xref: /dragonfly/lib/libc/string/strerror.c (revision ed36d35d)
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: head/lib/libc/string/strerror.c 255108 2013-08-31 22:32:42Z jilles $
31  * (errlst.h removed)
32  */
33 
34 #if defined(NLS)
35 #include <nl_types.h>
36 #endif
37 
38 #include <limits.h>
39 #include <errno.h>
40 #include <string.h>
41 #include <stdio.h>
42 
43 #define	UPREFIX		"Unknown error"
44 
45 /*
46  * Define a buffer size big enough to describe a 64-bit signed integer
47  * converted to ASCII decimal (19 bytes), with an optional leading sign
48  * (1 byte); finally, we get the prefix, delimiter (": ") and a trailing
49  * NUL from UPREFIX.
50  */
51 #define	EBUFSIZE	(20 + 2 + sizeof(UPREFIX))
52 
53 /*
54  * Doing this by hand instead of linking with stdio(3) avoids bloat for
55  * statically linked binaries.
56  */
57 static void
58 errstr(int num, char *uprefix, char *buf, size_t len)
59 {
60 	char *t;
61 	unsigned int uerr;
62 	char tmp[EBUFSIZE];
63 
64 	t = tmp + sizeof(tmp);
65 	*--t = '\0';
66 	uerr = (num >= 0) ? num : -num;
67 	do {
68 		*--t = "0123456789"[uerr % 10];
69 	} while (uerr /= 10);
70 	if (num < 0)
71 		*--t = '-';
72 	*--t = ' ';
73 	*--t = ':';
74 	strlcpy(buf, uprefix, len);
75 	strlcat(buf, t, len);
76 }
77 
78 int
79 strerror_r(int errnum, char *strerrbuf, size_t buflen)
80 {
81 	int retval = 0;
82 #if defined(NLS)
83 	int saved_errno = errno;
84 	nl_catd catd;
85 	catd = catopen("libc", NL_CAT_LOCALE);
86 #endif
87 
88 	if (errnum < 0 || errnum >= sys_nerr) {
89 		errstr(errnum,
90 #if defined(NLS)
91 			catgets(catd, 1, 0xffff, UPREFIX),
92 #else
93 			UPREFIX,
94 #endif
95 			strerrbuf, buflen);
96 		retval = EINVAL;
97 	} else {
98 		if (strlcpy(strerrbuf,
99 #if defined(NLS)
100 			catgets(catd, 1, errnum, sys_errlist[errnum]),
101 #else
102 			sys_errlist[errnum],
103 #endif
104 			buflen) >= buflen)
105 		retval = ERANGE;
106 	}
107 
108 #if defined(NLS)
109 	catclose(catd);
110 	errno = saved_errno;
111 #endif
112 
113 	return (retval);
114 }
115 
116 char *
117 strerror(int num)
118 {
119 	static char ebuf[NL_TEXTMAX];
120 
121 	if (strerror_r(num, ebuf, sizeof(ebuf)) != 0)
122 		errno = EINVAL;
123 	return (ebuf);
124 }
125