1 /* 2 * Copyright (c) 1983 Regents of the University of California. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms are permitted 6 * provided that the above copyright notice and this paragraph are 7 * duplicated in all such forms and that any documentation, 8 * advertising materials, and other materials related to such 9 * distribution and use acknowledge that the software was developed 10 * by the University of California, Berkeley. The name of the 11 * University may not be used to endorse or promote products derived 12 * from this software without specific prior written permission. 13 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 14 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 15 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 16 */ 17 18 #if defined(LIBC_SCCS) && !defined(lint) 19 static char sccsid[] = "@(#)readdir.c 5.4 (Berkeley) 06/18/88"; 20 #endif /* LIBC_SCCS and not lint */ 21 22 #include <sys/param.h> 23 #include <sys/dir.h> 24 25 /* 26 * get next entry in a directory. 27 */ 28 struct direct * 29 readdir(dirp) 30 register DIR *dirp; 31 { 32 register struct direct *dp; 33 34 for (;;) { 35 if (dirp->dd_loc == 0) { 36 dirp->dd_size = read(dirp->dd_fd, dirp->dd_buf, 37 DIRBLKSIZ); 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 direct *)(dirp->dd_buf + dirp->dd_loc); 46 if ((int)dp & 03) /* bogus pointer check */ 47 return NULL; 48 if (dp->d_reclen <= 0 || 49 dp->d_reclen > DIRBLKSIZ + 1 - dirp->dd_loc) 50 return NULL; 51 dirp->dd_loc += dp->d_reclen; 52 if (dp->d_ino == 0) 53 continue; 54 return (dp); 55 } 56 } 57