dirent/dirent.h

   1 /* Copyright (C) 1991, 92, 93, 94, 95, 96, 97 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 not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 /*
  20  *      POSIX Standard: 5.1.2 Directory Operations      <dirent.h>
  21  */
  22
  23 #ifndef _DIRENT_H
  24 #define _DIRENT_H       1
  25
  26 #include <features.h>
  27
  28 __BEGIN_DECLS
  29
  30 #include <bits/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    It defines the macro `_DIRENT_HAVE_D_TYPE' iff there is a `d_type'
  44    member that gives the type of the file.
  45  */
  46
  47 #include <bits/dirent.h>
  48
  49 #if (defined __USE_BSD || defined __USE_MISC) && !defined d_fileno
  50 # define d_ino  d_fileno                 /* Backward compatibility.  */
  51 #endif
  52
  53 /* These macros extract size information from a `struct dirent *'.
  54    They may evaluate their argument multiple times, so it must not
  55    have side effects.  Each of these may involve a relatively costly
  56    call to `strlen' on some systems, so these values should be cached.
  57
  58    _D_EXACT_NAMLEN (DP) returns the length of DP->d_name, not including
  59    its terminating null character.
  60
  61    _D_ALLOC_NAMLEN (DP) returns a size at least (_D_EXACT_NAMLEN (DP) + 1);
  62    that is, the allocation size needed to hold the DP->d_name string.
  63    Use this macro when you don't need the exact length, just an upper bound.
  64    This macro is less likely to require calling `strlen' than _D_EXACT_NAMLEN.
  65    */
  66
  67 #ifdef _DIRENT_HAVE_D_NAMLEN
  68 # define _D_EXACT_NAMLEN(d) ((d)->d_namlen)
  69 # define _D_ALLOC_NAMLEN(d) (_D_EXACT_NAMLEN (d) + 1)
  70 #else
  71 # define _D_EXACT_NAMLEN(d) (strlen ((d)->d_name))
  72 # ifdef _DIRENT_HAVE_D_RECLEN
  73 #  define _D_ALLOC_NAMLEN(d) (((char *) (d) + (d)->d_reclen) - &(d)->d_name[0])
  74 # else
  75 #  define _D_ALLOC_NAMLEN(d) (sizeof (d)->d_name > 1 ? sizeof (d)->d_name : \
  76                               _D_EXACT_NAMLEN (d) + 1)
  77 # endif
  78 #endif
  79
  80
  81 #ifdef __USE_BSD
  82 /* File types for `d_type'.  */
  83 enum
  84   {
  85     DT_UNKNOWN = 0,
  86     DT_FIFO = 1,
  87     DT_CHR = 2,
  88     DT_DIR = 4,
  89     DT_BLK = 6,
  90     DT_REG = 8,
  91     DT_LNK = 10,
  92     DT_SOCK = 12
  93   };
  94
  95 /* Convert between stat structure types and directory types.  */
  96 # define IFTODT(mode)   (((mode) & 0170000) >> 12)
  97 # define DTTOIF(dirtype)        ((dirtype) << 12)
  98 #endif
  99
 100
 101 /* This is the data type of directory stream objects.
 102    The actual structure is opaque to users.  */
 103 typedef struct __dirstream DIR;
 104
 105 /* Open a directory stream on NAME.
 106    Return a DIR stream on the directory, or NULL if it could not be opened.  */
 107 extern DIR *__opendir __P ((__const char *__name));
 108 extern DIR *opendir __P ((__const char *__name));
 109
 110 /* Close the directory stream DIRP.
 111    Return 0 if successful, -1 if not.  */
 112 extern int __closedir __P ((DIR *__dirp));
 113 extern int closedir __P ((DIR *__dirp));
 114
 115 /* Read a directory entry from DIRP.
 116    Return a pointer to a `struct dirent' describing the entry,
 117    or NULL for EOF or error.  The storage returned may be overwritten
 118    by a later readdir call on the same DIR stream.  */
 119 extern struct dirent *__readdir __P ((DIR *__dirp));
 120 extern struct dirent *readdir __P ((DIR *__dirp));
 121
 122 #if defined __USE_POSIX || defined __USE_MISC
 123 /* Reentrant version of `readdir'.  Return in RESULT a pointer to the
 124    next entry.  */
 125 extern int __readdir_r __P ((DIR *__dirp, struct dirent *__entry,
 126                              struct dirent **__result));
 127 extern int readdir_r __P ((DIR *__dirp, struct dirent *__entry,
 128                            struct dirent **__result));
 129 #endif  /* POSIX or misc */
 130
 131 /* Rewind DIRP to the beginning of the directory.  */
 132 extern void rewinddir __P ((DIR *__dirp));
 133
 134 #if defined __USE_BSD || defined __USE_MISC
 135
 136 /* Return the file descriptor used by DIRP.  */
 137 extern int dirfd __P ((DIR *__dirp));
 138
 139 # if defined __OPTIMIZE__ && defined _DIR_dirfd
 140 #  define dirfd(dirp)   _DIR_dirfd (dirp)
 141 # endif
 142
 143 # ifndef MAXNAMLEN
 144 /* Get the definitions of the POSIX.1 limits.  */
 145 #  include <bits/posix1_lim.h>
 146
 147 /* `MAXNAMLEN' is the BSD name for what POSIX calls `NAME_MAX'.  */
 148 #  ifdef NAME_MAX
 149 #   define MAXNAMLEN    NAME_MAX
 150 #  else
 151 #   define MAXNAMLEN    255
 152 #  endif
 153 # endif
 154
 155 # include <bits/types.h>
 156 # define __need_size_t
 157 # include <stddef.h>
 158
 159 /* Seek to position POS on DIRP.  */
 160 extern void seekdir __P ((DIR *__dirp, __off_t __pos));
 161
 162 /* Return the current position of DIRP.  */
 163 extern __off_t telldir __P ((DIR *__dirp));
 164
 165 /* Scan the directory DIR, calling SELECTOR on each directory entry.
 166    Entries for which SELECT returns nonzero are individually malloc'd,
 167    sorted using qsort with CMP, and collected in a malloc'd array in
 168    *NAMELIST.  Returns the number of entries selected, or -1 on error.  */
 169 extern int scandir __P ((__const char *__dir,
 170                          struct dirent ***__namelist,
 171                          int (*__selector) __P ((struct dirent *)),
 172                          int (*__cmp) __P ((__const __ptr_t,
 173                                             __const __ptr_t))));
 174
 175 /* Function to compare two `struct dirent's alphabetically.  */
 176 extern int alphasort __P ((__const __ptr_t, __const __ptr_t));
 177
 178 # ifdef __USE_GNU
 179 /* Function to compare two `struct dirent's by name & version.  */
 180 extern int versionsort __P ((__const __ptr_t, __const __ptr_t));
 181 #endif
 182
 183 /* Read directory entries from FD into BUF, reading at most NBYTES.
 184    Reading starts at offset *BASEP, and *BASEP is updated with the new
 185    position after reading.  Returns the number of bytes read; zero when at
 186    end of directory; or -1 for errors.  */
 187 extern __ssize_t __getdirentries __P ((int __fd, char *__buf,
 188                                        size_t __nbytes, __off_t *__basep));
 189 extern __ssize_t getdirentries __P ((int __fd, char *__buf,
 190                                      size_t __nbytes, __off_t *__basep));
 191
 192
 193 #endif /* Use BSD or misc.  */
 194
 195 __END_DECLS
 196
 197 #endif /* dirent.h  */