lib/mknodat.c

   1 /* Create an inode relative to an open directory.
   2    Copyright (C) 2009-2020 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 Eric Blake */
  18
  19 #include <config.h>
  20
  21 /* Specification.  */
  22 #include <sys/stat.h>
  23
  24 #include <stdlib.h>
  25
  26 #if !HAVE_MKNOD
  27
  28 # include <errno.h>
  29
  30 /* Mingw lacks mknod, so this wrapper is trivial.  */
  31
  32 int
  33 mknodat (int fd _GL_UNUSED, char const *path _GL_UNUSED,
  34          mode_t mode _GL_UNUSED, dev_t dev _GL_UNUSED)
  35 {
  36   errno = ENOSYS;
  37   return -1;
  38 }
  39
  40 #else
  41
  42 /* Create a file system node FILE relative to directory FD, with
  43    access permissions and file type in MODE, and device type in DEV.
  44    Usually, non-root applications can only create named fifos, with
  45    DEV set to 0.  If possible, create the node without changing the
  46    working directory.  Otherwise, resort to using save_cwd/fchdir,
  47    then mknod/restore_cwd.  If either the save_cwd or the restore_cwd
  48    fails, then give a diagnostic and exit nonzero.  */
  49
  50 # define AT_FUNC_NAME mknodat
  51 # define AT_FUNC_F1 mknod
  52 # define AT_FUNC_POST_FILE_PARAM_DECLS , mode_t mode, dev_t dev
  53 # define AT_FUNC_POST_FILE_ARGS        , mode, dev
  54 # include "at-func.c"
  55 # undef AT_FUNC_NAME
  56 # undef AT_FUNC_F1
  57 # undef AT_FUNC_POST_FILE_PARAM_DECLS
  58 # undef AT_FUNC_POST_FILE_ARGS
  59
  60 #endif