xref: /freebsd/lib/libc/string/strerror.c (revision 8fc257994d0ce2396196d7a06d50d20c8015f4b7)
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  * 4. 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 
30 #if defined(LIBC_SCCS) && !defined(lint)
31 static char sccsid[] = "@(#)strerror.c	8.1 (Berkeley) 6/4/93";
32 #endif /* LIBC_SCCS and not lint */
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #if defined(NLS)
37 #include <nl_types.h>
38 #endif
39 
40 #include <limits.h>
41 #include <errno.h>
42 #include <string.h>
43 #include <stdio.h>
44 
45 #define	UPREFIX		"Unknown error"
46 
47 /*
48  * Define a buffer size big enough to describe a 64-bit signed integer
49  * converted to ASCII decimal (19 bytes), with an optional leading sign
50  * (1 byte); finally, we get the prefix, delimiter (": ") and a trailing
51  * NUL from UPREFIX.
52  */
53 #define	EBUFSIZE	(20 + 2 + sizeof(UPREFIX))
54 
55 /*
56  * Doing this by hand instead of linking with stdio(3) avoids bloat for
57  * statically linked binaries.
58  */
59 static void
60 errstr(int num, char *uprefix, char *buf, size_t len)
61 {
62 	char *t;
63 	unsigned int uerr;
64 	char tmp[EBUFSIZE];
65 
66 	t = tmp + sizeof(tmp);
67 	*--t = '\0';
68 	uerr = (num >= 0) ? num : -num;
69 	do {
70 		*--t = "0123456789"[uerr % 10];
71 	} while (uerr /= 10);
72 	if (num < 0)
73 		*--t = '-';
74 	*--t = ' ';
75 	*--t = ':';
76 	strlcpy(buf, uprefix, len);
77 	strlcat(buf, t, len);
78 }
79 
80 int
81 strerror_r(int errnum, char *strerrbuf, size_t buflen)
82 {
83 	int retval = 0;
84 #if defined(NLS)
85 	int saved_errno = errno;
86 	nl_catd catd;
87 	catd = catopen("libc", NL_CAT_LOCALE);
88 #endif
89 
90 	if (errnum < 1 || errnum >= sys_nerr) {
91 		errstr(errnum,
92 #if defined(NLS)
93 			catgets(catd, 1, 0xffff, UPREFIX),
94 #else
95 			UPREFIX,
96 #endif
97 			strerrbuf, buflen);
98 		retval = EINVAL;
99 	} else {
100 		if (strlcpy(strerrbuf,
101 #if defined(NLS)
102 			catgets(catd, 1, errnum, sys_errlist[errnum]),
103 #else
104 			sys_errlist[errnum],
105 #endif
106 			buflen) >= buflen)
107 		retval = ERANGE;
108 	}
109 
110 #if defined(NLS)
111 	catclose(catd);
112 	errno = saved_errno;
113 #endif
114 
115 	return (retval);
116 }
117 
118 char *
119 strerror(int num)
120 {
121 	static char ebuf[NL_TEXTMAX];
122 
123 	if (strerror_r(num, ebuf, sizeof(ebuf)) != 0)
124 	errno = EINVAL;
125 	return (ebuf);
126 }
127