common/vi_db1.c

   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 #ifndef lint
  13 static const char sccsid[] = "$Id: db1.c,v 10.1 2002/03/09 12:53:57 skimo Exp $ (Berkeley) $Date: 2002/03/09 12:53:57 $";
  14 #endif /* not lint */
  15
  16 #include <sys/types.h>
  17 #include <sys/queue.h>
  18 #include <sys/time.h>
  19 #include <sys/stat.h>
  20
  21 #include <bitstring.h>
  22 #include <errno.h>
  23 #include <fcntl.h>
  24 #include <limits.h>
  25 #include <stdio.h>
  26 #include <string.h>
  27
  28 #include "common.h"
  29 #include "../vi/vi.h"
  30
  31 /*
  32  * db_eget --
  33  *      Front-end to db_get, special case handling for empty files.
  34  *
  35  * PUBLIC: int db_eget __P((SCR *, db_recno_t, CHAR_T **, size_t *, int *));
  36  */
  37 int
  38 db_eget(SCR *sp, db_recno_t lno, CHAR_T **pp, size_t *lenp, int *isemptyp)
  39
  40                                                 /* Line number. */
  41                                                 /* Pointer store. */
  42                                                 /* Length store. */
  43
  44 {
  45         db_recno_t l1;
  46
  47         if (isemptyp != NULL)
  48                 *isemptyp = 0;
  49
  50         /* If the line exists, simply return it. */
  51         if (!db_get(sp, lno, 0, pp, lenp))
  52                 return (0);
  53
  54         /*
  55          * If the user asked for line 0 or line 1, i.e. the only possible
  56          * line in an empty file, find the last line of the file; db_last
  57          * fails loudly.
  58          */
  59         if ((lno == 0 || lno == 1) && db_last(sp, &l1))
  60                 return (1);
  61
  62         /* If the file isn't empty, fail loudly. */
  63         if ((lno != 0 && lno != 1) || l1 != 0) {
  64                 db_err(sp, lno);
  65                 return (1);
  66         }
  67
  68         if (isemptyp != NULL)
  69                 *isemptyp = 1;
  70
  71         return (1);
  72 }
  73
  74 /*
  75  * db_get --
  76  *      Look in the text buffers for a line, followed by the cache, followed
  77  *      by the database.
  78  *
  79  * PUBLIC: int db_get __P((SCR *, db_recno_t, u_int32_t, CHAR_T **, size_t *));
  80  */
  81 int
  82 db_get(SCR *sp, db_recno_t lno, u_int32_t flags, CHAR_T **pp, size_t *lenp)
  83
  84                                                 /* Line number. */
  85
  86                                                 /* Pointer store. */
  87                                                 /* Length store. */
  88 {
  89         DBT data, key;
  90         EXF *ep;
  91         TEXT *tp;
  92         db_recno_t l1, l2;
  93         CHAR_T *wp;
  94         size_t wlen;
  95         size_t nlen;
  96
  97         /*
  98          * The underlying recno stuff handles zero by returning NULL, but
  99          * have to have an OOB condition for the look-aside into the input
 100          * buffer anyway.
 101          */
 102         if (lno == 0)
 103                 goto err1;
 104
 105         /* Check for no underlying file. */
 106         if ((ep = sp->ep) == NULL) {
 107                 ex_emsg(sp, NULL, EXM_NOFILEYET);
 108                 goto err3;
 109         }
 110
 111         if (LF_ISSET(DBG_NOCACHE))
 112                 goto nocache;
 113
 114         /*
 115          * Look-aside into the TEXT buffers and see if the line we want
 116          * is there.
 117          */
 118         if (F_ISSET(sp, SC_TINPUT)) {
 119                 l1 = ((TEXT *)sp->tiq.cqh_first)->lno;
 120                 l2 = ((TEXT *)sp->tiq.cqh_last)->lno;
 121                 if (l1 <= lno && l2 >= lno) {
 122 #if defined(DEBUG) && 0
 123                         vtrace(sp,
 124                             "retrieve TEXT buffer line %lu\n", (u_long)lno);
 125 #endif
 126                         for (tp = sp->tiq.cqh_first;
 127                             tp->lno != lno; tp = tp->q.cqe_next);
 128                         if (lenp != NULL)
 129                                 *lenp = tp->len;
 130                         if (pp != NULL)
 131                                 *pp = tp->lb;
 132                         return (0);
 133                 }
 134                 /*
 135                  * Adjust the line number for the number of lines used
 136                  * by the text input buffers.
