sysdeps/unix/sysv/linux/i386/pread.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
  23 #include <sysdep.h>
  24 #include <sys/syscall.h>
  25
  26 #ifdef __NR_pread
  27
  28 static ssize_t __emulate_pread (int fd, void *buf, size_t count,
  29                                 off_t offset) internal_function;
  30
  31
  32 ssize_t
  33 __pread (fd, buf, count, offset)
  34      int fd;
  35      void *buf;
  36      size_t count;
  37      off_t offset;
  38 {
  39   ssize_t result;
  40
  41   /* First try the syscall.  */
  42   result = INLINE_SYSCALL (pread, 5, fd, buf, count, offset, 0);
  43   if (result == -1 && errno == ENOSYS)
  44     /* No system call available.  Use the emulation.  */
  45     result = __emulate_pread (fd, buf, count, offset);
  46
  47   return result;
  48 }
  49
  50 weak_alias (__pread, pread)
  51
  52 #define __pread(fd, buf, count, offset) \
  53      static internal_function __emulate_pread (fd, buf, count, offset)
  54 #endif
  55 #include <sysdeps/posix/pread.c>