[ale] Get host's IP address as an unprivileged user?

[Geoffrey Myers]

Derek Atkins wrote:
> JD <jdp at algoloma.com> writes:
> 
>> On 06/03/2011 09:25 AM, James Sumners wrote:
>>> I need to get the IP address of the local machine on which a script is
>>> being executed. The script is going to be run by an unprivileged user
>>> (so /sbin is not in the PATH). Does anyone know of a better way than
>>> this:
>>>
>>> IP=$(host $(hostname) | awk '{print $4}')
>>>
>> I never trust the PATH in scripts.  Anyone can call /sbin/ifconfig.
>> If you must, just add :/sbin to your PATH (ew).
> 
> Like JD said, you do not need to be root to run ifconfig:.
> 
> [warlord at dev webdav]$ whoami
> warlord
> [warlord at dev webdav]$ /sbin/ifconfig wlan0 
> wlan0     Link encap:Ethernet  HWaddr 00:21:6A:90:98:58  
>           inet addr:192.168.248.100  Bcast:192.168.248.255  Mask:255.255.255.0
> ...
> [warlord at dev webdav]$ /sbin/ifconfig wlan0 | grep 'inet addr' | tr : ' ' | awk '{print $3}'
> 192.168.248.100

You probably can't guarantee that the device will be wlan0.  Further, 
you can combine your grep, awk, and tr into a single awk script:

ifconfig| awk -F'[" ":]' '/Bcast/ {print  $16, NF}'

Note, I've looking for Bcast, should match any configured interfaces. 
Problem is, if you have more then one interface configured....


> 
> -derek


-- 
Until later, Geoffrey

"I predict future happiness for America if they can prevent
the government from wasting the labors of the people under
the pretense of taking care of them."
- Thomas Jefferson