1 /*	$NetBSD: eprintf.c,v 1.2 2009/03/14 15:36:04 dsl Exp $	*/
2 
3 /*
4  * Copyright (c) 1995 Waldi Ravens.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, 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  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *        This product includes software developed by Waldi Ravens.
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 <fcntl.h>
34 #include <errno.h>
35 #include <stdio.h>
36 #include <stdarg.h>
37 #include <unistd.h>
38 #include "libtos.h"
39 
40 static int	output_redirected = 0;
41 
42 void
43 redirect_output(char *fn)
44 {
45 	int	fd;
46 
47 	fd = creat(fn, 0666);
48 	if (fd < 0 || dup2(fd, STDOUT_FILENO) < 0)
49 		fatal(errno, "%s", fn);
50 	output_redirected = 1;
51 }
52 
53 /*
54  * Print output to stderr. When output is redirected,
55  * also write it to stdout.
56  */
57 int
58 eprintf(char *frm)
59 {
60 	va_list	args;
61 	int	rv;
62 
63 	va_start(args, frm);
64 	rv = veprintf(frm, args);
65 	va_end(args);
66 	return(rv);
67 }
68 
69 int
70 veprintf(char *frm, va_list args)
71 {
72 	int	rv;
73 
74 	rv = vfprintf(stderr, frm, args);
75 	if (output_redirected)
76 		vfprintf(stdout, frm, args);
77 	return(rv);
78 }
79