1 /* 2 * Copyright (c) 1983, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #if defined(LIBC_SCCS) && !defined(lint) 35 /*static char sccsid[] = "from: @(#)opendir.c 8.2 (Berkeley) 2/12/94";*/ 36 static char rcsid[] = "$Id: opendir.c,v 1.4 1994/09/15 10:48:51 pk Exp $"; 37 #endif /* LIBC_SCCS and not lint */ 38 39 #include <sys/param.h> 40 #include <sys/types.h> 41 #include <sys/stat.h> 42 #include <dirent.h> 43 #include <fcntl.h> 44 #include <stdlib.h> 45 #include <unistd.h> 46 #include <errno.h> 47 48 /* 49 * open a directory. 50 */ 51 DIR * 52 opendir(name) 53 const char *name; 54 { 55 struct stat statb; 56 register DIR *dirp; 57 register int fd; 58 register int pagesz; 59 60 if ((fd = open(name, 0)) == -1) 61 return NULL; 62 if (fstat(fd, &statb) || !S_ISDIR(statb.st_mode)) { 63 errno = ENOTDIR; 64 close (fd); 65 return NULL; 66 } 67 if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1 || 68 (dirp = (DIR *)malloc(sizeof(DIR))) == NULL) { 69 close (fd); 70 return NULL; 71 } 72 /* 73 * If the machine's page size is an exact multiple of DIRBLKSIZ, 74 * use a buffer that is cluster boundary aligned. 75 * Hopefully this can be a big win someday by allowing page trades 76 * to user space to be done by getdirentries() 77 */ 78 if (((pagesz = getpagesize()) % DIRBLKSIZ) == 0) 79 dirp->dd_len = pagesz; 80 else 81 dirp->dd_len = DIRBLKSIZ; 82 83 dirp->dd_buf = malloc(dirp->dd_len); 84 if (dirp->dd_buf == NULL) { 85 close (fd); 86 return NULL; 87 } 88 dirp->dd_fd = fd; 89 dirp->dd_loc = 0; 90 dirp->dd_seek = 0; 91 /* 92 * Set up seek point for rewinddir. 93 */ 94 dirp->dd_rewind = telldir(dirp); 95 return dirp; 96 } 97