1/* Copy a file from one path to another.
2 Copyright (C) 2020-2023 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 <fcntl.h>
20#include <support/check.h>
21#include <support/support.h>
22#include <support/xunistd.h>
23
24void
25support_copy_file (const char *from, const char *to)
26{
27 struct stat st;
28 xstat (from, &st);
29 int fd_from = xopen (from, O_RDONLY, 0);
30 mode_t mode = st.st_mode & 0777;
31 int fd_to = xopen (to, O_WRONLY | O_TRUNC | O_CREAT, mode);
32 ssize_t ret = support_copy_file_range (fd_from, NULL, fd_to, NULL,
33 st.st_size, 0);
34 if (ret < 0)
35 FAIL_EXIT1 ("copying from \"%s\" to \"%s\": %m", from, to);
36 if (ret != st.st_size)
37 FAIL_EXIT1 ("copying from \"%s\" to \"%s\": only %zd of %llu bytes copied",
38 from, to, ret, (unsigned long long int) st.st_size);
39 if (fchmod (fd_to, mode) < 0)
40 FAIL_EXIT1 ("fchmod on %s to 0%o: %m", to, mode);
41 xclose (fd_to);
42 xclose (fd_from);
43}
44