 137                  */
 138                 if (lno > l2)
 139                         lno -= l2 - l1;
 140         }
 141
 142         /* Look-aside into the cache, and see if the line we want is there. */
 143         if (lno == sp->c_lno) {
 144 #if defined(DEBUG) && 0
 145                 vtrace(sp, "retrieve cached line %lu\n", (u_long)lno);
 146 #endif
 147                 if (lenp != NULL)
 148                         *lenp = sp->c_len;
 149                 if (pp != NULL)
 150                         *pp = sp->c_lp;
 151                 return (0);
 152         }
 153         sp->c_lno = OOBLNO;
 154
 155 nocache:
 156         nlen = 1024;
 157 retry:
 158         /* data.size contains length in bytes */
 159         BINC_GOTO(sp, CHAR_T, sp->c_lp, sp->c_blen, nlen);
 160
 161         /* Get the line from the underlying database. */
 162         key.data = &lno;
 163         key.size = sizeof(lno);
 164         switch (ep->db->get(ep->db, &key, &data, 0)) {
 165         case -1:
 166                 goto err2;
 167         case 1:
 168 err1:           if (LF_ISSET(DBG_FATAL))
 169 err2:                   db_err(sp, lno);
 170 alloc_err:
 171 err3:           if (lenp != NULL)
 172                         *lenp = 0;
 173                 if (pp != NULL)
 174                         *pp = NULL;
 175                 return (1);
 176         case 0:
 177                 if (data.size > nlen) {
 178                         nlen = data.size;
 179                         goto retry;
 180                 } else
 181                         memcpy(sp->c_lp, data.data, nlen);
 182         }
 183
 184         if (FILE2INT(sp, data.data, data.size, wp, wlen)) {
 185             if (!F_ISSET(sp, SC_CONV_ERROR)) {
 186                 F_SET(sp, SC_CONV_ERROR);
 187                 msgq(sp, M_ERR, "324|Conversion error on line %d", lno);
 188             }
 189             goto err3;
 190         }
 191
 192         /* Reset the cache. */
 193         if (wp != data.data) {
 194             BINC_GOTOW(sp, sp->c_lp, sp->c_blen, wlen);
 195             MEMCPYW(sp->c_lp, wp, wlen);
 196         }
 197         sp->c_lno = lno;
 198         sp->c_len = wlen;
 199
 200 #if defined(DEBUG) && 0
 201         vtrace(sp, "retrieve DB line %lu\n", (u_long)lno);
 202 #endif
 203         if (lenp != NULL)
 204                 *lenp = wlen;
 205         if (pp != NULL)
 206                 *pp = sp->c_lp;
 207         return (0);
 208 }
 209
 210 /*
 211  * db_delete --
 212  *      Delete a line from the file.
 213  *
 214  * PUBLIC: int db_delete __P((SCR *, db_recno_t));
 215  */
 216 int
 217 db_delete(SCR *sp, db_recno_t lno)
 218 {
 219         DBT key;
 220         EXF *ep;
 221
 222 #if defined(DEBUG) && 0
 223         vtrace(sp, "delete line %lu\n", (u_long)lno);
 224 #endif
 225         /* Check for no underlying file. */
 226         if ((ep = sp->ep) == NULL) {
 227                 ex_emsg(sp, NULL, EXM_NOFILEYET);
 228                 return (1);
 229         }
 230         if (ep->l_win && ep->l_win != sp->wp) {
 231                 ex_emsg(sp, NULL, EXM_LOCKED);
 232                 return 1;
 233         }
 234
 235         /* Update marks, @ and global commands. */
 236         if (mark_insdel(sp, LINE_DELETE, lno))
 237                 return (1);
 238         if (ex_g_insdel(sp, LINE_DELETE, lno))
 239                 return (1);
 240
 241         /* Log change. */
 242         log_line(sp, lno, LOG_LINE_DELETE_B);
 243
 244         /* Update file. */
 245         key.data = &lno;
 246         key.size = sizeof(lno);
 247         sp->db_error = ep->db->del(ep->db, &key, 0);
 248         if (sp->db_error != 0) {
 249                 if (sp->db_error == -1)
 250                         sp->db_error = errno;
 251
 252                 msgq(sp, M_DBERR, "003|unable to delete line %lu",
 253                     (u_long)lno);
 254                 return (1);
 255         }
 256
 257         /* Flush the cache, update line count, before screen update. */
 258         update_cache(sp, LINE_DELETE, lno);
 259
 260         /* File now modified. */
 261         if (F_ISSET(ep, F_FIRSTMODIFY))
 262                 (void)rcv_init(sp);
 263         F_SET(ep, F_MODIFIED);
 264
 265         /* Log after change. */
 266         log_line(sp, lno, LOG_LINE_DELETE_F);
 267
 268         /* Update screen. */
 269         return (scr_update(sp, lno, LINE_DELETE, 1));
 270 }
 271
 272 /*
 273  * db_append --
 274  *      Append a line into the file.
