xref: /openbsd-src/lib/libc/gen/setproctitle.c (revision db3296cf5c1dd9058ceecc3a29fe4aaa0bd26000)
1 /*
2  * Copyright (c) 1994, 1995 Christopher G. Demetriou
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *      This product includes software developed by Christopher G. Demetriou
16  *	for the NetBSD Project.
17  * 4. The name of the author may not be used to endorse or promote products
18  *    derived from this software without specific prior written permission
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #if defined(LIBC_SCCS) && !defined(lint)
33 static char rcsid[] = "$OpenBSD: setproctitle.c,v 1.9 2002/02/19 19:39:36 millert Exp $";
34 #endif /* LIBC_SCCS and not lint */
35 
36 #include <sys/param.h>
37 #include <sys/types.h>
38 #include <sys/exec.h>
39 #include <sys/sysctl.h>
40 
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <stdarg.h>
45 
46 #define	MAX_PROCTITLE	2048
47 
48 extern char *__progname;		/* Program name, from crt0. */
49 
50 void
51 setproctitle(const char *fmt, ...)
52 {
53 	static struct ps_strings *ps;
54 	va_list ap;
55 
56 	static char buf[MAX_PROCTITLE], *bufp = buf;
57 	size_t used;
58 
59 	va_start(ap, fmt);
60 	if (fmt != NULL) {
61 		used = snprintf(buf, MAX_PROCTITLE, "%s: ", __progname);
62 		if (used >= MAX_PROCTITLE)
63 			used = MAX_PROCTITLE - 1;
64 		(void)vsnprintf(buf + used, MAX_PROCTITLE - used, fmt, ap);
65 	} else
66 		(void)snprintf(buf, MAX_PROCTITLE, "%s", __progname);
67 	va_end(ap);
68 
69 	if (ps == NULL) {
70 		struct _ps_strings _ps;
71 		int mib[2];
72 		size_t len;
73 
74 		mib[0] = CTL_VM;
75 		mib[1] = VM_PSSTRINGS;
76 		len = sizeof(_ps);
77 		if (sysctl(mib, 2, &_ps, &len, NULL, 0) != 0)
78 			return;
79 		ps = (struct ps_strings *)_ps.val;
80 	}
81 	ps->ps_nargvstr = 1;
82 	ps->ps_argvstr = &bufp;
83 }
84