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