1 /* $OpenBSD: snprintf.c,v 1.7 2019/05/11 16:56:47 deraadt Exp $ */
2 /* $NetBSD: printf.c,v 1.10 1996/11/30 04:19:21 gwr Exp $ */
3
4 /*-
5 * Copyright (c) 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * @(#)printf.c 8.1 (Berkeley) 6/11/93
33 */
34
35 #include <sys/types.h>
36 #include <sys/stdarg.h>
37
38 #include "stand.h"
39
40 extern void kprintn(void (*)(int), u_long, int);
41 extern void kdoprnt(void (*)(int), const char *, va_list);
42
43 static void sputchar(int);
44
45 static char *sbuf, *sbuf_end;
46
47 void
sputchar(int c)48 sputchar(int c)
49 {
50 if (sbuf < sbuf_end)
51 *sbuf = c;
52 sbuf++;
53 }
54
55 int
snprintf(char * buf,size_t len,const char * fmt,...)56 snprintf(char *buf, size_t len, const char *fmt, ...)
57 {
58 va_list ap;
59
60 sbuf = buf;
61 sbuf_end = sbuf + len;
62 va_start(ap, fmt);
63 kdoprnt(sputchar, fmt, ap);
64 va_end(ap);
65
66 if (sbuf < sbuf_end)
67 *sbuf = '\0';
68 else if (len > 0)
69 *(sbuf_end - 1) = '\0';
70
71 return sbuf - buf;
72 }
73