io/lseek.c

   1 /* Copyright (C) 1991-2015 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 Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the 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    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <unistd.h>
  20 #include <sys/types.h>
  21
  22 /* Seek to OFFSET on FD, starting from WHENCE.  */
  23 off_t
  24 __libc_lseek (fd, offset, whence)
  25      int fd;
  26      off_t offset;
  27      int whence;
  28 {
  29   if (fd < 0)
  30     {
  31       __set_errno (EBADF);
  32       return -1;
  33     }
  34   switch (whence)
  35     {
  36     case SEEK_SET:
  37     case SEEK_CUR:
  38     case SEEK_END:
  39       break;
  40     default:
  41       __set_errno (EINVAL);
  42       return -1;
  43     }
  44
  45   __set_errno (ENOSYS);
  46   return -1;
  47 }
  48 weak_alias (__libc_lseek, __lseek)
  49 weak_alias (__libc_lseek, lseek)
  50 stub_warning (lseek)
  51
  52 libc_hidden_def (__lseek)