al_get_allegro_version - Man Page

#include <allegro5/allegro.h>

uint32_t al_get_allegro_version(void)

Returns the (compiled) version of the Allegro library, packed into a single integer as groups of 8 bits in the form (major << 24) | (minor << 16) | (revision << 8) | release.

You can use code like this to extract them:

uint32_t version = al_get_allegro_version();
int major = version >> 24;
int minor = (version >> 16) & 255;
int revision = (version >> 8) & 255;
int release = version & 255;

The release number is 0 for an unofficial version and 1 or greater for an official release. For example “5.0.2[1]” would be the (first) official 5.0.2 release while “5.0.2[0]” would be a compile of a version from the “5.0.2” branch before the official release.

al_get_allegro_acodec_version(3), al_get_allegro_audio_version(3), al_get_allegro_color_version(3), al_get_allegro_font_version(3), al_get_allegro_image_version(3), al_get_allegro_memfile_version(3), al_get_allegro_native_dialog_version(3), al_get_allegro_physfs_version(3), al_get_allegro_primitives_version(3), al_get_allegro_ttf_version(3), al_get_allegro_video_version(3).