1/*	$OpenBSD: setproctitle.c,v 1.16 2020/10/12 22:08:33 deraadt Exp $ */
2/*
3 * Copyright (c) 1994, 1995 Christopher G. Demetriou
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 *    must display the following acknowledgement:
16 *      This product includes software developed by Christopher G. Demetriou
17 *	for the NetBSD Project.
18 * 4. The name of the author may not be used to endorse or promote products
19 *    derived from this software without specific prior written permission
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 */
32
33#include <sys/types.h>
34#include <sys/exec.h>
35#include <sys/sysctl.h>
36
37#include <stdio.h>
38#include <stdlib.h>
39#include <string.h>
40#include <stdarg.h>
41
42#define	MAX_PROCTITLE	2048
43
44void
45setproctitle(const char *fmt, ...)
46{
47	static struct ps_strings *ps;
48	va_list ap;
49
50	static char buf[MAX_PROCTITLE], *bufp = buf;
51	int used;
52
53	va_start(ap, fmt);
54	if (fmt != NULL) {
55		used = snprintf(buf, MAX_PROCTITLE, "%s: ", __progname);
56		if (used >= MAX_PROCTITLE)
57			used = MAX_PROCTITLE - 1;
58		else if (used < 0)
59			used = 0;
60		(void)vsnprintf(buf + used, MAX_PROCTITLE - used, fmt, ap);
61	} else
62		(void)snprintf(buf, MAX_PROCTITLE, "%s", __progname);
63	va_end(ap);
64
65	if (ps == NULL) {
66		struct _ps_strings _ps;
67		const int mib[2] = { CTL_VM, VM_PSSTRINGS };
68		size_t len;
69
70		len = sizeof(_ps);
71		if (sysctl(mib, 2, &_ps, &len, NULL, 0) != 0)
72			return;
73		ps = (struct ps_strings *)_ps.val;
74	}
75	ps->ps_nargvstr = 1;
76	ps->ps_argvstr = &bufp;
77}
78