xref: /freebsd/contrib/nvi/vi/v_replace.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1 /*-
2  * Copyright (c) 1992, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  * Copyright (c) 1992, 1993, 1994, 1995, 1996
5  *	Keith Bostic.  All rights reserved.
6  *
7  * See the LICENSE file for redistribution information.
8  */
9 
10 #include "config.h"
11 
12 #include <sys/types.h>
13 #include <sys/queue.h>
14 #include <sys/time.h>
15 
16 #include <bitstring.h>
17 #include <ctype.h>
18 #include <errno.h>
19 #include <limits.h>
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <string.h>
23 
24 #include "../common/common.h"
25 #include "vi.h"
26 
27 /*
28  * v_replace -- [count]r<char>
29  *
30  * !!!
31  * The r command in historic vi was almost beautiful in its badness.  For
32  * example, "r<erase>" and "r<word erase>" beeped the terminal and deleted
33  * a single character.  "Nr<carriage return>", where N was greater than 1,
34  * inserted a single carriage return.  "r<escape>" did cancel the command,
35  * but "r<literal><escape>" erased a single character.  To enter a literal
36  * <literal> character, it required three <literal> characters after the
37  * command.  This may not be right, but at least it's not insane.
38  *
39  * PUBLIC: int v_replace(SCR *, VICMD *);
40  */
41 int
42 v_replace(SCR *sp, VICMD *vp)
43 {
44 	EVENT ev;
45 	VI_PRIVATE *vip;
46 	TEXT *tp;
47 	size_t blen, len;
48 	u_long cnt;
49 	int quote, rval;
50 	CHAR_T *bp;
51 	CHAR_T *p;
52 
53 	vip = VIP(sp);
54 
55 	/*
56 	 * If the line doesn't exist, or it's empty, replacement isn't
57 	 * allowed.  It's not hard to implement, but:
58 	 *
59 	 *	1: It's historic practice (vi beeped before the replacement
60 	 *	   character was even entered).
61 	 *	2: For consistency, this change would require that the more
62 	 *	   general case, "Nr", when the user is < N characters from
63 	 *	   the end of the line, also work, which would be a bit odd.
64 	 *	3: Replacing with a <newline> has somewhat odd semantics.
65 	 */
66 	if (db_get(sp, vp->m_start.lno, DBG_FATAL, &p, &len))
67 		return (1);
68 	if (len == 0) {
69 		msgq(sp, M_BERR, "186|No characters to replace");
70 		return (1);
71 	}
72 
73 	/*
74 	 * Figure out how many characters to be replace.  For no particular
75 	 * reason (other than that the semantics of replacing the newline
76 	 * are confusing) only permit the replacement of the characters in
77 	 * the current line.  I suppose we could append replacement characters
78 	 * to the line, but I see no compelling reason to do so.  Check this
79 	 * before we get the character to match historic practice, where Nr
80 	 * failed immediately if there were less than N characters from the
81 	 * cursor to the end of the line.
82 	 */
83 	cnt = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
84 	vp->m_stop.lno = vp->m_start.lno;
85 	vp->m_stop.cno = vp->m_start.cno + cnt - 1;
86 	if (vp->m_stop.cno > len - 1) {
87 		v_eol(sp, &vp->m_start);
88 		return (1);
89 	}
90 
91 	/*
92 	 * If it's not a repeat, reset the current mode and get a replacement
93 	 * character.
94 	 */
95 	quote = 0;
96 	if (!F_ISSET(vp, VC_ISDOT)) {
97 		sp->showmode = SM_REPLACE;
98 		if (vs_refresh(sp, 0))
99 			return (1);
100 next:		if (v_event_get(sp, &ev, 0, 0))
101 			return (1);
102 
103 		switch (ev.e_event) {
104 		case E_CHARACTER:
105 			/*
106 			 * <literal_next> means escape the next character.
107 			 * <escape> means they changed their minds.
108 			 */
109 			if (!quote) {
110 				if (ev.e_value == K_VLNEXT) {
111 					quote = 1;
112 					goto next;
113 				}
114 				if (ev.e_value == K_ESCAPE)
115 					return (0);
116 			}
117 			vip->rlast = ev.e_c;
118 			vip->rvalue = ev.e_value;
119 			break;
120 		case E_ERR:
121 		case E_EOF:
122 			F_SET(sp, SC_EXIT_FORCE);
123 			return (1);
124 		case E_INTERRUPT:
125 			/* <interrupt> means they changed their minds. */
126 			return (0);
127 		case E_WRESIZE:
128 			/* <resize> interrupts the input mode. */
129 			v_emsg(sp, NULL, VIM_WRESIZE);
130 			return (0);
131 		case E_REPAINT:
132 			if (vs_repaint(sp, &ev))
133 				return (1);
134 			goto next;
135 		default:
136 			v_event_err(sp, &ev);
137 			return (0);
138 		}
139 	}
140 
141 	/* Copy the line. */
142 	GET_SPACE_RETW(sp, bp, blen, len);
143 	MEMMOVE(bp, p, len);
144 	p = bp;
145 
146 	/*
147 	 * Versions of nvi before 1.57 created N new lines when they replaced
148 	 * N characters with <carriage-return> or <newline> characters.  This
149 	 * is different from the historic vi, which replaced N characters with
150 	 * a single new line.  Users complained, so we match historic practice.
151 	 */
152 	if ((!quote && vip->rvalue == K_CR) || vip->rvalue == K_NL) {
153 		/* Set return line. */
154 		vp->m_stop.lno = vp->m_start.lno + 1;
155 		vp->m_stop.cno = 0;
156 
157 		/* The first part of the current line. */
158 		if (db_set(sp, vp->m_start.lno, p, vp->m_start.cno))
159 			goto err_ret;
160 
161 		/*
162 		 * The rest of the current line.  And, of course, now it gets
163 		 * tricky.  If there are characters left in the line and if
164 		 * the autoindent edit option is set, white space after the
165 		 * replaced character is discarded, autoindent is applied, and
166 		 * the cursor moves to the last indent character.
167 		 */
168 		p += vp->m_start.cno + cnt;
169 		len -= vp->m_start.cno + cnt;
170 		if (len != 0 && O_ISSET(sp, O_AUTOINDENT))
171 			for (; len && isblank(*p); --len, ++p);
172 
173 		if ((tp = text_init(sp, p, len, len)) == NULL)
174 			goto err_ret;
175 
176 		if (len != 0 && O_ISSET(sp, O_AUTOINDENT)) {
177 			if (v_txt_auto(sp, vp->m_start.lno, NULL, 0, tp))
178 				goto err_ret;
179 			vp->m_stop.cno = tp->ai ? tp->ai - 1 : 0;
180 		} else
181 			vp->m_stop.cno = 0;
182 
183 		vp->m_stop.cno = tp->ai ? tp->ai - 1 : 0;
184 		if (db_append(sp, 1, vp->m_start.lno, tp->lb, tp->len))
185 err_ret:		rval = 1;
186 		else {
187 			text_free(tp);
188 			rval = 0;
189 		}
190 	} else {
191 		STRSET(bp + vp->m_start.cno, vip->rlast, cnt);
192 		rval = db_set(sp, vp->m_start.lno, bp, len);
193 	}
194 	FREE_SPACEW(sp, bp, blen);
195 
196 	vp->m_final = vp->m_stop;
197 	return (rval);
198 }
199