/bin/ed/sub.c

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