al_set_config_value - Allegro 5 API

       Set a value in a section of a configuration.  If the section doesn’t yet exist, it will be created.  If a
       value  already  existed for the given key, it will be overwritten.  The section can be NULL or “” for the
       global section.

       For consistency with the on-disk format of config files, any leading  and  trailing  whitespace  will  be
       stripped  from  the  value.  If you have significant whitespace you wish to preserve, you should add your
       own quote characters and remove them when reading the values back in.

       al_set_config_value - Allegro 5 API

al_get_config_value(3alleg5)

Allegro reference manual                                                            al_set_config_value(3alleg5)

              #include <allegro5/allegro.h>

              void al_set_config_value(ALLEGRO_CONFIG *config,
                 const char *section, const char *key, const char *value)