/*
	readdir -- read next entry from a directory stream

	last edit:	25-Apr-1987	D A Gwyn
*/

#include	<errno.h>
#include	<sys/errno.h>
#include	<sys/types.h>
#include	<dirent.h>

/* SVR3 system call, or emulation for getdents() */
extern int getdents(int fildes, char *buf, unsigned nbyte);

#ifndef NULL
#define	NULL	0
#endif

struct dirent *
readdir(register DIR *dirp)
{
	register struct dirent	*dp;	/* -> directory data */

	if ( dirp == NULL || dirp->dd_buf == NULL )
		{
		errno = EFAULT;
		return NULL;		/* invalid pointer */
		}

	do	{
		if ( dirp->dd_loc >= dirp->dd_size )	/* empty or obsolete */
			dirp->dd_loc = dirp->dd_size = 0;

		if ( dirp->dd_size == 0	/* need to refill buffer */
		  && (dirp->dd_size =
			getdents( dirp->dd_fd, dirp->dd_buf, (unsigned)DIRBUF )
		     ) <= 0
		   )
			return NULL;	/* EOF or error */

		dp = (struct dirent *)&dirp->dd_buf[dirp->dd_loc];
		dirp->dd_loc += dp->d_reclen;
		}
	while ( dp->d_ino == 0L );	/* don't rely on getdents() */

	return dp;
}