size_t strxfrm(char *str1
, const char *str2
Transforms the string str2 and places the result into str1. It copies at most n characters into str1 including the null terminating character. The transformation occurs such that
strcmp applied to two separate converted strings returns the same value as
strcoll applied to the same two strings. If overlapping occurs, the result is undefined.
Returns the length of the transformed string (not including the null character).