#include <sys/types.h>#include <sys/stat.h>/*      * read  -- read bytes from the serial port. Ignore fd, since      *          we only have stdin.      */int_read_r (r, fd, buf, nbytes)     struct _reent *r;     int fd;     char *buf;     int nbytes;{     return -1;}/*      * write -- write bytes to the serial port. Ignore fd, since      *          stdout and stderr are the same. Since we have no filesystem,      *          open will only return an error.      */int_write_r (r, fd, buf, nbytes)     struct _reent *r;     int fd;     char *buf;     int nbytes;{     return -1;}/*      * open -- open a file descriptor. We don't have a filesystem, so      *         we return an error.      */int_open_r (r, buf, flags, mode)     struct _reent *r;     char *buf;     int flags;     int mode;{     return -1;}/*      * close -- close a file descriptor. We don't need      *          to do anything, but pretend we did.      */int_close_r (ptr, fd)     struct _reent *ptr;     int fd;{     return -1;}#if 1/*      * exit      *                */void_exit ( extcode)          int extcode;{}#endif/* * sbrk -- changes heap size size. Get nbytes more *         RAM. We just increment a pointer in what's *         left of memory on the board. */char *_sbrk_r (ptr,nbytes)     struct _reent *ptr;     int nbytes;{     return NULL;}/*      * lseek -- move read/write pointer. Since a serial port      *          is non-seekable, we return an error.      */off_t_lseek_r (ptr, fd, offset, whence)     struct _reent *ptr;     int fd;     off_t offset;     int whence;{     return -1;}/*      * fstat -- get status of a file. Assume it is a      * terminal (character special file).      */int_fstat_r (r, fd, buf)     struct _reent *r;     int fd;     struct stat *buf;{     return -1;}intisatty (fd)         int fd;{  	 return fd == 0 || fd == 1 || fd == 2;}/*      * getpid -- only one process, so just return 1.      */#define __MYPID 1int_getpid (){  	return __MYPID;}/*      * kill -- go out via exit...      */int_kill (pid, sig)          int pid;          int sig;{  	 if (pid == __MYPID)    //_exit(sig);	     return 0;	 return -1;    }