xref: /freebsd/bin/ed/sub.c (revision 2162b2d2265b5a190e84216b529977d83162f9cc)
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  *	$Id: sub.c,v 1.5 1995/03/19 13:28:38 joerg Exp $
29  */
30 
31 #ifndef lint
32 static char *rcsid = "@(#)sub.c,v 1.1 1994/02/01 00:34:44 alm Exp";
33 #endif /* not lint */
34 
35 #include "ed.h"
36 
37 
38 char *rhbuf;			/* rhs substitution buffer */
39 int rhbufsz;			/* rhs substitution buffer size */
40 int rhbufi;			/* rhs substitution buffer index */
41 
42 /* extract_subst_tail: extract substitution tail from the command buffer */
43 int
44 extract_subst_tail(flagp, np)
45 	int *flagp;
46 	int *np;
47 {
48 	char delimiter;
49 
50 	*flagp = *np = 0;
51 	if ((delimiter = *ibufp) == '\n') {
52 		rhbufi = 0;
53 		*flagp = GPR;
54 		return 0;
55 	} else if (extract_subst_template() == NULL)
56 		return  ERR;
57 	else if (*ibufp == '\n') {
58 		*flagp = GPR;
59 		return 0;
60 	} else if (*ibufp == delimiter)
61 		ibufp++;
62 	if ('1' <= *ibufp && *ibufp <= '9') {
63 		STRTOL(*np, ibufp);
64 		return 0;
65 	} else if (*ibufp == 'g') {
66 		ibufp++;
67 		*flagp = GSG;
68 		return 0;
69 	}
70 	return 0;
71 }
72 
73 
74 /* extract_subst_template: return pointer to copy of substitution template
75    in the command buffer */
76 char *
77 extract_subst_template()
78 {
79 	int n = 0;
80 	int i = 0;
81 	char c;
82 	char delimiter = *ibufp++;
83 
84 	if (*ibufp == '%' && *(ibufp + 1) == delimiter) {
85 		ibufp++;
86 		if (!rhbuf) sprintf(errmsg, "no previous substitution");
87 		return rhbuf;
88 	}
89 	while (*ibufp != delimiter) {
90 		REALLOC(rhbuf, rhbufsz, i + 2, NULL);
91 		if ((c = rhbuf[i++] = *ibufp++) == '\n' && *ibufp == '\0') {
92 			i--, ibufp--;
93 			break;
94 		} else if (c != '\\')
95 			;
96 		else if ((rhbuf[i++] = *ibufp++) != '\n')
97 			;
98 		else if (!isglobal) {
99 			while ((n = get_tty_line()) == 0 ||
100 			    (n > 0 && ibuf[n - 1] != '\n'))
101 				clearerr(stdin);
102 			if (n < 0)
103 				return NULL;
104 		}
105 	}
106 	REALLOC(rhbuf, rhbufsz, i + 1, NULL);
107 	rhbuf[rhbufi = i] = '\0';
108 	return  rhbuf;
109 }
110 
111 
112 char *rbuf;			/* substitute_matching_text buffer */
113 int rbufsz;			/* substitute_matching_text buffer size */
114 
115 /* search_and_replace: for each line in a range, change text matching a pattern
116    according to a substitution template; return status  */
117 int
118 search_and_replace(pat, gflag, kth)
119 	pattern_t *pat;
120 	int gflag;
121 	int kth;
122 {
123 	undo_t *up;
124 	char *txt;
125 	char *eot;
126 	long lc;
127 	long xa = current_addr;
128 	int nsubs = 0;
129 	line_t *lp;
130 	int len;
131 
132 	current_addr = first_addr - 1;
133 	for (lc = 0; lc <= second_addr - first_addr; lc++) {
134 		lp = get_addressed_line_node(++current_addr);
135 		if ((len = substitute_matching_text(pat, lp, gflag, kth)) < 0)
136 			return ERR;
137 		else if (len) {
138 			up = NULL;
139 			if (delete_lines(current_addr, current_addr) < 0)
140 				return ERR;
141 			txt = rbuf;
142 			eot = rbuf + len;
143 			SPL1();
144 			do {
145 				if ((txt = put_sbuf_line(txt)) == NULL) {
146 					SPL0();
147 					return ERR;
148 				} else if (up)
149 					up->t = get_addressed_line_node(current_addr);
