newlib/libc/posix/opendir.c

   1 #ifndef HAVE_OPENDIR
   2
   3 /*
   4  * Copyright (c) 1983 Regents of the University of California.
   5  * 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. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #if defined(LIBC_SCCS) && !defined(lint)
  33 static char sccsid[] = "@(#)opendir.c   5.11 (Berkeley) 2/23/91";
  34 #endif /* LIBC_SCCS and not lint */
  35
  36 #include <dirent.h>
  37 #include <fcntl.h>
  38 #include <stdlib.h>
  39 #include <unistd.h>
  40 #include <sys/lock.h>
  41
  42 static DIR *
  43 _opendir_common(int fd)
  44 {
  45         DIR *dirp;
  46
  47         if ((dirp = (DIR *)malloc(sizeof(DIR))) == NULL) {
  48                 close (fd);
  49                 return NULL;
  50         }
  51         /*
  52          * If CLSIZE is an exact multiple of DIRBLKSIZ, use a CLSIZE
  53          * buffer that it cluster boundary aligned.
  54          * Hopefully this can be a big win someday by allowing page trades
  55          * to user space to be done by getdirentries()
  56          */
  57         dirp->dd_buf = malloc (512);
  58         dirp->dd_len = 512;
  59
  60         if (dirp->dd_buf == NULL) {
  61                 free (dirp);
  62                 close (fd);
  63                 return NULL;
  64         }
  65         dirp->dd_fd = fd;
  66         dirp->dd_loc = 0;
  67         dirp->dd_seek = 0;
  68         /*
  69          * Set up seek point for rewinddir.
  70          */
  71
  72 #ifdef HAVE_DD_LOCK
  73         /* if we have a locking mechanism, initialize it */
  74         __lock_init_recursive(dirp->dd_lock);
  75 #endif
  76
  77         return dirp;
  78 }
  79
  80 DIR *
  81 opendir(const char *name)
  82 {
  83         int fd;
  84
  85         if ((fd = open(name, O_RDONLY | O_DIRECTORY | O_CLOEXEC)) == -1)
  86                 return (NULL);
  87         return (_opendir_common(fd));
  88 }
  89
  90 DIR *
  91 fdopendir(int fd)
  92 {
  93
  94         if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
  95                 return (NULL);
  96         return (_opendir_common(fd));
  97 }
  98
  99 #endif /* ! HAVE_OPENDIR */