1 /* $OpenBSD: delete.c,v 1.8 2009/10/27 23:59:47 deraadt Exp $ */
2
3 /*-
4 * Copyright (c) 1992, 1993, 1994
5 * The Regents of the University of California. All rights reserved.
6 * Copyright (c) 1992, 1993, 1994, 1995, 1996
7 * Keith Bostic. All rights reserved.
8 *
9 * See the LICENSE file for redistribution information.
10 */
11
12 #include "config.h"
13
14 #include <sys/types.h>
15 #include <sys/queue.h>
16
17 #include <bitstring.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.h"
25
26 /*
27 * del --
28 * Delete a range of text.
29 *
30 * PUBLIC: int del(SCR *, MARK *, MARK *, int);
31 */
32 int
del(sp,fm,tm,lmode)33 del(sp, fm, tm, lmode)
34 SCR *sp;
35 MARK *fm, *tm;
36 int lmode;
37 {
38 recno_t lno;
39 size_t blen, len, nlen, tlen;
40 char *bp, *p;
41 int eof, rval;
42
43 bp = NULL;
44
45 /* Case 1 -- delete in line mode. */
46 if (lmode) {
47 for (lno = tm->lno; lno >= fm->lno; --lno) {
48 if (db_delete(sp, lno))
49 return (1);
50 ++sp->rptlines[L_DELETED];
51 if (lno % INTERRUPT_CHECK == 0 && INTERRUPTED(sp))
52 break;
53 }
54 goto done;
55 }
56
57 /*
58 * Case 2 -- delete to EOF. This is a special case because it's
59 * easier to pick it off than try and find it in the other cases.
60 */
61 if (db_last(sp, &lno))
62 return (1);
63 if (tm->lno >= lno) {
64 if (tm->lno == lno) {
65 if (db_get(sp, lno, DBG_FATAL, &p, &len))
66 return (1);
67 eof = tm->cno != -1 && tm->cno >= len ? 1 : 0;
68 } else
69 eof = 1;
70 if (eof) {
71 for (lno = tm->lno; lno > fm->lno; --lno) {
72 if (db_delete(sp, lno))
73 return (1);
74 ++sp->rptlines[L_DELETED];
75 if (lno %
76 INTERRUPT_CHECK == 0 && INTERRUPTED(sp))
77 break;
78 }
79 if (db_get(sp, fm->lno, DBG_FATAL, &p, &len))
80 return (1);
81 GET_SPACE_RET(sp, bp, blen, fm->cno);
82 memcpy(bp, p, fm->cno);
83 if (db_set(sp, fm->lno, bp, fm->cno))
84 return (1);
85 goto done;
86 }
87 }
88
89 /* Case 3 -- delete within a single line. */
90 if (tm->lno == fm->lno) {
91 if (db_get(sp, fm->lno, DBG_FATAL, &p, &len))
92 return (1);
93 GET_SPACE_RET(sp, bp, blen, len);
94 if (fm->cno != 0)
95 memcpy(bp, p, fm->cno);
96 memcpy(bp + fm->cno, p + (tm->cno + 1), len - (tm->cno + 1));
97 if (db_set(sp, fm->lno,
98 bp, len - ((tm->cno - fm->cno) + 1)))
99 goto err;
100 goto done;
101 }
102
103 /*
104 * Case 4 -- delete over multiple lines.
105 *
106 * Copy the start partial line into place.
107 */
108 if ((tlen = fm->cno) != 0) {
109 if (db_get(sp, fm->lno, DBG_FATAL, &p, NULL))
110 return (1);
111 GET_SPACE_RET(sp, bp, blen, tlen + 256);
112 memcpy(bp, p, tlen);
113 }
114
115 /* Copy the end partial line into place. */
116 if (db_get(sp, tm->lno, DBG_FATAL, &p, &len))
117 goto err;
118 if (len != 0 && tm->cno != len - 1) {
119 /*
120 * XXX
121 * We can overflow memory here, if the total length is greater
122 * than SIZE_T_MAX. The only portable way I've found to test
123 * is depending on the overflow being less than the value.
124 */
125 nlen = (len - (tm->cno + 1)) + tlen;
126 if (tlen > nlen) {
127 msgq(sp, M_ERR, "002|Line length overflow");
128 goto err;
129 }
130 if (tlen == 0) {
131 GET_SPACE_RET(sp, bp, blen, nlen);
132 } else
133 ADD_SPACE_RET(sp, bp, blen, nlen);
134
135 memcpy(bp + tlen, p + (tm->cno + 1), len - (tm->cno + 1));
136 tlen += len - (tm->cno + 1);
137 }
138
139 /* Set the current line. */
140 if (db_set(sp, fm->lno, bp, tlen))
141 goto err;
142
143 /* Delete the last and intermediate lines. */
144 for (lno = tm->lno; lno > fm->lno; --lno) {
145 if (db_delete(sp, lno))
146 goto err;
147 ++sp->rptlines[L_DELETED];
148 if (lno % INTERRUPT_CHECK == 0 && INTERRUPTED(sp))
149 break;
150 }
151
152 done: rval = 0;
153 if (0)
154 err: rval = 1;
155 if (bp != NULL)
156 FREE_SPACE(sp, bp, blen);
157 return (rval);
158 }
159