uoffset (3) - Linux Manuals
uoffset: Finds the offset of a character in a string. Allegro game programming library.
NAME
uoffset - Finds the offset of a character in a string. Allegro game programming library.SYNOPSIS
#include <allegro.h>
int uoffset(const char *s, int index);
DESCRIPTION
Finds out the offset (in bytes from the start of the string) of the character at the specified `index' in the string `s'. 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 character. Example:
int from_third_letter = uoffset(text_string, 2);