
		"http://wooledge.org/myip.cgi"
		"http://ifconfig.me/ip"
	       )

	xc=1
	num=${#ipsite[@]}

	until (( xc == 0 )) ; do
		(( i = RANDOM % num ))
		ip=$( wget -t 1 -T 5 -q -O- "${ipsite[i]}" )
		xc=$?
	done

	#some of the sites may output a newline or other junk, so remove any cruft.
	printf "%s" "${ip//[^0-9.]}"
}

get_current_ip

exit 0