os_version, os_revision - Version of the OS currently running. Allegro game programming library.

       The major and minor version of the Operating System currently running.  Set by allegro_init(). If Allegro
       for  some reason was not able to retrieve the version of the Operating System, os_version and os_revision
       will be set to -1. For example: Under Win98 SE (v4.10.2222) os_version will be set to 4  and  os_revision
       to 10.

       os_version, os_revision - Version of the OS currently running. Allegro game programming library.

os_type(3alleg4), os_multitasking(3alleg4)

Allegro                                           version 4.4.3                              os_version(3alleg4)

#include<allegro.h>externintos_version;externintos_revision;