io/sys/sendfile.h

   1 /* sendfile -- copy data directly from one file descriptor to another
   2    Copyright (C) 1998-2019 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the 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    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _SYS_SENDFILE_H
  20 #define _SYS_SENDFILE_H 1
  21
  22 #include <features.h>
  23 #include <sys/types.h>
  24
  25 __BEGIN_DECLS
  26
  27 /* Send up to COUNT bytes from file associated with IN_FD starting at
  28    *OFFSET to descriptor OUT_FD.  Set *OFFSET to the IN_FD's file position
  29    following the read bytes.  If OFFSET is a null pointer, use the normal
  30    file position instead.  Return the number of written bytes, or -1 in
  31    case of error.  */
  32 #ifndef __USE_FILE_OFFSET64
  33 extern ssize_t sendfile (int __out_fd, int __in_fd, off_t *__offset,
  34                          size_t __count) __THROW;
  35 #else
  36 # ifdef __REDIRECT_NTH
  37 extern ssize_t __REDIRECT_NTH (sendfile,
  38                                (int __out_fd, int __in_fd, __off64_t *__offset,
  39                                 size_t __count), sendfile64);
  40 # else
  41 #  define sendfile sendfile64
  42 # endif
  43 #endif
  44 #ifdef __USE_LARGEFILE64
  45 extern ssize_t sendfile64 (int __out_fd, int __in_fd, __off64_t *__offset,
  46                            size_t __count) __THROW;
  47 #endif
  48
  49 __END_DECLS
  50
  51 #endif  /* sys/sendfile.h */