150 				else if ((up = push_undo_stack(UADD,
151 				    current_addr, current_addr)) == NULL) {
152 					SPL0();
153 					return ERR;
154 				}
155 			} while (txt != eot);
156 			SPL0();
157 			nsubs++;
158 			xa = current_addr;
159 		}
160 	}
161 	current_addr = xa;
162 	if  (nsubs == 0 && !(gflag & GLB)) {
163 		sprintf(errmsg, "no match");
164 		return ERR;
165 	} else if ((gflag & (GPR | GLS | GNP)) &&
166 	    display_lines(current_addr, current_addr, gflag) < 0)
167 		return ERR;
168 	return 0;
169 }
170 
171 
172 /* substitute_matching_text: replace text matched by a pattern according to
173    a substitution template; return pointer to the modified text */
174 int
175 substitute_matching_text(pat, lp, gflag, kth)
176 	pattern_t *pat;
177 	line_t *lp;
178 	int gflag;
179 	int kth;
180 {
181 	int off = 0;
182 	int changed = 0;
183 	int matchno = 0;
184 	int i = 0;
185 	regmatch_t rm[SE_MAX];
186 	char *txt;
187 	char *eot;
188 
189 	if ((txt = get_sbuf_line(lp)) == NULL)
190 		return ERR;
191 	if (isbinary)
192 		NUL_TO_NEWLINE(txt, lp->len);
193 	eot = txt + lp->len;
194 	if (!regexec(pat, txt, SE_MAX, rm, 0)) {
195 		do {
196 			if (!kth || kth == ++matchno) {
197 				changed++;
198 				i = rm[0].rm_so;
199 				REALLOC(rbuf, rbufsz, off + i, ERR);
200 				if (isbinary)
201 					NEWLINE_TO_NUL(txt, rm[0].rm_eo);
202 				memcpy(rbuf + off, txt, i);
203 				off += i;
204 				if ((off = apply_subst_template(txt, rm, off,
205 				    pat->re_nsub)) < 0)
206 					return ERR;
207 			} else {
208 				i = rm[0].rm_eo;
209 				REALLOC(rbuf, rbufsz, off + i, ERR);
210 				if (isbinary)
211 					NEWLINE_TO_NUL(txt, i);
212 				memcpy(rbuf + off, txt, i);
213 				off += i;
214 			}
215 			txt += rm[0].rm_eo;
216 		} while (*txt &&
217                         (!changed || ((gflag & GSG) && rm[0].rm_eo)) &&
218 		        !regexec(pat, txt, SE_MAX, rm, REG_NOTBOL));
219 		i = eot - txt;
220 		REALLOC(rbuf, rbufsz, off + i + 2, ERR);
221 		if (i > 0 && !rm[0].rm_eo && (gflag & GSG)) {
222 			sprintf(errmsg, "infinite substitution loop");
223 			return  ERR;
224 		}
225 		if (isbinary)
226 			NEWLINE_TO_NUL(txt, i);
227 		memcpy(rbuf + off, txt, i);
228 		memcpy(rbuf + off + i, "\n", 2);
229 	}
230 	return changed ? off + i + 1 : 0;
231 }
232 
233 
234 /* apply_subst_template: modify text according to a substitution template;
235    return offset to end of modified text */
236 int
237 apply_subst_template(boln, rm, off, re_nsub)
238 	char *boln;
239 	regmatch_t *rm;
240 	int off;
241 	int re_nsub;
242 {
243 	int j = 0;
244 	int k = 0;
245 	int n;
246 	char *sub = rhbuf;
247 
248 	for (; sub - rhbuf < rhbufi; sub++)
249 		if (*sub == '&') {
250 			j = rm[0].rm_so;
251 			k = rm[0].rm_eo;
252 			REALLOC(rbuf, rbufsz, off + k - j, ERR);
253 			while (j < k)
254 				rbuf[off++] = boln[j++];
255 		} else if (*sub == '\\' && '1' <= *++sub && *sub <= '9' &&
256 		    (n = *sub - '0') <= re_nsub) {
257 			j = rm[n].rm_so;
258 			k = rm[n].rm_eo;
259 			REALLOC(rbuf, rbufsz, off + k - j, ERR);
260 			while (j < k)
261 				rbuf[off++] = boln[j++];
262 		} else {
263 			REALLOC(rbuf, rbufsz, off + 1, ERR);
264 			rbuf[off++] = *sub;
265 		}
266 	REALLOC(rbuf, rbufsz, off + 1, ERR);
267 	rbuf[off] = '\0';
268 	return off;
269 }
270