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

char *toLower(const char *str);

int main(void)
{
	char str[]="HELLO, WORLD", *strp;

	printf("Before toLower (%s)\n", str);
	strp = toLower(str);
	printf("After  toLower (%s)\n", strp);

	return 0;
}

char *toLower(const char *str)
{
	char *retp = (char *)malloc(strlen(str)), *retp0;

	retp0 = retp;

	while(*str) {
		if ( 'A' <= *str && *str <= 'Z' ) {
			*retp += 0x20 + *str;
		} else {
			*retp = *str;
		}
		retp++; str++;
	}
	return retp0;
}