/* memchr function */
#include <string.h>

void *(memchr)(const void *s, int c, size_t n)
	{	/* find first occurrence of c in s[n] */
	const unsigned char uc = c;
	const unsigned char *su = (const unsigned char *)s;

	for (; 0  n; ++su, --n)
		if (*su == uc)
			return ((void *)su);
	return (NULL);
	}

