1 /* $NetBSD: regsub.c,v 1.4 2024/01/23 15:32:54 christos 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 #include <sys/cdefs.h>
32 #if defined(LIBC_SCCS) && !defined(lint)
33 __RCSID("$NetBSD: regsub.c,v 1.4 2024/01/23 15:32:54 christos Exp $");
34 #endif
35
36 #include <sys/param.h>
37 #include <ctype.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <regex.h>
41
42 struct str {
43 char *s_ptr;
44 size_t s_max;
45 size_t s_len;
46 int s_fixed;
47 };
48
49 #define REINCR 64
50
51 static int
addspace(struct str * s,size_t len)52 addspace(struct str *s, size_t len)
53 {
54 void *v;
55
56 if (s->s_max - s->s_len > len)
57 return 0;
58
59 if (s->s_fixed)
60 return -1;
61
62 s->s_max += len + REINCR;
63
64 v = realloc(s->s_ptr, s->s_max);
65 if (v == NULL)
66 return -1;
67 s->s_ptr = v;
68
69 return 0;
70 }
71
72 static void
addchar(struct str * s,int c)73 addchar(struct str *s, int c)
74 {
75 if (addspace(s, 1) == -1)
76 s->s_len++;
77 else
78 s->s_ptr[s->s_len++] = c;
79 if (c == 0) {
80 --s->s_len;
81 s->s_ptr[s->s_max - 1] = c;
82 }
83 }
84
85 static void
addnstr(struct str * s,const char * buf,size_t len)86 addnstr(struct str *s, const char *buf, size_t len)
87 {
88 if (addspace(s, len) != -1)
89 memcpy(s->s_ptr + s->s_len, buf, len);
90 s->s_len += len;
91 }
92
93 static int
initstr(struct str * s,char * buf,size_t len)94 initstr(struct str *s, char *buf, size_t len)
95 {
96 s->s_max = len;
97 s->s_ptr = buf == NULL ? malloc(len) : buf;
98 s->s_fixed = buf != NULL;
99 s->s_len = 0;
100 return s->s_ptr == NULL ? -1 : 0;
101 }
102
103 static ssize_t
regsub1(char ** buf,size_t len,const char * sub,const regmatch_t * rm,const char * str)104 regsub1(char **buf, size_t len, const char *sub,
105 const regmatch_t *rm, const char *str)
106 {
107 ssize_t i;
108 char c;
109 struct str s;
110
111 if (initstr(&s, *buf, len) == -1)
112 return -1;
113
114 while ((c = *sub++) != '\0') {
115
116 switch (c) {
117 case '&':
118 i = 0;
119 break;
120 case '\\':
121 if (isdigit((unsigned char)*sub))
122 i = *sub++ - '0';
123 else
124 i = -1;
125 break;
126 default:
127 i = -1;
128 break;
129 }
130
131 if (i == -1) {
132 if (c == '\\' && (*sub == '\\' || *sub == '&'))
133 c = *sub++;
134 addchar(&s, c);
135 } else if (rm[i].rm_so != -1 && rm[i].rm_eo != -1) {
136 size_t l = (size_t)(rm[i].rm_eo - rm[i].rm_so);
137 addnstr(&s, str + (size_t)rm[i].rm_so, l);
138 }
139 }
140
141 addchar(&s, '\0');
142 if (!s.s_fixed) {
143 if (s.s_len >= s.s_max) {
144 free(s.s_ptr);
145 return -1;
146 }
147 *buf = s.s_ptr;
148 }
149 return s.s_len;
150 }
151
152 ssize_t
regnsub(char * buf,size_t len,const char * sub,const regmatch_t * rm,const char * str)153 regnsub(char *buf, size_t len, const char *sub, const regmatch_t *rm,
154 const char *str)
155 {
156 return regsub1(&buf, len, sub, rm, str);
157 }
158
159 ssize_t
regasub(char ** buf,const char * sub,const regmatch_t * rm,const char * str)160 regasub(char **buf, const char *sub, const regmatch_t *rm, const char *str)
161 {
162 *buf = NULL;
163 return regsub1(buf, REINCR, sub, rm, str);
164 }
165