1 /* $NetBSD: opendir.c,v 1.1 1999/05/19 03:53:03 gwr Exp $ */ 2 3 /* 4 * Copyright (c) 1983, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/param.h> 37 #include <sys/mount.h> 38 #include <sys/stat.h> 39 40 #include <dirent.h> 41 #include <errno.h> 42 #include <fcntl.h> 43 #include <stdlib.h> 44 #include <string.h> 45 #include <unistd.h> 46 47 /* 48 * Open a directory. 49 */ 50 DIR * 51 opendir(name) 52 const char *name; 53 { 54 DIR *dirp; 55 int fd; 56 struct stat sb; 57 int pagesz; 58 59 if ((fd = open(name, O_RDONLY | O_NONBLOCK)) == -1) 60 return (NULL); 61 if (fstat(fd, &sb) || !S_ISDIR(sb.st_mode)) { 62 errno = ENOTDIR; 63 close(fd); 64 return (NULL); 65 } 66 if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1 || 67 (dirp = (DIR *)malloc(sizeof(DIR))) == NULL) { 68 close(fd); 69 return (NULL); 70 } 71 72 /* 73 * Determine whether this directory is the top of a union stack. 74 * (Never is on a ramdisk) 75 */ 76 { 77 dirp->dd_len = DIRBLKSIZ; 78 dirp->dd_buf = malloc((size_t)dirp->dd_len); 79 if (dirp->dd_buf == NULL) { 80 free(dirp); 81 close (fd); 82 return (NULL); 83 } 84 dirp->dd_seek = 0; 85 } 86 87 dirp->dd_loc = 0; 88 dirp->dd_fd = fd; 89 dirp->dd_flags = DTF_HIDEW; 90 91 /* 92 * Set up seek point for rewinddir. 93 */ 94 dirp->dd_rewind = telldir(dirp); 95 96 return (dirp); 97 } 98