php-apigen software package provides API documentation generator for PHP 5.3+, you can install in your Ubuntu 14.04 LTS (Trusty Tahr) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install php-apigen
php-apigen is installed in your system.
Make ensure the php-apigen package were installed using the commands given below,
$ sudo dpkg-query -l | grep php-apigen *
You will get with php-apigen package name, version, architecture and description in a table
| Distro | Ubuntu 14 04 lts trusty tahr |
| Section | PHP |
| Package | php-apigen |
| Version | 2.8.0+dfsg-3 |
| Description | API documentation generator for PHP 5.3+ |
| Sub Section | PHP |