misc.h

this is very good for teacher

#ifndef _MISC_H_
#define _MISC_H_

/* Copy one word once and then copy one byte once. */
#define MEMCPY_PLUS_PLUS(dest, src, n) \
do {												\
	void *__end = (char *)(dest) + n;				\
	while ((long *)(dest) + 1 <= (long *)__end)		\
		*((long *)(dest))++ = *((long *)(src))++;	\
	while ((char *)(dest) + 1 <= (char *)__end)		\
		*((char *)(dest))++ = *((char *)(src))++;	\
} while (0)

#define MEMCPY_PLUS(dest, src, n)					\
do {												\
	const void *__src = (src);						\
	MEMCPY_PLUS_PLUS(dest, __src, n);				\
} while (0)

#ifdef __cplusplus
extern "C"
{
#endif

char *strdupn(const char *string, unsigned int len);

#ifdef __cplusplus
}
#endif

#endif