xref: /netbsd-src/lib/libc/stdio/perror.c (revision d9158b13b5dfe46201430699a3f7a235ecf28df3)
1 /*
2  * Copyright (c) 1988 Regents of the University of California.
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 the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #if defined(LIBC_SCCS) && !defined(lint)
35 /*static char *sccsid = "from: @(#)perror.c	5.11 (Berkeley) 2/24/91";*/
36 static char *rcsid = "$Id: perror.c,v 1.5 1993/10/09 00:11:19 jtc Exp $";
37 #endif /* LIBC_SCCS and not lint */
38 
39 #include <sys/types.h>
40 #include <sys/uio.h>
41 #include <unistd.h>
42 #include <errno.h>
43 #include <stdio.h>
44 #include <string.h>
45 
46 /*
47  * Since perror() is not allowed to change the contents of strerror()'s
48  * static buffer, both functions supply their own buffers to the
49  * internal function __strerror().
50  */
51 
52 extern char *__strerror __P((int , char *));
53 
54 void
55 perror(s)
56 	const char *s;
57 {
58 	register struct iovec *v;
59 	struct iovec iov[4];
60 	static char buf[40];
61 
62 	v = iov;
63 	if (s && *s) {
64 		v->iov_base = (char *)s;
65 		v->iov_len = strlen(s);
66 		v++;
67 		v->iov_base = ": ";
68 		v->iov_len = 2;
69 		v++;
70 	}
71 	v->iov_base = __strerror(errno, buf);
72 	v->iov_len = strlen(v->iov_base);
73 	v++;
74 	v->iov_base = "\n";
75 	v->iov_len = 1;
76 	(void)writev(STDERR_FILENO, iov, (v - iov) + 1);
77 }
78