xref: /netbsd-src/external/bsd/file/dist/src/dprintf.c (revision e15daa8be9575f7ad2ca804c7c7c2d7f8e182d98)
1 /*	$NetBSD: dprintf.c,v 1.1.1.3 2023/08/18 18:36:49 christos Exp $	*/
2 
3 /*
4  * Copyright (c) Ian F. Darwin 1986-1995.
5  * Software written by Ian F. Darwin and others;
6  * maintained 1995-present by Christos Zoulas and others.
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 immediately at the beginning of the file, without modification,
13  *    this list of conditions, and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
22  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 #include "file.h"
31 
32 #ifndef	lint
33 #if 0
34 FILE_RCSID("@(#)$File: dprintf.c,v 1.4 2022/09/24 20:30:13 christos Exp $")
35 #else
36 __RCSID("$NetBSD: dprintf.c,v 1.1.1.3 2023/08/18 18:36:49 christos Exp $");
37 #endif
38 #endif	/* lint */
39 
40 #include <assert.h>
41 #include <unistd.h>
42 #include <stdio.h>
43 #include <stdarg.h>
44 
45 int
dprintf(int fd,const char * fmt,...)46 dprintf(int fd, const char *fmt, ...)
47 {
48 	va_list ap;
49 	/* Simpler than using vasprintf() here, since we never need more */
50 	char buf[1024];
51 	int len;
52 
53 	va_start(ap, fmt);
54 	len = vsnprintf(buf, sizeof(buf), fmt, ap);
55 	va_end(ap);
56 
57 	if ((size_t)len >= sizeof(buf))
58 		return -1;
59 
60 	if (write(fd, buf, (size_t)len) != len)
61 		return -1;
62 
63 	return len;
64 }
65