1 /* sub.c: This file contains the substitution routines for the ed
2 line editor */
3 /*-
4 * Copyright (c) 1993 Andrew Moore, Talke Studio.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 #include "ed.h"
31
32
33 static char *rhbuf; /* rhs substitution buffer */
34 static int rhbufsz; /* rhs substitution buffer size */
35 static int rhbufi; /* rhs substitution buffer index */
36
37 /* extract_subst_tail: extract substitution tail from the command buffer */
38 int
extract_subst_tail(int * flagp,long * np)39 extract_subst_tail(int *flagp, long *np)
40 {
41 char delimiter;
42
43 *flagp = *np = 0;
44 if ((delimiter = *ibufp) == '\n') {
45 rhbufi = 0;
46 *flagp = GPR;
47 return 0;
48 } else if (extract_subst_template() == NULL)
49 return ERR;
50 else if (*ibufp == '\n') {
51 *flagp = GPR;
52 return 0;
53 } else if (*ibufp == delimiter)
54 ibufp++;
55 if ('1' <= *ibufp && *ibufp <= '9') {
56 STRTOL(*np, ibufp);
57 return 0;
58 } else if (*ibufp == 'g') {
59 ibufp++;
60 *flagp = GSG;
61 return 0;
62 }
63 return 0;
64 }
65
66
67 /* extract_subst_template: return pointer to copy of substitution template
68 in the command buffer */
69 char *
extract_subst_template(void)70 extract_subst_template(void)
71 {
72 int n = 0;
73 int i = 0;
74 char c;
75 char delimiter = *ibufp++;
76
77 if (*ibufp == '%' && *(ibufp + 1) == delimiter) {
78 ibufp++;
79 if (!rhbuf)
80 errmsg = "no previous substitution";
81 return rhbuf;
82 }
83 while (*ibufp != delimiter) {
84 REALLOC(rhbuf, rhbufsz, i + 2, NULL);
85 if ((c = rhbuf[i++] = *ibufp++) == '\n' && *ibufp == '\0') {
86 i--, ibufp--;
87 break;
88 } else if (c != '\\')
89 ;
90 else if ((rhbuf[i++] = *ibufp++) != '\n')
91 ;
92 else if (!isglobal) {
93 while ((n = get_tty_line()) == 0 ||
94 (n > 0 && ibuf[n - 1] != '\n'))
95 clearerr(stdin);
96 if (n < 0)
97 return NULL;
98 }
99 }
100 REALLOC(rhbuf, rhbufsz, i + 1, NULL);
101 rhbuf[rhbufi = i] = '\0';
102 return rhbuf;
103 }
104
105
106 static char *rbuf; /* substitute_matching_text buffer */
107 static int rbufsz; /* substitute_matching_text buffer size */
108
109 /* search_and_replace: for each line in a range, change text matching a pattern
110 according to a substitution template; return status */
111 int
search_and_replace(pattern_t * pat,int gflag,int kth)112 search_and_replace(pattern_t *pat, int gflag, int kth)
113 {
114 undo_t *up;
115 const char *txt;
116 const char *eot;
117 long lc;
118 long xa = current_addr;
119 int nsubs = 0;
120 line_t *lp;
121 int len;
122
123 current_addr = first_addr - 1;
124 for (lc = 0; lc <= second_addr - first_addr; lc++) {
125 lp = get_addressed_line_node(++current_addr);
126 if ((len = substitute_matching_text(pat, lp, gflag, kth)) < 0)
127 return ERR;
128 else if (len) {
129 up = NULL;
130 if (delete_lines(current_addr, current_addr) < 0)
131 return ERR;
132 txt = rbuf;
133 eot = rbuf + len;
134 SPL1();
135 do {
136 if ((txt = put_sbuf_line(txt)) == NULL) {
137 SPL0();
138 return ERR;
139 } else if (up)
140 up->t = get_addressed_line_node(current_addr);
