1 /* 2 * Copyright (c) 1983, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 */ 7 8 #if defined(LIBC_SCCS) && !defined(lint) 9 static char sccsid[] = "@(#)opendir.c 8.2 (Berkeley) 02/12/94"; 10 #endif /* LIBC_SCCS and not lint */ 11 12 #include <sys/param.h> 13 14 #include <dirent.h> 15 #include <fcntl.h> 16 #include <stdlib.h> 17 #include <unistd.h> 18 19 /* 20 * open a directory. 21 */ 22 DIR * 23 opendir(name) 24 const char *name; 25 { 26 register DIR *dirp; 27 register int fd; 28 29 if ((fd = open(name, 0)) == -1) 30 return NULL; 31 if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1 || 32 (dirp = (DIR *)malloc(sizeof(DIR))) == NULL) { 33 close (fd); 34 return NULL; 35 } 36 /* 37 * If CLBYTES is an exact multiple of DIRBLKSIZ, use a CLBYTES 38 * buffer that it cluster boundary aligned. 39 * Hopefully this can be a big win someday by allowing page trades 40 * to user space to be done by getdirentries() 41 */ 42 if ((CLBYTES % DIRBLKSIZ) == 0) { 43 dirp->dd_buf = malloc(CLBYTES); 44 dirp->dd_len = CLBYTES; 45 } else { 46 dirp->dd_buf = malloc(DIRBLKSIZ); 47 dirp->dd_len = DIRBLKSIZ; 48 } 49 if (dirp->dd_buf == NULL) { 50 close (fd); 51 return NULL; 52 } 53 dirp->dd_fd = fd; 54 dirp->dd_loc = 0; 55 dirp->dd_seek = 0; 56 /* 57 * Set up seek point for rewinddir. 58 */ 59 dirp->dd_rewind = telldir(dirp); 60 return dirp; 61 } 62