sub.c revision 1057
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#ifndef lint
30static char *rcsid = "@(#)$Id: sub.c,v 1.3 1993/12/15 15:22:02 alm Exp alm $";
31#endif /* not lint */
32
33#include "ed.h"
34
35
36char *rhbuf;			/* rhs substitution buffer */
37int rhbufsz;			/* rhs substitution buffer size */
38int rhbufi;			/* rhs substitution buffer index */
39
40/* extract_subst_tail: extract substitution tail from the command buffer */
41int
42extract_subst_tail(flagp, np)
43	int *flagp;
44	int *np;
45{
46	char delimiter;
47
48	*flagp = *np = 0;
49	if ((delimiter = *ibufp) == '\n') {
50		rhbufi = 0;
51		*flagp = GPR;
52		return 0;
53	} else if (extract_subst_template() == NULL)
54		return  ERR;
55	else if (*ibufp == '\n') {
56		*flagp = GPR;
57		return 0;
58	} else if (*ibufp == delimiter)
59		ibufp++;
60	if ('1' <= *ibufp && *ibufp <= '9') {
61		STRTOL(*np, ibufp);
62		return 0;
63	} else if (*ibufp == 'g') {
64		ibufp++;
65		*flagp = GSG;
66		return 0;
67	}
68	return 0;
69}
70
71
72/* extract_subst_template: return pointer to copy of substitution template
73   in the command buffer */
74char *
75extract_subst_template()
76{
77	int n = 0;
78	int i = 0;
79	char c;
80	char delimiter = *ibufp++;
81
82	if (*ibufp == '%' && *(ibufp + 1) == delimiter) {
83		ibufp++;
84		if (!rhbuf) sprintf(errmsg, "no previous substitution");
85		return rhbuf;
86	}
87	while (*ibufp != delimiter) {
88		REALLOC(rhbuf, rhbufsz, i + 2, NULL);
89		if ((c = rhbuf[i++] = *ibufp++) == '\n' && *ibufp == '\0') {
90			i--, ibufp--;
91			break;
92		} else if (c != '\\')
93			;
94		else if ((rhbuf[i++] = *ibufp++) != '\n')
95			;
96		else if (!isglobal) {
97			while ((n = get_tty_line()) == 0 ||
98			    n > 0 && ibuf[n - 1] != '\n')
99				clearerr(stdin);
100			if (n < 0)
101				return NULL;
102		}
103	}
104	REALLOC(rhbuf, rhbufsz, i + 1, NULL);
105	rhbuf[rhbufi = i] = '\0';
106	return  rhbuf;
107}
108
109
110char *rbuf;			/* substitute_matching_text buffer */
111int rbufsz;			/* substitute_matching_text buffer size */
112
113/* search_and_replace: for each line in a range, change text matching a pattern
114   according to a substitution template; return status  */
115int
116search_and_replace(pat, gflag, kth)
117	pattern_t *pat;
118	int gflag;
119	int kth;
120{
121	undo_t *up;
122	char *txt;
123	char *eot;
124	long lc;
125	int nsubs = 0;
126	line_t *lp;
127	int len;
128
129	current_addr = first_addr - 1;
130	for (lc = 0; lc <= second_addr - first_addr; lc++) {
131		lp = get_addressed_line_node(++current_addr);
132		if ((len = substitute_matching_text(pat, lp, gflag, kth)) < 0)
133			return ERR;
134		else if (len) {
135			up = NULL;
136			if (delete_lines(current_addr, current_addr) < 0)
137				return ERR;
138			txt = rbuf;
139			eot = rbuf + len;
140			SPL1();
141			do {
142				if ((txt = put_sbuf_line(txt)) == NULL) {
143					SPL0();
144					return ERR;
145				} else if (up)
146					up->t = get_addressed_line_node(current_addr);
147				else if ((up = push_undo_stack(UADD,
