1 /* 2 * Copyright (c) 1983 Regents of the University of California. 3 * All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 */ 7 8 #if defined(LIBC_SCCS) && !defined(lint) 9 static char sccsid[] = "@(#)opendir.c 5.12 (Berkeley) 03/14/92"; 10 #endif /* LIBC_SCCS and not lint */ 11 12 #include <sys/param.h> 13 #include <dirent.h> 14 #include <fcntl.h> 15 #include <stdlib.h> 16 #include <unistd.h> 17 18 long _rewinddir; 19 20 /* 21 * open a directory. 22 */ 23 DIR * 24 opendir(name) 25 const char *name; 26 { 27 register DIR *dirp; 28 register int fd; 29 30 if ((fd = open(name, 0)) == -1) 31 return NULL; 32 if (fcntl(fd, F_SETFD, 1) == -1 || 33 (dirp = (DIR *)malloc(sizeof(DIR))) == NULL) { 34 close (fd); 35 return NULL; 36 } 37 /* 38 * If CLBYTES is an exact multiple of DIRBLKSIZ, use a CLBYTES 39 * buffer that it cluster boundary aligned. 40 * Hopefully this can be a big win someday by allowing page trades 41 * to user space to be done by getdirentries() 42 */ 43 if ((CLBYTES % DIRBLKSIZ) == 0) { 44 dirp->dd_buf = malloc(CLBYTES); 45 dirp->dd_len = CLBYTES; 46 } else { 47 dirp->dd_buf = malloc(DIRBLKSIZ); 48 dirp->dd_len = DIRBLKSIZ; 49 } 50 if (dirp->dd_buf == NULL) { 51 close (fd); 52 return NULL; 53 } 54 dirp->dd_fd = fd; 55 dirp->dd_loc = 0; 56 dirp->dd_seek = 0; 57 /* 58 * Set up seek point for rewinddir. 59 */ 60 _rewinddir = telldir(dirp); 61 return dirp; 62 } 63