/etc/profile

to edit this file

nano /etc/profile

I wanted to add a shortcut for Zend Framework tools. I append this to the end of file

alias zf=/Applications/MAMP/bin/php/php5.4.4/bin/zf.sh


Then CTRL + o to Save
CTROL + x to exit

Edit:

Turns out that the file located at /etc/profile is the global config for BASH, you can use .profile under the user directory.