sysdeps/mach/hurd/symlink.c

   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 #include <ansidecl.h>
  20 #include <string.h>
  21 #include <unistd.h>
  22 #include <hurd.h>
  23 #include <hurd/paths.h>
  24 #include <fcntl.h>
  25
  26 /* Make a link to FROM called TO.  */
  27 int
  28 DEFUN(__symlink, (from, to), CONST char *from AND CONST char *to)
  29 {
  30   error_t err;
  31   file_t dir, node;
  32   char *name;
  33   const size_t len = strlen (from) + 1;
  34   char buf[sizeof (_HURD_SYMLINK) + len];
  35
  36   /* A symlink is a file whose translator is "/hurd/symlink\0target\0".  */
  37
  38   memcpy (buf, _HURD_SYMLINK, sizeof (_HURD_SYMLINK));
  39   memcpy (&buf[sizeof (_HURD_SYMLINK)], from, len);
  40
  41   dir = __file_name_split (to, &name);
  42   if (dir == MACH_PORT_NULL)
  43     return -1;
  44
  45   /* Create a new, unlinked node in the target directory.  */
  46   err = __dir_mkfile (dir, O_WRITE, 0777 & ~_hurd_umask, &node);
  47
  48   if (! err)
  49     /* Set the node's translator to make it a symlink.  */
  50     err = __file_set_translator (node,
  51                                  FS_TRANS_EXCL|FS_TRANS_SET,
  52                                  FS_TRANS_EXCL|FS_TRANS_SET, 0,
  53                                  buf, sizeof (_HURD_SYMLINK) + len,
  54                                  MACH_PORT_NULL, MACH_MSG_TYPE_COPY_SEND);
  55
  56   if (! err)
  57     /* Link the node, now a valid symlink, into the target directory.  */
  58     err = __dir_link (dir, node, name, 1);
  59
  60   __mach_port_deallocate (__mach_task_self (), dir);
  61   __mach_port_deallocate (__mach_task_self (), node);
  62
  63   if (err)
  64     return __hurd_fail (err);
  65   return 0;
  66 }
  67
  68 weak_alias (__symlink, symlink)