1 /* $NetBSD: regsub.c,v 1.11 2023/02/20 02:11:07 mrg Exp $ */
2
3 /*-
4 * Copyright (c) 2015 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Christos Zoulas.
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 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 extern "C" {
33
34 #include <sys/param.h>
35 #include <ctype.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <regex.h>
39
40 struct str {
41 char *s_ptr;
42 size_t s_max;
43 size_t s_len;
44 int s_fixed;
45 };
46
47 #define REINCR 64
48
49 static int
addspace(struct str * s,size_t len)50 addspace(struct str *s, size_t len)
51 {
52 void *v;
53
54 if (s->s_max - s->s_len > len)
55 return 0;
56
57 if (s->s_fixed)
58 return -1;
59
60 s->s_max += len + REINCR;
61
62 v = realloc(s->s_ptr, s->s_max);
63 if (v == NULL)
64 return -1;
65 s->s_ptr = (char *)v;
66
67 return 0;
68 }
69
70 static void
addchar(struct str * s,int c)71 addchar(struct str *s, int c)
72 {
73 if (addspace(s, 1) == -1)
74 s->s_len++;
75 else
76 s->s_ptr[s->s_len++] = c;
77 if (c == 0) {
78 --s->s_len;
79 s->s_ptr[s->s_max - 1] = c;
80 }
81 }
82
83 static void
addnstr(struct str * s,const char * buf,size_t len)84 addnstr(struct str *s, const char *buf, size_t len)
85 {
86 if (addspace(s, len) != -1)
87 memcpy(s->s_ptr + s->s_len, buf, len);
88 s->s_len += len;
89 }
90
91 static int
initstr(struct str * s,char * buf,size_t len)92 initstr(struct str *s, char *buf, size_t len)
93 {
94 s->s_max = len;
95 s->s_ptr = (char *)(buf == NULL ? malloc(len) : buf);
96 s->s_fixed = buf != NULL;
97 s->s_len = 0;
98 return s->s_ptr == NULL ? -1 : 0;
99 }
100
101 static ssize_t
regsub1(char ** buf,size_t len,const char * sub,const regmatch_t * rm,const char * str)102 regsub1(char **buf, size_t len, const char *sub,
103 const regmatch_t *rm, const char *str)
104 {
105 ssize_t i;
106 char c;
107 struct str s;
108
109 if (initstr(&s, *buf, len) == -1)
110 return -1;
111
112 while ((c = *sub++) != '\0') {
113
114 switch (c) {
115 case '&':
116 i = 0;
117 break;
118 case '\\':
119 if (isdigit((unsigned char)*sub))
120 i = *sub++ - '0';
121 else
122 i = -1;
123 break;
124 default:
125 i = -1;
126 break;
127 }
128
129 if (i == -1) {
130 if (c == '\\' && (*sub == '\\' || *sub == '&'))
131 c = *sub++;
132 addchar(&s, c);
133 } else if (rm[i].rm_so != -1 && rm[i].rm_eo != -1) {
134 size_t l = (size_t)(rm[i].rm_eo - rm[i].rm_so);
135 addnstr(&s, str + rm[i].rm_so, l);
136 }
137 }
138
139 addchar(&s, '\0');
140 if (!s.s_fixed) {
141 if (s.s_len >= s.s_max) {
142 free(s.s_ptr);
143 return -1;
144 }
145 *buf = s.s_ptr;
146 }
147 return s.s_len;
148 }
149
150 ssize_t
regnsub(char * buf,size_t len,const char * sub,const regmatch_t * rm,const char * str)151 regnsub(char *buf, size_t len, const char *sub, const regmatch_t *rm,
152 const char *str)
153 {
154 return regsub1(&buf, len, sub, rm, str);
155 }
156
157 ssize_t
regasub(char ** buf,const char * sub,const regmatch_t * rm,const char * str)158 regasub(char **buf, const char *sub, const regmatch_t *rm, const char *str)
159 {
160 *buf = NULL;
161 return regsub1(buf, REINCR, sub, rm, str);
162 }
163
164 }
165