xref: /illumos-gate/usr/src/lib/libresolv2/common/bsd/strerror.c (revision 55fea89dcaa64928bed4327112404dcb3e07b79f)
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. 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 #include "port_before.h"
35 
36 #include <sys/param.h>
37 #include <sys/types.h>
38 
39 #include <string.h>
40 
41 #include "port_after.h"
42 
43 #ifndef NEED_STRERROR
44 int __strerror_unneeded__;
45 #else
46 
47 #ifdef USE_SYSERROR_LIST
48 extern int sys_nerr;
49 extern char *sys_errlist[];
50 #endif
51 
52 const char *
isc_strerror(int num)53 isc_strerror(int num) {
54 #define	UPREFIX	"Unknown error: "
55 	static char ebuf[40] = UPREFIX;		/*%< 64-bit number + slop */
56 	u_int errnum;
57 	char *p, *t;
58 #ifndef USE_SYSERROR_LIST
59 	const char *ret;
60 #endif
61 	char tmp[40];
62 
63 	errnum = num;				/*%< convert to unsigned */
64 #ifdef USE_SYSERROR_LIST
65 	if (errnum < (u_int)sys_nerr)
66 		return (sys_errlist[errnum]);
67 #else
68 #undef strerror
69 	ret = strerror(num);			/*%< call strerror() in libc */
70 	if (ret != NULL)
71 		return(ret);
72 #endif
73 
74 	/* Do this by hand, so we don't include stdio(3). */
75 	t = tmp;
76 	do {
77 		*t++ = "0123456789"[errnum % 10];
78 	} while (errnum /= 10);
79 	for (p = ebuf + sizeof(UPREFIX) - 1;;) {
80 		*p++ = *--t;
81 		if (t <= tmp)
82 			break;
83 	}
84 	return (ebuf);
85 }
86 
87 #endif /*NEED_STRERROR*/
88 
89 /*! \file */
90