xref: /netbsd-src/external/bsd/nvi/dist/common/delete.c (revision a07ca21052e91224e1a8b79aa76256a519355213)
1 /*	$NetBSD: delete.c,v 1.4 2017/11/22 12:47:30 rin Exp $ */
2 /*-
3  * Copyright (c) 1992, 1993, 1994
4  *	The Regents of the University of California.  All rights reserved.
5  * Copyright (c) 1992, 1993, 1994, 1995, 1996
6  *	Keith Bostic.  All rights reserved.
7  *
8  * See the LICENSE file for redistribution information.
9  */
10 
11 #include "config.h"
12 
13 #include <sys/cdefs.h>
14 #if 0
15 #ifndef lint
16 static const char sccsid[] = "Id: delete.c,v 10.17 2001/06/25 15:19:09 skimo Exp  (Berkeley) Date: 2001/06/25 15:19:09 ";
17 #endif /* not lint */
18 #else
19 __RCSID("$NetBSD: delete.c,v 1.4 2017/11/22 12:47:30 rin Exp $");
20 #endif
21 
22 #include <sys/types.h>
23 #include <sys/queue.h>
24 
25 #include <bitstring.h>
26 #include <errno.h>
27 #include <limits.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <string.h>
31 
32 #include "common.h"
33 
34 /*
35  * del --
36  *	Delete a range of text.
37  *
38  * PUBLIC: int del __P((SCR *, MARK *, MARK *, int));
39  */
40 int
del(SCR * sp,MARK * fm,MARK * tm,int lmode)41 del(SCR *sp, MARK *fm, MARK *tm, int lmode)
42 {
43 	db_recno_t lno;
44 	size_t blen, len, nlen, tlen;
45 	CHAR_T *bp, *p;
46 	int eof, rval;
47 
48 	bp = NULL;
49 
50 	/* Case 1 -- delete in line mode. */
51 	if (lmode) {
52 		for (lno = tm->lno; lno >= fm->lno; --lno) {
53 			if (db_delete(sp, lno))
54 				return (1);
55 			++sp->rptlines[L_DELETED];
56 			if (lno % INTERRUPT_CHECK == 0 && INTERRUPTED(sp))
57 				break;
58 		}
59 		goto done;
60 	}
61 
62 	/*
63 	 * Case 2 -- delete to EOF.  This is a special case because it's
64 	 * easier to pick it off than try and find it in the other cases.
65  	 */
66 	if (db_last(sp, &lno))
67 		return (1);
68 	if (tm->lno >= lno) {
69 		if (tm->lno == lno) {
70 			if (db_get(sp, lno, DBG_FATAL, &p, &len))
71 				return (1);
72 			eof = tm->cno != ENTIRE_LINE && tm->cno >= len ? 1 : 0;
73 		} else
74 			eof = 1;
75 		if (eof) {
76 			for (lno = tm->lno; lno > fm->lno; --lno) {
77 				if (db_delete(sp, lno))
78 					return (1);
79 				++sp->rptlines[L_DELETED];
80 				if (lno %
81 				    INTERRUPT_CHECK == 0 && INTERRUPTED(sp))
82 					break;
83 			}
84 			if (db_get(sp, fm->lno, DBG_FATAL, &p, &len))
85 				return (1);
86 			GET_SPACE_RETW(sp, bp, blen, fm->cno);
87 			MEMCPYW(bp, p, fm->cno);
88 			if (db_set(sp, fm->lno, bp, fm->cno))
89 				return (1);
90 			goto done;
91 		}
92 	}
93 
94 	/* Case 3 -- delete within a single line. */
95 	if (tm->lno == fm->lno) {
96 		if (db_get(sp, fm->lno, DBG_FATAL, &p, &len))
97 			return (1);
98 		if (len != 0) {
99 			GET_SPACE_RETW(sp, bp, blen, len);
100 			if (fm->cno != 0)
101 				MEMCPYW(bp, p, fm->cno);
102 			MEMCPYW(bp + fm->cno, p + (tm->cno + 1),
103 				len - (tm->cno + 1));
104 			if (db_set(sp, fm->lno,
105 			    bp, len - ((tm->cno - fm->cno) + 1)))
106 				goto err;
107 		}
108 		goto done;
109 	}
110 
111 	/*
112 	 * Case 4 -- delete over multiple lines.
113 	 *
114 	 * Copy the start partial line into place.
115 	 */
116 	if ((tlen = fm->cno) != 0) {
117 		if (db_get(sp, fm->lno, DBG_FATAL, &p, NULL))
118 			return (1);
119 		GET_SPACE_RETW(sp, bp, blen, tlen + 256);
120 		MEMCPYW(bp, p, tlen);
121 	}
122 
123 	/* Copy the end partial line into place. */
124 	if (db_get(sp, tm->lno, DBG_FATAL, &p, &len))
125 		goto err;
126 	if (len != 0 && tm->cno != len - 1) {
127 		/*
128 		 * XXX
129 		 * We can overflow memory here, if the total length is greater
130 		 * than SIZE_T_MAX.  The only portable way I've found to test
131 		 * is depending on the overflow being less than the value.
132 		 */
133 		nlen = (len - (tm->cno + 1)) + tlen;
134 		if (tlen > nlen) {
135 			msgq(sp, M_ERR, "002|Line length overflow");
136 			goto err;
137 		}
138 		if (tlen == 0) {
139 			GET_SPACE_RETW(sp, bp, blen, nlen);
140 		} else
141 			ADD_SPACE_RETW(sp, bp, blen, nlen);
142 
143 		MEMCPYW(bp + tlen, p + (tm->cno + 1), len - (tm->cno + 1));
144 		tlen += len - (tm->cno + 1);
145 	}
146 
147 	/* Set the current line. */
148 	if (db_set(sp, fm->lno, bp, tlen))
149 		goto err;
150 
151 	/* Delete the last and intermediate lines. */
152 	for (lno = tm->lno; lno > fm->lno; --lno) {
153 		if (db_delete(sp, lno))
154 			goto err;
155 		++sp->rptlines[L_DELETED];
156 		if (lno % INTERRUPT_CHECK == 0 && INTERRUPTED(sp))
157 			break;
158 	}
159 
160 done:	rval = 0;
161 	if (0)
162 err:		rval = 1;
163 	if (bp != NULL)
164 		FREE_SPACEW(sp, bp, blen);
165 	return (rval);
166 }
167