4.3BSD beta release manual page

[unix-history] / usr / src / lib / libc / gen / readdir.c

#ifndef lint
static char sccsid[] = "@(#)readdir.c	4.5 (Berkeley) %G%";
#endif

#include <sys/param.h>
#include <sys/dir.h>

/*
 * get next entry in a directory.
 */
struct direct *
readdir(dirp)
	register DIR *dirp;
{
	register struct direct *dp;

	for (;;) {
		if (dirp->dd_loc == 0) {
			dirp->dd_size = read(dirp->dd_fd, dirp->dd_buf, 
			    DIRBLKSIZ);
			if (dirp->dd_size <= 0)
				return NULL;
		}
		if (dirp->dd_loc >= dirp->dd_size) {
			dirp->dd_loc = 0;
			continue;
		}
		dp = (struct direct *)(dirp->dd_buf + dirp->dd_loc);
		if (dp->d_reclen <= 0 ||
		    dp->d_reclen > DIRBLKSIZ + 1 - dirp->dd_loc)
			return NULL;
		dirp->dd_loc += dp->d_reclen;
		if (dp->d_ino == 0)
			continue;
		return (dp);
	}
}