lib/openat.h

   1 /* provide a replacement openat function
   2    Copyright (C) 2004-2006, 2008-2024 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation, either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program 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
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  16
  17 /* written by Jim Meyering */
  18
  19 #ifndef _GL_HEADER_OPENAT
  20 #define _GL_HEADER_OPENAT
  21
  22 /* This file uses _GL_INLINE_HEADER_BEGIN, _GL_INLINE, _Noreturn,
  23    _GL_ATTRIBUTE_DEPRECATED, HAVE_OPENAT.  */
  24 #if !_GL_CONFIG_H_INCLUDED
  25  #error "Please include config.h first."
  26 #endif
  27
  28 #include <fcntl.h>
  29
  30 #include <sys/types.h>
  31 #include <sys/stat.h>
  32 #include <unistd.h>
  33
  34 _GL_INLINE_HEADER_BEGIN
  35
  36 #if !HAVE_OPENAT
  37
  38 int openat_permissive (int fd, char const *file, int flags, mode_t mode,
  39                        int *cwd_errno);
  40 bool openat_needs_fchdir (void);
  41
  42 #else
  43
  44 # define openat_permissive(Fd, File, Flags, Mode, Cwd_errno) \
  45     openat (Fd, File, Flags, Mode)
  46 # define openat_needs_fchdir() false
  47
  48 #endif
  49
  50 _Noreturn void openat_restore_fail (int);
  51 _Noreturn void openat_save_fail (int);
  52
  53 /* Using these function names makes application code
  54    slightly more readable than it would be with
  55    fchownat (..., 0) or fchownat (..., AT_SYMLINK_NOFOLLOW).  */
  56
  57 #if GNULIB_CHOWNAT
  58
  59 # ifndef CHOWNAT_INLINE
  60 #  define CHOWNAT_INLINE _GL_INLINE
  61 # endif
  62
  63 CHOWNAT_INLINE int
  64 chownat (int fd, char const *file, uid_t owner, gid_t group)
  65 {
  66   return fchownat (fd, file, owner, group, 0);
  67 }
  68
  69 CHOWNAT_INLINE int
  70 lchownat (int fd, char const *file, uid_t owner, gid_t group)
  71 {
  72   return fchownat (fd, file, owner, group, AT_SYMLINK_NOFOLLOW);
  73 }
  74
  75 #endif
  76
  77 #if GNULIB_CHMODAT
  78
  79 # ifndef CHMODAT_INLINE
  80 #  define CHMODAT_INLINE _GL_INLINE
  81 # endif
  82
  83 CHMODAT_INLINE int
  84 chmodat (int fd, char const *file, mode_t mode)
  85 {
  86   return fchmodat (fd, file, mode, 0);
  87 }
  88
  89 CHMODAT_INLINE int
  90 lchmodat (int fd, char const *file, mode_t mode)
  91 {
  92   return fchmodat (fd, file, mode, AT_SYMLINK_NOFOLLOW);
  93 }
  94
  95 #endif
  96
  97 #if GNULIB_STATAT
  98
  99 # ifndef STATAT_INLINE
 100 #  define STATAT_INLINE _GL_INLINE
 101 # endif
 102
 103 _GL_ATTRIBUTE_DEPRECATED
 104 STATAT_INLINE int
 105 statat (int fd, char const *name, struct stat *st)
 106 {
 107   return fstatat (fd, name, st, 0);
 108 }
 109
 110 _GL_ATTRIBUTE_DEPRECATED
 111 STATAT_INLINE int
 112 lstatat (int fd, char const *name, struct stat *st)
 113 {
 114   return fstatat (fd, name, st, AT_SYMLINK_NOFOLLOW);
 115 }
 116
 117 #endif
 118
 119 /* For now, there are no wrappers named laccessat or leuidaccessat,
 120    since gnulib doesn't support faccessat(,AT_SYMLINK_NOFOLLOW) and
 121    since access rights on symlinks are of limited utility.  Likewise,
 122    wrappers are not provided for accessat or euidaccessat, so as to
 123    avoid dragging in -lgen on some platforms.  */
 124
 125 _GL_INLINE_HEADER_END
 126
 127 #endif /* _GL_HEADER_OPENAT */