141 else if ((up = push_undo_stack(UADD,
142 current_addr, current_addr)) == NULL) {
143 SPL0();
144 return ERR;
145 }
146 } while (txt != eot);
147 SPL0();
148 nsubs++;
149 xa = current_addr;
150 }
151 }
152 current_addr = xa;
153 if (nsubs == 0 && !(gflag & GLB)) {
154 errmsg = "no match";
155 return ERR;
156 } else if ((gflag & (GPR | GLS | GNP)) &&
157 display_lines(current_addr, current_addr, gflag) < 0)
158 return ERR;
159 return 0;
160 }
161
162
163 /* substitute_matching_text: replace text matched by a pattern according to
164 a substitution template; return pointer to the modified text */
165 int
substitute_matching_text(pattern_t * pat,line_t * lp,int gflag,int kth)166 substitute_matching_text(pattern_t *pat, line_t *lp, int gflag, int kth)
167 {
168 int off = 0;
169 int changed = 0;
170 int matchno = 0;
171 int i = 0;
172 regmatch_t rm[SE_MAX];
173 char *txt;
174 char *eot;
175
176 if ((txt = get_sbuf_line(lp)) == NULL)
177 return ERR;
178 if (isbinary)
179 NUL_TO_NEWLINE(txt, lp->len);
180 eot = txt + lp->len;
181 if (!regexec(pat, txt, SE_MAX, rm, 0)) {
182 do {
183 if (!kth || kth == ++matchno) {
184 changed++;
185 i = rm[0].rm_so;
186 REALLOC(rbuf, rbufsz, off + i, ERR);
187 if (isbinary)
188 NEWLINE_TO_NUL(txt, rm[0].rm_eo);
189 memcpy(rbuf + off, txt, i);
190 off += i;
191 if ((off = apply_subst_template(txt, rm, off,
192 pat->re_nsub)) < 0)
193 return ERR;
194 } else {
195 i = rm[0].rm_eo;
196 REALLOC(rbuf, rbufsz, off + i, ERR);
197 if (isbinary)
198 NEWLINE_TO_NUL(txt, i);
199 memcpy(rbuf + off, txt, i);
200 off += i;
201 }
202 txt += rm[0].rm_eo;
203 } while (*txt &&
204 (!changed || ((gflag & GSG) && rm[0].rm_eo)) &&
205 !regexec(pat, txt, SE_MAX, rm, REG_NOTBOL));
206 i = eot - txt;
207 REALLOC(rbuf, rbufsz, off + i + 2, ERR);
208 if (i > 0 && !rm[0].rm_eo && (gflag & GSG)) {
209 errmsg = "infinite substitution loop";
210 return ERR;
211 }
212 if (isbinary)
213 NEWLINE_TO_NUL(txt, i);
214 memcpy(rbuf + off, txt, i);
215 memcpy(rbuf + off + i, "\n", 2);
216 }
217 return changed ? off + i + 1 : 0;
218 }
219
220
221 /* apply_subst_template: modify text according to a substitution template;
222 return offset to end of modified text */
223 int
apply_subst_template(const char * boln,regmatch_t * rm,int off,int re_nsub)224 apply_subst_template(const char *boln, regmatch_t *rm, int off, int re_nsub)
225 {
226 int j = 0;
227 int k = 0;
228 int n;
229 char *sub = rhbuf;
230
231 for (; sub - rhbuf < rhbufi; sub++)
232 if (*sub == '&') {
233 j = rm[0].rm_so;
234 k = rm[0].rm_eo;
235 REALLOC(rbuf, rbufsz, off + k - j, ERR);
236 while (j < k)
237 rbuf[off++] = boln[j++];
238 } else if (*sub == '\\' && '1' <= *++sub && *sub <= '9' &&
239 (n = *sub - '0') <= re_nsub) {
240 j = rm[n].rm_so;
241 k = rm[n].rm_eo;
242 REALLOC(rbuf, rbufsz, off + k - j, ERR);
243 while (j < k)
244 rbuf[off++] = boln[j++];
245 } else {
246 REALLOC(rbuf, rbufsz, off + 1, ERR);
247 rbuf[off++] = *sub;
248 }
249 REALLOC(rbuf, rbufsz, off + 1, ERR);
250 rbuf[off] = '\0';
251 return off;
252 }
253