#include <stdio.h>
#include <string.h>
#include <locale.h>

char (*sort_words(char (*words)[80], int size, char *locale ))[80] {
	int i;
	int n = size;
	char temp[80];
	short int sorted = 1;

	setlocale(LC_COLLATE, locale);

	while(sorted) {
		sorted = 0;
		for (i=0; i<n-1; i++) {
			if ( strcoll(words[i], words[i+1]) > 0 ) {
				sorted = 1;
				strcpy(temp, words[i]);
				strcpy(words[i], words[i+1]);
				strcpy(words[i+1], temp);
			}
		}
	}
	return words;
}

#include <stdio.h>
#include <string.h>
#include <locale.h>

char (*sort_words(char (*words)[80], int size, char *locale ))[80] {
	int i;
	int n = size;
	char temp[80];
	short int sorted = 1;

	setlocale(LC_COLLATE, locale);

	while(sorted) {
		sorted = 0;
		for (i=0; i<n-1; i++) {
			if ( strcoll(words[i], words[i+1]) > 0 ) {
				sorted = 1;
				strcpy(temp, words[i]);
				strcpy(words[i], words[i+1]);
				strcpy(words[i+1], temp);
			}
		}
	}
	return words;
}

int main(void) {
	char test[10][80] = {
			"Apple", "Mango",
			"Яблоко", "Слива", "Груша", "арбуз", "Лимон",
			"Cherry", "blueberry", "Strawberry"
	};
	int n = 10;
	char locale[] = "en_US.UTF-8";
	//char locale[] = "C"

	char (*ptr)[80];

	ptr = sort_words(test, n, locale);

	for (int i=0; i<n; i++) {
		printf("%s\n", ptr[i]);
	}
}

Apple
blueberry
Cherry
Mango
Strawberry
арбуз
Груша
Лимон
Слива
Яблоко