xref: /openbsd/lib/libc/regex/regerror.c (revision 7b36286a)
1 /*	$OpenBSD: regerror.c,v 1.13 2005/08/05 13:03:00 espie Exp $ */
2 /*-
3  * Copyright (c) 1992, 1993, 1994 Henry Spencer.
4  * Copyright (c) 1992, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Henry Spencer.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	@(#)regerror.c	8.4 (Berkeley) 3/20/94
35  */
36 
37 #include <sys/types.h>
38 #include <stdio.h>
39 #include <string.h>
40 #include <ctype.h>
41 #include <limits.h>
42 #include <stdlib.h>
43 #include <regex.h>
44 
45 #include "utils.h"
46 
47 static char *regatoi(const regex_t *, char *, int);
48 
49 static struct rerr {
50 	int code;
51 	char *name;
52 	char *explain;
53 } rerrs[] = {
54 	{ REG_NOMATCH,	"REG_NOMATCH",	"regexec() failed to match" },
55 	{ REG_BADPAT,	"REG_BADPAT",	"invalid regular expression" },
56 	{ REG_ECOLLATE,	"REG_ECOLLATE",	"invalid collating element" },
57 	{ REG_ECTYPE,	"REG_ECTYPE",	"invalid character class" },
58 	{ REG_EESCAPE,	"REG_EESCAPE",	"trailing backslash (\\)" },
59 	{ REG_ESUBREG,	"REG_ESUBREG",	"invalid backreference number" },
60 	{ REG_EBRACK,	"REG_EBRACK",	"brackets ([ ]) not balanced" },
61 	{ REG_EPAREN,	"REG_EPAREN",	"parentheses not balanced" },
62 	{ REG_EBRACE,	"REG_EBRACE",	"braces not balanced" },
63 	{ REG_BADBR,	"REG_BADBR",	"invalid repetition count(s)" },
64 	{ REG_ERANGE,	"REG_ERANGE",	"invalid character range" },
65 	{ REG_ESPACE,	"REG_ESPACE",	"out of memory" },
66 	{ REG_BADRPT,	"REG_BADRPT",	"repetition-operator operand invalid" },
67 	{ REG_EMPTY,	"REG_EMPTY",	"empty (sub)expression" },
68 	{ REG_ASSERT,	"REG_ASSERT",	"\"can't happen\" -- you found a bug" },
69 	{ REG_INVARG,	"REG_INVARG",	"invalid argument to regex routine" },
70 	{ 0,		"",		"*** unknown regexp error code ***" }
71 };
72 
73 /*
74  - regerror - the interface to error numbers
75  = extern size_t regerror(int, const regex_t *, char *, size_t);
76  */
77 /* ARGSUSED */
78 size_t
79 regerror(int errcode, const regex_t *preg, char *errbuf, size_t errbuf_size)
80 {
81 	struct rerr *r;
82 	size_t len;
83 	int target = errcode &~ REG_ITOA;
84 	char *s;
85 	char convbuf[50];
86 
87 	if (errcode == REG_ATOI)
88 		s = regatoi(preg, convbuf, sizeof convbuf);
89 	else {
90 		for (r = rerrs; r->code != 0; r++)
91 			if (r->code == target)
92 				break;
93 
94 		if (errcode&REG_ITOA) {
95 			if (r->code != 0) {
96 				assert(strlen(r->name) < sizeof(convbuf));
97 				(void) strlcpy(convbuf, r->name, sizeof convbuf);
98 			} else
99 				(void)snprintf(convbuf, sizeof convbuf,
100 				    "REG_0x%x", target);
101 			s = convbuf;
102 		} else
103 			s = r->explain;
104 	}
105 
106 	len = strlen(s) + 1;
107 	if (errbuf_size > 0) {
108 		strlcpy(errbuf, s, errbuf_size);
109 	}
110 
111 	return(len);
112 }
113 
114 /*
115  - regatoi - internal routine to implement REG_ATOI
116  */
117 static char *
118 regatoi(const regex_t *preg, char *localbuf, int localbufsize)
119 {
120 	struct rerr *r;
121 
122 	for (r = rerrs; r->code != 0; r++)
123 		if (strcmp(r->name, preg->re_endp) == 0)
124 			break;
125 	if (r->code == 0)
126 		return("0");
127 
128 	(void)snprintf(localbuf, localbufsize, "%d", r->code);
129 	return(localbuf);
130 }
131