So you wanted to install an extension on Xampp.. you execute phpize by running something like:/opt/lampp/bin/phpize.. and boooom! You start getting some xampp error messages as shown below:

grep: /opt/lampp/include/php/main/php.h: No such file or directory
grep: /opt/lampp/include/php/Zend/zend_modules.h: No such file or directory
grep: /opt/lampp/include/php/Zend/zend_extensions.h: No such file or directory
Configuring for:
PHP Api Version:
Zend Module Api No:
Zend Extension Api No:
Cannot find autoconf. Please check your autoconf installation and the
$PHP_AUTOCONF environment variable. Then, rerun this script.

Solution To This Grep Error

You are getting this phpize grep error simply because you have installed the default commonLAMP package for XAMPP, that is the normal final user version. This version is not equipped, with the source files and libraries, to build, compile and install extensions.
So, how will you do that?
ANSWER => Install the Xampp Devel package, aka the Xampp Development package.

Where To Get The Xampp Development package

You can download the Xampp Development package (Xampp Devel) on the same download page as the normal one, here! Just look for ‘Development package‘ and click to download! Bingo you have it!

How To Install Xampp Devel / Xampp Development Package?

Simple!
I assume you have by now already downloaded your package, mine at the time of this writing, is named as xampp-linux-devel-1.7.4.tar.gz.

To install, simply execute the following shell command: sudo tar xvfz xampp-linux-devel-1.7.4.tar.gz -C /opt

– NOTE: This extraction will extract and place those needed development libraries and source file inside your existing Lampp folder in /opt/lampp/

Voila!
(happy Mint-Xampp-ing)