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
47static const char *regatoi(const regex_t *, char *, int);
48
49static const struct rerr {
50	int code;
51	const char *name;
52	const 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 */
78size_t
79regerror(int errcode, const regex_t *preg, char *errbuf, size_t errbuf_size)
80{
81	const struct rerr *r;
82	size_t len;
83	int target = errcode &~ REG_ITOA;
84	const 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) strncpy(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		strncpy(errbuf, s, errbuf_size);
109	}
110
111	return(len);
112}
113
114/*
115 - regatoi - internal routine to implement REG_ATOI
116 */
117static const char *
118regatoi(const regex_t *preg, char *localbuf, int localbufsize)
119{
120	const 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