#define	BUFSIZ	512#define	_NFILE	20# ifndef FILEextern	struct	_iobuf {	char	*_ptr;	int	_cnt;	char	*_base;	char	_flag;	char	_file;} _iob[_NFILE];# endif#define	_IOREAD	01#define	_IOWRT	02#define	_IONBF	04#define	_IOMYBUF	010#define	_IOEOF	020#define	_IOERR	040#define	_IOSTRG	0100#define	_IORW	0200#define	NULL	0#define	FILE	struct _iobuf#define	EOF	(-1)#define	stdin	(&_iob[0])#define	stdout	(&_iob[1])#define	stderr	(&_iob[2])#define	getc(p)		(--(p)->_cnt>=0? *(p)->_ptr++&0377:_filbuf(p))#define	getchar()	getc(stdin)#define putc(x,p) (--(p)->_cnt>=0? ((int)(*(p)->_ptr++=(unsigned)(x))):_flsbuf((unsigned)(x),p))#define	putchar(x)	putc(x,stdout)#define	feof(p)		(((p)->_flag&_IOEOF)!=0)#define	ferror(p)	(((p)->_flag&_IOERR)!=0)#define	fileno(p)	p->_fileFILE	*fopen();FILE	*freopen();FILE	*fdopen();long	ftell();char	*fgets();