1 /*
2  * Copyright (c) 2006 Darren Tucker
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include "includes.h"
18 
19 #include <sys/types.h>
20 #include <sys/stat.h>
21 
22 #include <fcntl.h>
23 #include <stdio.h>
24 #include <stdlib.h>
25 #include <unistd.h>
26 
27 #define NUM_OPENS 10
28 
29 void
30 fail(char *msg)
31 {
32 	fprintf(stderr, "closefrom: %s\n", msg);
33 	exit(1);
34 }
35 
36 int
37 main(void)
38 {
39 	int i, max, fds[NUM_OPENS];
40 	char buf[512];
41 
42 	for (i = 0; i < NUM_OPENS; i++)
43 		if ((fds[i] = open("/dev/null", O_RDONLY)) == -1)
44 			exit(0);	/* can't test */
45 	max = i - 1;
46 
47 	/* should close last fd only */
48 	closefrom(fds[max]);
49 	if (close(fds[max]) != -1)
50 		fail("failed to close highest fd");
51 
52 	/* make sure we can still use remaining descriptors */
53 	for (i = 0; i < max; i++)
54 		if (read(fds[i], buf, sizeof(buf)) == -1)
55 			fail("closed descriptors it should not have");
56 
57 	/* should close all fds */
58 	closefrom(fds[0]);
59 	for (i = 0; i < NUM_OPENS; i++)
60 		if (close(fds[i]) != -1)
61 			fail("failed to close from lowest fd");
62 	return 0;
63 }
64