Mac Why install PHP extension error, how to resolve

When the Mac system is upgraded to 10.9 (Mavericks), the PHP extension is installed and the phpize prompts for the following error:

Cannot find autoconf. Please check your autoconf installation

and the $PHP _autoconf environment variable.

Solutions

Install Homebrew First:

Ruby-e "$ (curl-fssl https://raw.github.com/Homebrew/homebrew/go/install)"

Moved to:

Ruby-e "$ (curl-fssl https://raw.githubusercontent.com/Homebrew/install/master/install)"

Then install autoconf:

Brew Install autoconf