Open Terminal and enter:

touch ~/.bash_profile
touch ~/.bashrc

To edit the file(s) use:

nano ~/.bash_profile
nano ~/.bashrc

Instead of nano you can use any decent text editor (e.g. BBEdit, TextWrangler).

Open Terminal and enter:

touch ~/.bash_profile
touch ~/.bashrc

To edit the file(s) use:

nano ~/.bash_profile
nano ~/.bashrc

Instead of nano you can use any decent text editor (e.g. BBEdit, TextWrangler).

To immediately enable any changes in the file .bash_profile use source:

source ~/.bash_profile