148				    current_addr, current_addr)) == NULL) {
149					SPL0();
150					return ERR;
151				}
152			} while (txt != eot);
153			SPL0();
154			nsubs++;
155		}
156	}
157	if  (nsubs == 0 && !(gflag & GLB)) {
158		sprintf(errmsg, "no match");
159		return ERR;
160	} else if ((gflag & (GPR | GLS | GNP)) &&
161	    display_lines(current_addr, current_addr, gflag) < 0)
162		return ERR;
163	return 0;
164}
165
166
167/* substitute_matching_text: replace text matched by a pattern according to
168   a substitution template; return pointer to the modified text */
169int
170substitute_matching_text(pat, lp, gflag, kth)
171	pattern_t *pat;
172	line_t *lp;
173	int gflag;
174	int kth;
175{
176	int off = 0;
177	int changed = 0;
178	int matchno = 0;
179	int i = 0;
180	regmatch_t rm[SE_MAX];
181	char *txt;
182	char *eot;
183
184	if ((txt = get_sbuf_line(lp)) == NULL)
185		return ERR;
186	if (isbinary)
187		NUL_TO_NEWLINE(txt, lp->len);
188	eot = txt + lp->len;
189	if (!regexec(pat, txt, SE_MAX, rm, 0)) {
190		do {
191			if (!kth || kth == ++matchno) {
192				changed++;
193				i = rm[0].rm_so;
194				REALLOC(rbuf, rbufsz, off + i, ERR);
195				if (isbinary)
196					NEWLINE_TO_NUL(txt, rm[0].rm_eo);
197				memcpy(rbuf + off, txt, i);
198				off += i;
199				if ((off = apply_subst_template(txt, rm, off,
200				    pat->re_nsub)) < 0)
201					return ERR;
202			} else {
203				i = rm[0].rm_eo;
204				REALLOC(rbuf, rbufsz, off + i, ERR);
205				if (isbinary)
206					NEWLINE_TO_NUL(txt, i);
207				memcpy(rbuf + off, txt, i);
208				off += i;
209			}
210			txt += rm[0].rm_eo;
211		} while (*txt && (!changed || (gflag & GSG) && rm[0].rm_eo) &&
212		    !regexec(pat, txt, SE_MAX, rm, REG_NOTBOL));
213		i = eot - txt;
214		REALLOC(rbuf, rbufsz, off + i + 2, ERR);
215		if (i > 0 && !rm[0].rm_eo && (gflag & GSG)) {
216			sprintf(errmsg, "infinite substitution loop");
217			return  ERR;
218		}
219		if (isbinary)
220			NEWLINE_TO_NUL(txt, i);
221		memcpy(rbuf + off, txt, i);
222		memcpy(rbuf + off + i, "\n", 2);
223	}
224	return changed ? off + i + 1 : 0;
225}
226
227
228/* apply_subst_template: modify text according to a substitution template;
229   return offset to end of modified text */
230int
231apply_subst_template(boln, rm, off, re_nsub)
232	char *boln;
233	regmatch_t *rm;
234	int off;
235	int re_nsub;
236{
237	int j = 0;
238	int k = 0;
239	int n;
240	char *sub = rhbuf;
241
242	for (; sub - rhbuf < rhbufi; sub++)
243		if (*sub == '&') {
244			j = rm[0].rm_so;
245			k = rm[0].rm_eo;
246			REALLOC(rbuf, rbufsz, off + k - j, ERR);
247			while (j < k)
248				rbuf[off++] = boln[j++];
249		} else if (*sub == '\\' && '1' <= *++sub && *sub <= '9' &&
250		    (n = *sub - '0') <= re_nsub) {
251			j = rm[n].rm_so;
252			k = rm[n].rm_eo;
253			REALLOC(rbuf, rbufsz, off + k - j, ERR);
254			while (j < k)
255				rbuf[off++] = boln[j++];
256		} else {
257			REALLOC(rbuf, rbufsz, off + 1, ERR);
258			rbuf[off++] = *sub;
259		}
260	REALLOC(rbuf, rbufsz, off + 1, ERR);
261	rbuf[off] = '\0';
262	return off;
263}
264