DOKK / manpages / debian 12 / allegro5-doc / al_ustr_offset.3alleg5.en
al_ustr_offset(3alleg5) al_ustr_offset(3alleg5)

al_ustr_offset - Allegro 5 API

#include <allegro5/allegro.h>
int al_ustr_offset(const ALLEGRO_USTR *us, int index)
    

Return the byte offset (from the start of the string) of the code point at the specified index in the string. A zero index parameter will return the first character of the string. If index is negative, it counts backward from the end of the string, so an index of -1 will return an offset to the last code point.

If the index is past the end of the string, returns the offset of the end of the string.

al_ustr_length(3alleg5)

Allegro reference manual