1 /* $OpenBSD: delete.c,v 1.7 2002/02/16 21:27:56 millert 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 #ifndef lint 15 static const char sccsid[] = "@(#)delete.c 10.12 (Berkeley) 10/23/96"; 16 #endif /* not lint */ 17 18 #include <sys/types.h> 19 #include <sys/queue.h> 20 21 #include <bitstring.h> 22 #include <errno.h> 23 #include <limits.h> 24 #include <stdio.h> 25 #include <stdlib.h> 26 #include <string.h> 27 28 #include "common.h" 29 30 /* 31 * del -- 32 * Delete a range of text. 33 * 34 * PUBLIC: int del(SCR *, MARK *, MARK *, int); 35 */ 36 int 37 del(sp, fm, tm, lmode) 38 SCR *sp; 39 MARK *fm, *tm; 40 int lmode; 41 { 42 recno_t lno; 43 size_t blen, len, nlen, tlen; 44 char *bp, *p; 45 int eof, rval; 46 47 bp = NULL; 48 49 /* Case 1 -- delete in line mode. */ 50 if (lmode) { 51 for (lno = tm->lno; lno >= fm->lno; --lno) { 52 if (db_delete(sp, lno)) 53 return (1); 54 ++sp->rptlines[L_DELETED]; 55 if (lno % INTERRUPT_CHECK == 0 && INTERRUPTED(sp)) 56 break; 57 } 58 goto done; 59 } 60 61 /* 62 * Case 2 -- delete to EOF. This is a special case because it's 63 * easier to pick it off than try and find it in the other cases. 64 */ 65 if (db_last(sp, &lno)) 66 return (1); 67 if (tm->lno >= lno) { 68 if (tm->lno == lno) { 69 if (db_get(sp, lno, DBG_FATAL, &p, &len)) 70 return (1); 71 eof = tm->cno != -1 && tm->cno >= len ? 1 : 0; 72 } else 73 eof = 1; 74 if (eof) { 75 for (lno = tm->lno; lno > fm->lno; --lno) { 76 if (db_delete(sp, lno)) 77 return (1); 78 ++sp->rptlines[L_DELETED]; 79 if (lno % 80 INTERRUPT_CHECK == 0 && INTERRUPTED(sp)) 81 break; 82 } 83 if (db_get(sp, fm->lno, DBG_FATAL, &p, &len)) 84 return (1); 85 GET_SPACE_RET(sp, bp, blen, fm->cno); 86 memcpy(bp, p, fm->cno); 87 if (db_set(sp, fm->lno, bp, fm->cno)) 88 return (1); 89 goto done; 90 } 91 } 92 93 /* Case 3 -- delete within a single line. */ 94 if (tm->lno == fm->lno) { 95 if (db_get(sp, fm->lno, DBG_FATAL, &p, &len)) 96 return (1); 97 GET_SPACE_RET(sp, bp, blen, len); 98 if (fm->cno != 0) 99 memcpy(bp, p, fm->cno); 100 memcpy(bp + fm->cno, p + (tm->cno + 1), len - (tm->cno + 1)); 101 if (db_set(sp, fm->lno, 102 bp, len - ((tm->cno - fm->cno) + 1))) 103 goto err; 104 goto done; 105 } 106 107 /* 108 * Case 4 -- delete over multiple lines. 109 * 110 * Copy the start partial line into place. 111 */ 112 if ((tlen = fm->cno) != 0) { 113 if (db_get(sp, fm->lno, DBG_FATAL, &p, NULL)) 114 return (1); 115 GET_SPACE_RET(sp, bp, blen, tlen + 256); 116 memcpy(bp, p, tlen); 117 } 118 119 /* Copy the end partial line into place. */ 120 if (db_get(sp, tm->lno, DBG_FATAL, &p, &len)) 121 goto err; 122 if (len != 0 && tm->cno != len - 1) { 123 /* 124 * XXX 125 * We can overflow memory here, if the total length is greater 126 * than SIZE_T_MAX. The only portable way I've found to test 127 * is depending on the overflow being less than the value. 128 */ 129 nlen = (len - (tm->cno + 1)) + tlen; 130 if (tlen > nlen) { 131 msgq(sp, M_ERR, "002|Line length overflow"); 132 goto err; 133 } 134 if (tlen == 0) { 135 GET_SPACE_RET(sp, bp, blen, nlen); 136 } else 137 ADD_SPACE_RET(sp, bp, blen, nlen); 138 139 memcpy(bp + tlen, p + (tm->cno + 1), len - (tm->cno + 1)); 140 tlen += len - (tm->cno + 1); 141 } 142 143 /* Set the current line. */ 144 if (db_set(sp, fm->lno, bp, tlen)) 145 goto err; 146 147 /* Delete the last and intermediate lines. */ 148 for (lno = tm->lno; lno > fm->lno; --lno) { 149 if (db_delete(sp, lno)) 150 goto err; 151 ++sp->rptlines[L_DELETED]; 152 if (lno % INTERRUPT_CHECK == 0 && INTERRUPTED(sp)) 153 break; 154 } 155 156 done: rval = 0; 157 if (0) 158 err: rval = 1; 159 if (bp != NULL) 160 FREE_SPACE(sp, bp, blen); 161 return (rval); 162 } 163