al_get_opengl_version - Allegro 5 API

       Returns  the  OpenGL  or OpenGL ES version number of the client (the computer the program is running on),
       for the current display.  “1.0” is returned as 0x01000000, “1.2.1” is returned as 0x01020100, and “1.2.2”
       as 0x01020200, etc.

       A valid OpenGL context must exist for this function to work, which means  you  may  not  call  it  before
       al_create_display(3alleg5).

       al_get_opengl_version - Allegro 5 API

al_get_opengl_variant(3alleg5)

Allegro reference manual                                                          al_get_opengl_version(3alleg5)

              #include <allegro5/allegro_opengl.h>

              uint32_t al_get_opengl_version(void)