Example of sorting by ASCII char code

simplesort.c

#include <stdbool.h>
#include <stdio.h>
#include <string.h>
 
#define ASIZE 50

char arr[(ASIZE + 1)];

bool k_cmp_chr(char c1, char c2)
{
	if(c1 > c2) return true;
	return false;
}
 
char * k_sort_string(char *str)
{
	bool has_changed = false;
	size_t len = strnlen(str, ASIZE);
	for(int i = 0; i < len; ++i)
	{
		char c1 = *(str + i);
		char c2 = *(str + (i + 1));
		
		if(c1 == '\0') break;
		if(c2 == '\0') c2 = c1;
		
		if(k_cmp_chr(c1, c2))
		{
			if(!has_changed) has_changed = true;
			arr[i] = c2;
			arr[i + 1] = c1;
			++i;
			continue;
		}
		arr[i] = c1;
	}
	if(has_changed) return k_sort_string(arr);
	
	return arr;
}

int main(void)
{
	char *str_to_sort_desc = "gfedcba";
	char *str_to_sort_asce = "abcdefg";
	char *ss = "sort this string all kinds of crazy";
	printf("sorted string=%s\n", k_sort_string(ss));
	return 0;
}