ubuntu - configure: error: zlib.h was not found or is not usable. Please install zlib

Install these packages, libgcrypt11-dev and zlib1g-dev

# apt-get install libgcrypt11-dev

# apt-get install zlib1g-dev

Starting httpd: [date] [warn] _default_ VirtualHost overlap on port 80, the first has precedence

To remove this error, uncomment following line in /etc/httpd/conf/httpd.conf

NameVirtualHost *:80

Now restart httpd

# service httpd restart

Apache - Browser throwing sql query and php code

Apache - Browser showing mysql queries and php code

Open php.ini file
Find "short_open_tag = Off" and make it enabled
short_open_tag = On
Restart Apache. If you are using xampp, restart lampp after making changes in php.ini

If you are using xampp and you are still facing this problem.
Uncomment following line in the file /opt/lampp/etc/httpd.conf

Include etc/extra/httpd-xampp.conf

This line should not be commented.

If you are using centos / RHEL / fedora and you are still facing the problem
Run following command in the terminal.

# yum install php php-mysql -y