get_font_range_end (3) - Linux Manuals
get_font_range_end: Returns the last character of a character range in a font. Allegro game programming library.
NAMEget_font_range_end - Returns the last character of a character range in a font. Allegro game programming library.
DESCRIPTIONThis function allows you to find out the index to the last character of a character range for a font. You can pass -1 for the range parameter if you want to know the start of the whole font range, or a number from 0 to (but not including) get_font_ranges(f) to get the start of a specific character range in the font. You should check the start and end of all font ranges to see if a specific character is actually available in the font. Not all characters in the range returned by get_font_range_begin(f, -1) and get_font_range_end(f, -1) need to be available! Example:
printf("The font has a character range of %d - %d\n", get_font_range_begin(font, -1), get_font_range_end(font, -1));