sysdeps/unix/sysv/linux/pwrite.c

   1 /* Copyright (C) 1997, 1998 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <errno.h>
  21 #include <unistd.h>
  22 #include <sys/syscall.h>
  23
  24 #ifdef __NR_pwrite
  25
  26 extern ssize_t __syscall_pwrite64 (int fd, const void *buf, size_t count,
  27                                    off_t offset_hi, off_t offset_lo);
  28
  29 static ssize_t __emulate_pwrite (int fd, const void *buf, size_t count,
  30                                  off_t offset) internal_function;
  31
  32
  33 ssize_t
  34 __pwrite (fd, buf, count, offset)
  35      int fd;
  36      const void *buf;
  37      size_t count;
  38      off_t offset;
  39 {
  40   ssize_t result;
  41
  42   /* First try the syscall.  */
  43   result = __syscall_pwrite64 (fd, buf, count, 0, offset);
  44   if (result == -1 && errno == ENOSYS)
  45     /* No system call available.  Use the emulation.  */
  46     result = __emulate_pwrite (fd, buf, count, offset);
  47
  48   return result;
  49 }
  50
  51 weak_alias (__pwrite, pwrite)
  52
  53 #define __pwrite(fd, buf, count, offset) \
  54      static internal_function __emulate_pwrite (fd, buf, count, offset)
  55 #endif
  56 #include <sysdeps/posix/pwrite.c>