#include <stdio.h>

#define STR_MAX 20

void strngcpy(char *s, char *t)
{
	while (*s++ = *t++)
		;
}

int main(void)
{
	char source[] = "hello, world";
	char dest[STR_MAX];

	strngcpy( dest, source );
	printf("%s\n", dest);

	exit(0);
}