There are a number of programs out there that allow you to view a web page from right within the terminal. These text-based browsers are great for viewing pages that make basic use of html without relying on JavaScript for fancy user interactions, such as the docs page for a language.
One such program is link. If you don't already have it, you can install it
with something like homebrew. Then run links with any URL for a
magnificent, ad-free experience:
links http://www.postgresql.org/docs/current/static/functions-string.html
h/t Jack Christensen