xref: /freebsd/lib/libopenbsd/getdtablecount.c (revision a2f733abcff64628b7771a47089628b7327a88bd)
1*1bbc47cbSCraig Rodrigues /*-
2*1bbc47cbSCraig Rodrigues  * Copyright (c) 2015 Craig Rodrigues
3*1bbc47cbSCraig Rodrigues  * All rights reserved.
4*1bbc47cbSCraig Rodrigues  *
5*1bbc47cbSCraig Rodrigues  * Redistribution and use in source and binary forms, with or without
6*1bbc47cbSCraig Rodrigues  * modification, are permitted provided that the following conditions
7*1bbc47cbSCraig Rodrigues  * are met:
8*1bbc47cbSCraig Rodrigues  * 1. Redistributions of source code must retain the above copyright
9*1bbc47cbSCraig Rodrigues  *    notice, this list of conditions and the following disclaimer.
10*1bbc47cbSCraig Rodrigues  * 2. Redistributions in binary form must reproduce the above copyright
11*1bbc47cbSCraig Rodrigues  *    notice, this list of conditions and the following disclaimer in the
12*1bbc47cbSCraig Rodrigues  *    documentation and/or other materials provided with the distribution.
13*1bbc47cbSCraig Rodrigues  *
14*1bbc47cbSCraig Rodrigues  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15*1bbc47cbSCraig Rodrigues  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16*1bbc47cbSCraig Rodrigues  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17*1bbc47cbSCraig Rodrigues  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18*1bbc47cbSCraig Rodrigues  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19*1bbc47cbSCraig Rodrigues  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20*1bbc47cbSCraig Rodrigues  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21*1bbc47cbSCraig Rodrigues  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22*1bbc47cbSCraig Rodrigues  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23*1bbc47cbSCraig Rodrigues  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24*1bbc47cbSCraig Rodrigues  * SUCH DAMAGE.
25*1bbc47cbSCraig Rodrigues  */
26*1bbc47cbSCraig Rodrigues 
27*1bbc47cbSCraig Rodrigues #include <sys/types.h>
28*1bbc47cbSCraig Rodrigues #include <sys/sysctl.h>
29*1bbc47cbSCraig Rodrigues #include <stddef.h>
30*1bbc47cbSCraig Rodrigues 
31*1bbc47cbSCraig Rodrigues int getdtablecount(void);
32*1bbc47cbSCraig Rodrigues 
33*1bbc47cbSCraig Rodrigues /*
34*1bbc47cbSCraig Rodrigues  * Return the count of open file descriptors for this process.
35*1bbc47cbSCraig Rodrigues  *
36*1bbc47cbSCraig Rodrigues  */
37*1bbc47cbSCraig Rodrigues int
getdtablecount(void)38*1bbc47cbSCraig Rodrigues getdtablecount(void)
39*1bbc47cbSCraig Rodrigues {
40*1bbc47cbSCraig Rodrigues 	int mib[4];
41*1bbc47cbSCraig Rodrigues 	int error;
42*1bbc47cbSCraig Rodrigues 	int nfds;
43*1bbc47cbSCraig Rodrigues 	size_t len;
44*1bbc47cbSCraig Rodrigues 
45*1bbc47cbSCraig Rodrigues 	len = sizeof(nfds);
46*1bbc47cbSCraig Rodrigues 	mib[0] = CTL_KERN;
47*1bbc47cbSCraig Rodrigues 	mib[1] = KERN_PROC;
48*1bbc47cbSCraig Rodrigues 	mib[2] = KERN_PROC_NFDS;
49*1bbc47cbSCraig Rodrigues 	mib[3] = 0;
50*1bbc47cbSCraig Rodrigues 
51*1bbc47cbSCraig Rodrigues 	error = sysctl(mib, 4, &nfds, &len, NULL, 0);
52*1bbc47cbSCraig Rodrigues 	if (error)
53*1bbc47cbSCraig Rodrigues 		return (-1);
54*1bbc47cbSCraig Rodrigues 	return (nfds);
55*1bbc47cbSCraig Rodrigues }
56