newlib/libc/sys/sysvi386/opendir.c

   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, 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. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #if defined(LIBC_SCCS) && !defined(lint)
  31 static char sccsid[] = "@(#)opendir.c   5.11 (Berkeley) 2/23/91";
  32 #endif /* LIBC_SCCS and not lint */
  33
  34 #include <dirent.h>
  35 #include <fcntl.h>
  36 #include <stdlib.h>
  37 #include <unistd.h>
  38
  39 /*
  40  * open a directory.
  41  */
  42 DIR *
  43 opendir(name)
  44         const char *name;
  45 {
  46         register DIR *dirp;
  47         register int fd;
  48
  49         if ((fd = open(name, 0)) == -1)
  50                 return NULL;
  51         if (fcntl(fd, F_SETFD, 1) == -1 ||
  52             (dirp = (DIR *)malloc(sizeof(DIR))) == NULL) {
  53                 close (fd);
  54                 return NULL;
  55         }
  56         /*
  57          * If CLSIZE is an exact multiple of DIRBLKSIZ, use a CLSIZE
  58          * buffer that it cluster boundary aligned.
  59          * Hopefully this can be a big win someday by allowing page trades
  60          * to user space to be done by getdirentries()
  61          */
  62         dirp->dd_buf = malloc (512);
  63         dirp->dd_len = 512;
  64
  65         if (dirp->dd_buf == NULL) {
  66                 close (fd);
  67                 return NULL;
  68         }
  69         dirp->dd_fd = fd;
  70         dirp->dd_loc = 0;
  71         dirp->dd_seek = 0;
  72         /*
  73          * Set up seek point for rewinddir.
  74          */
  75         return dirp;
  76 }