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    It defines the macro `_DIRENT_HAVE_D_OFF' iff there is a `d_off'
  41    member that gives the file offset of the next directory entry.
  42  */
  43
  44 #include <direntry.h>
  45
  46 #if (defined(__USE_BSD) || defined(__USE_MISC)) && !defined(d_fileno)
  47 #define d_ino           d_fileno                 /* Backward compatibility.  */
  48 #endif
  49
  50 /* These macros extract size information from a `struct dirent *'.
  51    They may evaluate their argument multiple times, so it must not
  52    have side effects.  Each of these may involve a relatively costly
  53    call to `strlen' on some systems, so these values should be cached.
  54
  55    _D_EXACT_NAMLEN (DP) returns the length of DP->d_name, not including
  56    its terminating null character.
  57
  58    _D_ALLOC_NAMLEN (DP) returns a size at least (_D_EXACT_NAMLEN (DP) + 1);
  59    that is, the allocation size needed to hold the DP->d_name string.
  60    Use this macro when you don't need the exact length, just an upper bound.
  61    This macro is less likely to require calling `strlen' than _D_EXACT_NAMLEN.
  62    */
  63
  64 #ifdef _DIRENT_HAVE_D_NAMLEN
  65 #define _D_EXACT_NAMLEN(d) ((d)->d_namlen)
  66 #define _D_ALLOC_NAMLEN(d) (_D_EXACT_NAMLEN (d) + 1)
  67 #else
  68 #define _D_EXACT_NAMLEN(d) (strlen ((d)->d_name))
  69 #ifdef _DIRENT_HAVE_D_RECLEN
  70 #define _D_ALLOC_NAMLEN(d) (((char *) (d) + (d)->d_reclen) - &(d)->d_name[0])
  71 #else
  72 #define _D_ALLOC_NAMLEN(d) (sizeof (d)->d_name > 1 ? sizeof (d)->d_name : \
  73                             _D_EXACT_NAMLEN (d) + 1)
  74 #endif
  75 #endif
  76
  77
  78 #ifdef __USE_BSD
  79 /* File types for `d_type'.  */
  80 enum
  81   {
  82     DT_UNKNOWN = 0,
  83     DT_FIFO = 1,
  84     DT_CHR = 2,
  85     DT_DIR = 4,
  86     DT_BLK = 6,
  87     DT_REG = 8,
  88     DT_LNK = 10,
  89     DT_SOCK = 12
  90   };
  91
  92 /* Convert between stat structure types and directory types.  */
  93 #define IFTODT(mode)    (((mode) & 0170000) >> 12)
  94 #define DTTOIF(dirtype) ((dirtype) << 12)
  95 #endif
  96
  97
  98 /* This is the data type of directory stream objects.
  99    The actual structure is opaque to users.  */
 100 typedef struct __dirstream DIR;
 101
 102 /* Open a directory stream on NAME.
 103    Return a DIR stream on the directory, or NULL if it could not be opened.  */
 104 extern DIR *opendir __P ((__const char *__name));
 105
 106 /* Close the directory stream DIRP.
 107    Return 0 if successful, -1 if not.  */
 108 extern int closedir __P ((DIR * __dirp));
 109
 110 /* Read a directory entry from DIRP.
 111    Return a pointer to a `struct dirent' describing the entry,
 112    or NULL for EOF or error.  The storage returned may be overwritten
 113    by a later readdir call on the same DIR stream.  */
 114 extern struct dirent *readdir __P ((DIR * __dirp));
 115
 116 /* Rewind DIRP to the beginning of the directory.  */
 117 extern void rewinddir __P ((DIR * __dirp));
 118
 119 #if defined(__USE_BSD) || defined(__USE_MISC)
 120
 121 /* Return the file descriptor used by DIRP.  */
 122 extern int dirfd __P ((DIR *__dirp));
 123
 124 #if defined (__OPTIMIZE__) && defined (_DIR_dirfd)
 125 #define dirfd(dirp)     _DIR_dirfd (dirp)
 126 #endif
 127
 128 #ifndef MAXNAMLEN
 129 /* Get the definitions of the POSIX.1 limits.  */
 130 #include <posix1_lim.h>
 131
 132 /* `MAXNAMLEN' is the BSD name for what POSIX calls `NAME_MAX'.  */
 133 #ifdef  NAME_MAX
 134 #define MAXNAMLEN       NAME_MAX
 135 #else
 136 #define MAXNAMLEN       255
 137 #endif
 138 #endif
 139
 140 #include <gnu/types.h>
 141 #define __need_size_t
 142 #include <stddef.h>
 143
 144 /* Seek to position POS on DIRP.  */
 145 extern void seekdir __P ((DIR * __dirp, __off_t __pos));
 146
 147 /* Return the current position of DIRP.  */
 148 extern __off_t telldir __P ((DIR * __dirp));
 149
 150 /* Scan the directory DIR, calling SELECT on each directory entry.
 151    Entries for which SELECT returns nonzero are individually malloc'd,
 152    sorted using qsort with CMP, and collected in a malloc'd array in
 153    *NAMELIST.  Returns the number of entries selected, or -1 on error.  */
 154 extern int scandir __P ((__const char *__dir,
 155                          struct dirent ***__namelist,
 156                          int (*__select) __P ((struct dirent *)),
 157                          int (*__cmp) __P ((__const __ptr_t,
 158                                             __const __ptr_t))));
 159
 160 /* Function to compare two `struct dirent's alphabetically.  */
 161 extern int alphasort __P ((__const __ptr_t, __const __ptr_t));
 162
 163
 164 /* Read directory entries from FD into BUF, reading at most NBYTES.
 165    Reading starts at offset *BASEP, and *BASEP is updated with the new
 166    position after reading.  Returns the number of bytes read; zero when at
 167    end of directory; or -1 for errors.  */
 168 extern __ssize_t __getdirentries __P ((int __fd, char *__buf,
 169                                        size_t __nbytes, __off_t *__basep));
 170 extern __ssize_t getdirentries __P ((int __fd, char *__buf,
 171                                      size_t __nbytes, __off_t *__basep));
 172
 173
 174 #endif /* Use BSD or misc.  */
 175
 176 __END_DECLS
 177
 178 #endif /* dirent.h  */