Process Control support in PHP implements the Unix style of process creation, program execution, signal handling and process termination. Process Control should not be enabled within a web server environment and unexpected results may happen if any Process Control functions are used within a web server environment.
This article explains the steps to enable pcntl extension in Cpanel server.
Create a file appropriate to the php version in the server.
For all PHP 4 versions — /var/cpanel/easy/apache/rawopts/all_php4
For all PHP 5 versions — /var/cpanel/easy/apache/rawopts/all_php5
Add this to the file: --enable-pcntl
Run easyapache and recompile apache,php