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.
I have spend a day enabling this extension. I have searched a lot, but failed every single time because, I have missed a single line of command. So, here are the steps I followed and get it done.
Create a directory
mkdir /tmp/phppnctl
Navigate
cd /tmp/phppnctl
Fetch the PHP source
apt-get source php5
Navigate
cd /tmp/phppnctl/php5-*/ext/pcntl
Run this command
phpize
Run this command
./configure
Make the object
make
Navigate
cd modules
Copy the file
cp pcntl.so /usr/lib/php5/<long number like 201090621>/
Enable extension to ini file
echo "extension=pcntl.so" > /etc/php5/mods-available/pcntl.ini
Execute this command
php5enmod pcntl
Restart Apache
service apache2 restart
Verify
$ php -m | grep pcntl
$ pcntl
Reference:
http://stackoverflow.com/questions/14096130/enable-pcntl-in-ubuntu-php-test-fails
http://www.lornajane.net/posts/2012/managing-php-5-4-extensions-on-ubuntu
Linux Server 