int copyfile_mode(const char *from, const char *to, mode_t mode)
{
int fromfd, tofd;
struct stat st;
int err = -1;
char *tmp = NULL, *ptr = NULL;
if (stat(from, &st))
goto out;
/* extra 'x' at the end is to reserve space for '.' */
if (asprintf(&tmp, "%s.XXXXXXx", to) < 0) {
tmp = NULL;
goto out;
}
ptr = strrchr(tmp, '/');
if (!ptr)
goto out;
ptr = memmove(ptr + 1, ptr, strlen(ptr) - 1);
*ptr = '.';
tofd = mkstemp(tmp);
if (tofd < 0)
goto out;
if (fchmod(tofd, mode))
goto out_close_to;
if (st.st_size == 0) { /* /proc? do it slowly... */
err = slow_copyfile(from, tmp);
goto out_close_to;
}
fromfd = open(from, O_RDONLY);
if (fromfd < 0)
goto out_close_to;
err = copyfile_offset(fromfd, 0, tofd, 0, st.st_size);
close(fromfd);
out_close_to:
close(tofd);
if (!err)
err = link(tmp, to);
unlink(tmp);
out:
free(tmp);
return err;
}
int copyfile(const char *from, const char *to)
{
int fromfd, tofd;
struct stat st;
void *addr;
int err = -1;
if (stat(from, &st))
goto out;
if (st.st_size == 0) /* /proc? do it slowly... */
return slow_copyfile(from, to);
fromfd = open(from, O_RDONLY);
if (fromfd < 0)
goto out;
tofd = creat(to, 0755);
if (tofd < 0)
goto out_close_from;
addr = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fromfd, 0);
if (addr == MAP_FAILED)
goto out_close_to;
if (write(tofd, addr, st.st_size) == st.st_size)
err = 0;
munmap(addr, st.st_size);
out_close_to:
close(tofd);
if (err)
unlink(to);
out_close_from:
close(fromfd);
out:
return err;
}
