xref: /csrg-svn/lib/libc/gen/readdir.c (revision 5767)
1 /* Copyright (c) 1982 Regents of the University of California */
2 
3 static char sccsid[] = "@(#)readdir.c 1.4 02/12/82";
4 
5 #include <sys/types.h>
6 #include <ndir.h>
7 
8 /*
9  * read an old stlye directory entry and present it as a new one
10  */
11 #ifndef	DIRSIZ
12 #define	DIRSIZ	14
13 #endif
14 
15 struct	olddirect {
16 	ino_t	d_ino;
17 	char	d_name[DIRSIZ];
18 };
19 
20 /*
21  * get next entry in a directory.
22  */
23 struct direct *
24 readdir(dirp)
25 	register DIR *dirp;
26 {
27 	register struct olddirect *dp;
28 	static union {
29 		struct direct un_dir;
30 		char pad[MAXDIRSIZ];
31 	} dirun;
32 #define dir dirun.un_dir
33 
34 	for (;;) {
35 		if (dirp->dd_loc == 0) {
36 			dirp->dd_size = read(dirp->dd_fd, dirp->dd_buf,
37 			    MAXDIRSIZ);
38 			if (dirp->dd_size <= 0)
39 				return NULL;
40 		}
41 		if (dirp->dd_loc >= dirp->dd_size) {
42 			dirp->dd_loc = 0;
43 			continue;
44 		}
45 		dp = (struct olddirect *)(dirp->dd_buf + dirp->dd_loc);
46 		dirp->dd_loc += sizeof(struct olddirect);
47 		if (dp->d_ino == 0)
48 			continue;
49 		dir.d_ino = dp->d_ino;
50 		strncpy(dir.d_name, dp->d_name, DIRSIZ);
51 		dir.d_namlen = strlen(dir.d_name);
52 		dir.d_reclen = ((sizeof(struct direct) + dir.d_namlen)
53 		    + 4) & ~03;
54 		return (&dir);
55 	}
56 }
57