dirent/dirent.h

   1 /* Copyright (C) 1991, 92, 93, 94, 95, 96 Free Software Foundation, Inc.
   2 This file is part of the GNU C Library.
   3
   4 The GNU C Library is free software; you can redistribute it and/or
   5 modify it under the terms of the GNU Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 License, or (at your option) any later version.
   8
   9 The GNU C Library is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 /*
  20  *      POSIX Standard: 5.1.2 Directory Operations      <dirent.h>
  21  */
  22
  23 #ifndef _DIRENT_H
  24
  25 #define _DIRENT_H       1
  26 #include <features.h>
  27
  28 __BEGIN_DECLS
  29
  30 #include <gnu/types.h>
  31
  32 /* This file defines `struct dirent'.
  33
  34    It defines the macro `_DIRENT_HAVE_D_NAMLEN' iff there is a `d_namlen'
  35    member that gives the length of `d_name'.
  36
  37    It defines the macro `_DIRENT_HAVE_D_RECLEN' iff there is a `d_reclen'
  38    member that gives the size of the entire directory entry.  */
  39
  40 #include <direntry.h>
  41
  42 #if defined(__USE_BSD) || defined(__USE_MISC)
  43 #define d_ino           d_fileno /* Backward compatibility.  */
  44 #endif
  45
  46 /* These macros extract size information from a `struct dirent *'.
  47    They may evaluate their argument multiple times, so it must not
  48    have side effects.  Each of these may involve a relatively costly
  49    call to `strlen' on some systems, so these values should be cached.
  50
  51    _D_EXACT_NAMLEN (DP) returns the length of DP->d_name, not including
  52    its terminating null character.
  53
  54    _D_ALLOC_NAMLEN (DP) returns a size at least (_D_EXACT_NAMLEN (DP) + 1);
  55    that is, the allocation size needed to hold the DP->d_name string.
  56    Use this macro when you don't need the exact length, just an upper bound.
  57    This macro is less likely to require calling `strlen' than _D_EXACT_NAMLEN.
  58    */
  59
  60 #ifdef _DIRENT_HAVE_D_NAMLEN
  61 #define _D_EXACT_NAMLEN(d) ((d)->d_namlen)
  62 #define _D_ALLOC_NAMLEN(d) (_D_EXACT_NAMLEN (d) + 1)
  63 #else
  64 #define _D_EXACT_NAMLEN(d) (strlen ((d)->d_name))
  65 #ifdef _DIRENT_HAVE_D_RECLEN
  66 #define _D_ALLOC_NAMLEN(d) (((char *) (d) + (d)->d_reclen) - &(d)->d_name[0])
  67 #else
  68 #define _D_ALLOC_NAMLEN(d) (sizeof (d)->d_name > 1 ? sizeof (d)->d_name : \
  69                             _D_EXACT_NAMLEN (d) + 1)
  70 #endif
  71 #endif
  72
  73
  74 #ifdef __USE_BSD
  75 /* File types for `d_type'.  */
  76 enum
  77   {
  78     DT_UNKNOWN = 0,
  79     DT_FIFO = 1,
  80     DT_CHR = 2,
  81     DT_DIR = 4,
  82     DT_BLK = 6,
  83     DT_REG = 8,
  84     DT_LNK = 10,
  85     DT_SOCK = 12
  86   };
  87
  88 /* Convert between stat structure types and directory types.  */
  89 #define IFTODT(mode)    (((mode) & 0170000) >> 12)
  90 #define DTTOIF(dirtype) ((dirtype) << 12)
  91 #endif
  92
  93
  94 /* This is the data type of directory stream objects.
  95    The actual structure is opaque to users.  */
  96 typedef struct __dirstream DIR;
  97
  98 /* Open a directory stream on NAME.
  99    Return a DIR stream on the directory, or NULL if it could not be opened.  */
 100 extern DIR *opendir __P ((__const char *__name));
 101
 102 /* Close the directory stream DIRP.
 103    Return 0 if successful, -1 if not.  */
 104 extern int closedir __P ((DIR * __dirp));
 105
 106 /* Read a directory entry from DIRP.
 107    Return a pointer to a `struct dirent' describing the entry,
 108    or NULL for EOF or error.  The storage returned may be overwritten
 109    by a later readdir call on the same DIR stream.  */
 110 extern struct dirent *readdir __P ((DIR * __dirp));
 111
 112 /* Rewind DIRP to the beginning of the directory.  */
 113 extern void rewinddir __P ((DIR * __dirp));
 114
 115 #if defined(__USE_BSD) || defined(__USE_MISC)
 116
 117 /* Return the file descriptor used by DIRP.  */
 118 extern int dirfd __P ((DIR *__dirp));
 119
 120 #if defined (__OPTIMIZE__) && defined (_DIR_dirfd)
 121 #define dirfd(dirp)     _DIR_dirfd (dirp)
 122 #endif
 123
 124 #ifndef MAXNAMLEN
 125 /* Get the definitions of the POSIX.1 limits.  */
 126 #include <posix1_lim.h>
 127
 128 /* `MAXNAMLEN' is the BSD name for what POSIX calls `NAME_MAX'.  */
 129 #ifdef  NAME_MAX
 130 #define MAXNAMLEN       NAME_MAX
 131 #else
 132 #define MAXNAMLEN       255
 133 #endif
 134 #endif
 135
 136 #include <gnu/types.h>
 137 #define __need_size_t
 138 #include <stddef.h>
 139
 140 /* Seek to position POS on DIRP.  */
 141 extern void seekdir __P ((DIR * __dirp, __off_t __pos));
 142
 143 /* Return the current position of DIRP.  */
 144 extern __off_t telldir __P ((DIR * __dirp));
 145
 146 /* Scan the directory DIR, calling SELECT on each directory entry.
 147    Entries for which SELECT returns nonzero are individually malloc'd,
 148    sorted using qsort with CMP, and collected in a malloc'd array in
 149    *NAMELIST.  Returns the number of entries selected, or -1 on error.  */
 150 extern int scandir __P ((__const char *__dir,
 151                          struct dirent ***__namelist,
 152                          int (*__select) __P ((struct dirent *)),
 153                          int (*__cmp) __P ((__const __ptr_t,
 154                                             __const __ptr_t))));
 155
 156 /* Function to compare two `struct dirent's alphabetically.  */
 157 extern int alphasort __P ((__const __ptr_t, __const __ptr_t));
 158
 159
 160 /* Read directory entries from FD into BUF, reading at most NBYTES.
 161    Reading starts at offset *BASEP, and *BASEP is updated with the new
 162    position after reading.  Returns the number of bytes read; zero when at
 163    end of directory; or -1 for errors.  */
 164 extern __ssize_t __getdirentries __P ((int __fd, char *__buf,
 165                                        size_t __nbytes, __off_t *__basep));
 166 extern __ssize_t getdirentries __P ((int __fd, char *__buf,
 167                                      size_t __nbytes, __off_t *__basep));
 168
 169
 170 #endif /* Use BSD or misc.  */
 171
 172 __END_DECLS
 173
 174 #endif /* dirent.h  */