xref: /dragonfly/lib/libc/string/strerror.c (revision dc71b7ab)
1 /*-
2  * Copyright (c) 1988, 1993
3  *	The Regents of the University of California.  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. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * @(#)strerror.c	8.1 (Berkeley) 6/4/93
30  * $FreeBSD: src/lib/libc/string/strerror.c,v 1.16 2007/01/09 00:28:12 imp Exp $
31  */
32 
33 #if defined(NLS)
34 #include <nl_types.h>
35 #endif
36 
37 #include <limits.h>
38 #include <errno.h>
39 #include <string.h>
40 #include <stdio.h>
41 
42 #define	UPREFIX		"Unknown error"
43 
44 /*
45  * Define a buffer size big enough to describe a 64-bit signed integer
46  * converted to ASCII decimal (19 bytes), with an optional leading sign
47  * (1 byte); finally, we get the prefix, delimiter (": ") and a trailing
48  * NUL from UPREFIX.
49  */
50 #define	EBUFSIZE	(20 + 2 + sizeof(UPREFIX))
51 
52 /*
53  * Doing this by hand instead of linking with stdio(3) avoids bloat for
54  * statically linked binaries.
55  */
56 static void
57 errstr(int num, char *uprefix, char *buf, size_t len)
58 {
59 	char *t;
60 	unsigned int uerr;
61 	char tmp[EBUFSIZE];
62 
63 	t = tmp + sizeof(tmp);
64 	*--t = '\0';
65 	uerr = (num >= 0) ? num : -num;
66 	do {
67 		*--t = "0123456789"[uerr % 10];
68 	} while (uerr /= 10);
69 	if (num < 0)
70 		*--t = '-';
71 	*--t = ' ';
72 	*--t = ':';
73 	strlcpy(buf, uprefix, len);
74 	strlcat(buf, t, len);
75 }
76 
77 int
78 strerror_r(int errnum, char *strerrbuf, size_t buflen)
79 {
80 	int retval = 0;
81 #if defined(NLS)
82 	int saved_errno = errno;
83 	nl_catd catd;
84 	catd = catopen("libc", NL_CAT_LOCALE);
85 #endif
86 
87 	if (errnum < 1 || errnum >= sys_nerr) {
88 		errstr(errnum,
89 #if defined(NLS)
90 			catgets(catd, 1, 0xffff, UPREFIX),
91 #else
92 			UPREFIX,
93 #endif
94 			strerrbuf, buflen);
95 		retval = EINVAL;
96 	} else {
97 		if (strlcpy(strerrbuf,
98 #if defined(NLS)
99 			catgets(catd, 1, errnum, sys_errlist[errnum]),
100 #else
101 			sys_errlist[errnum],
102 #endif
103 			buflen) >= buflen)
104 		retval = ERANGE;
105 	}
106 
107 #if defined(NLS)
108 	catclose(catd);
109 	errno = saved_errno;
110 #endif
111 
112 	return (retval);
113 }
114 
115 char *
116 strerror(int num)
117 {
118 	static char ebuf[NL_TEXTMAX];
119 
120 	if (strerror_r(num, ebuf, sizeof(ebuf)) != 0)
121 		errno = EINVAL;
122 	return (ebuf);
123 }
124