strxfrm() - transform a string under locale
#include <string.h>
size_t strxfrm (char *dst, const char *src, size_t n)
The strxfrm(3) function transforms a string, src, to the current locale and stores at most n bytes of it in dst. The transformed string will still compare properly
This function is a subset of strcoll(3)'s functionality, and is primarily a tool for efficient comparisons. When many comparisons must be made, using strxfrm(3) and strcmp(3) can be faster than using strcoll(3).
In the C and POSIX locales, it is nearly identical to strncmp(3), but the return value is different.
strxfrm(3) returns the length of the transformed string.
memcmp(3)
strcasecmp(3)
strcmp(3)
strcoll(3)