1 /* sendfile -- copy data directly from one file descriptor to another
2 Copyright (C) 2002-2022 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 #include <sys/sendfile.h>
20 #include <stddef.h>
21
22 /* Send COUNT bytes from file associated with IN_FD starting at OFFSET to
23 descriptor OUT_FD. */
24 ssize_t
sendfile(int out_fd,int in_fd,off_t * offset,size_t count)25 sendfile (int out_fd, int in_fd, off_t *offset, size_t count)
26 {
27 if (offset == NULL || sizeof (off_t) == sizeof (off64_t))
28 return __sendfile64 (out_fd, in_fd, (off64_t *) offset, count);
29 else
30 {
31 off64_t ofs = *offset;
32 ssize_t ret = __sendfile64 (out_fd, in_fd, &ofs, count);
33 *offset = ofs;
34 return ret;
35 }
36 }
37