Allegro 5 api
#include <allegro5/allegro.h> int al_ustr_find_set(const ALLEGRO_USTR *us, int start_pos, const ALLEGRO_USTR *accept)
This function finds the first code point in us, beginning from byte offset start_pos, that matches any code point in accept. Returns the position if a code point was found. Otherwise returns -1.
al_ustr_find_set_cstr(3alleg5), al_ustr_find_cset(3alleg5)