Gather information via Terminal

I keep aliases in ~/.bash_profile.

Terminal and iTerm 2 open new shells as login shells by default. When bash is invoked as an interactive login shell, it reads ~/.bash_profile but not ~/.bashrc. The terminal emulators on other platforms often open new shells as non-login shells, so for example bash reads ~/.bashrc but not ~/.bash_profile. OS X users often use ~/.bash_profile as the personal configuration file corresponding to ~/.bashrc on other platforms, but it is also possible to source ~/.bashrc from ~/.bash_profile or to tell Terminal or iTerm 2 to open new shells as non-login shells.

If both ~/.profile and ~/.bash_profile exist, bash only reads ~/.bash_profile when it is invoked as an interactive login shell. ~/.profile is also used by other shells and programs that might not understand the same configuration options as bash.

/etc/bashrc is owned by root, and it might get replaced when you upgrade OS X.

See man bash|less +^INVOCATION or https://www.gnu.org/software/bash/manual/html_node/Bash-Startup-Files.html for more information.

I've whipped up this nice code snippet, try it out, it should work well for your specific application.

set device to "Ethernet"

set getInfo to paragraphs of (do shell script "networksetup -getinfo " & device)
set ipAddress to ((item 2 of getInfo) as string)
set subnetMask to ((item 3 of getInfo) as string)
set router to ((item 4 of getInfo) as string)
-- You could use the output here, and remove the rest of the script, or continue to remove the excess wordage.

set ipAddress to ((characters 13 through -1 of ipAddress) as string)
set subnetMask to ((characters 14 through -1 of subnetMask) as string)
set router to ((characters 9 through -1 of router) as string)