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/*
* Copyright © 2015 Guillem Jover <guillem@hadrons.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
int
main(int argc, char *argv[])
{
int i;
int fd;
int fd_max;
fd = open("/dev/null", O_RDONLY);
fd_max = 1024;
/* First make sure we have a clean fd list. */
for (i = 4; i < fd_max; i++)
close(i);
/* Then initialize each even fd. */
for (i = 4; i < fd_max; i *= 2) {
int fd_new = dup2(fd, i);
if (fd_new < 0 && (errno == EMFILE || errno == EBADF)) {
fd_max = i - 1;
break;
}
assert(fd_new == i);
}
if (fd < 4)
close(fd);
closefrom(4);
for (i = 4; i < fd_max; i++) {
int rc;
errno = 0;
rc = fcntl(i, F_GETFD);
#ifdef __APPLE__
/* On macOS we only set close-on-exec. */
if ((i & (i - 1)) == 0)
assert(rc == FD_CLOEXEC);
else
assert(rc == -1 && errno == EBADF);
#else
assert(rc == -1 && errno == EBADF);
#endif
}
assert(fcntl(fd, F_GETFL) == -1 && errno == EBADF);
return 0;
}
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