 275  *
 276  * PUBLIC: int db_append __P((SCR *, int, db_recno_t, CHAR_T *, size_t));
 277  */
 278 int
 279 db_append(SCR *sp, int update, db_recno_t lno, CHAR_T *p, size_t len)
 280 {
 281         DBT data, key;
 282         EXF *ep;
 283         char *fp;
 284         size_t flen;
 285         int rval;
 286
 287 #if defined(DEBUG) && 0
 288         vtrace(sp, "append to %lu: len %u {%.*s}\n", lno, len, MIN(len, 20), p);
 289 #endif
 290         /* Check for no underlying file. */
 291         if ((ep = sp->ep) == NULL) {
 292                 ex_emsg(sp, NULL, EXM_NOFILEYET);
 293                 return (1);
 294         }
 295         if (ep->l_win && ep->l_win != sp->wp) {
 296                 ex_emsg(sp, NULL, EXM_LOCKED);
 297                 return 1;
 298         }
 299
 300         /* Log before change. */
 301         log_line(sp, lno + 1, LOG_LINE_APPEND_B);
 302
 303         INT2FILE(sp, p, len, fp, flen);
 304
 305         /* Update file. */
 306         key.data = &lno;
 307         key.size = sizeof(lno);
 308         data.data = fp;
 309         data.size = flen;
 310         if (ep->db->put(ep->db, &key, &data, R_IAFTER)) {
 311                 msgq(sp, M_DBERR, "004|unable to append to line %lu",
 312                         (u_long)lno);
 313                 return (1);
 314         }
 315
 316         /* Flush the cache, update line count, before screen update. */
 317         update_cache(sp, LINE_INSERT, lno);
 318
 319         /* File now dirty. */
 320         if (F_ISSET(ep, F_FIRSTMODIFY))
 321                 (void)rcv_init(sp);
 322         F_SET(ep, F_MODIFIED);
 323
 324         /* Log after change. */
 325         log_line(sp, lno + 1, LOG_LINE_APPEND_F);
 326
 327         /* Update marks, @ and global commands. */
 328         rval = 0;
 329         if (mark_insdel(sp, LINE_INSERT, lno + 1))
 330                 rval = 1;
 331         if (ex_g_insdel(sp, LINE_INSERT, lno + 1))
 332                 rval = 1;
 333
 334         /*
 335          * Update screen.
 336          *
 337          * XXX
 338          * Nasty hack.  If multiple lines are input by the user, they aren't
 339          * committed until an <ESC> is entered.  The problem is the screen was
 340          * updated/scrolled as each line was entered.  So, when this routine
 341          * is called to copy the new lines from the cut buffer into the file,
 342          * it has to know not to update the screen again.
 343          */
 344         return (scr_update(sp, lno, LINE_APPEND, update) || rval);
 345 }
 346
 347 /*
 348  * db_insert --
 349  *      Insert a line into the file.
 350  *
 351  * PUBLIC: int db_insert __P((SCR *, db_recno_t, CHAR_T *, size_t));
 352  */
 353 int
 354 db_insert(SCR *sp, db_recno_t lno, CHAR_T *p, size_t len)
 355 {
 356         DBT data, key;
 357         EXF *ep;
 358         char *fp;
 359         size_t flen;
 360         int rval;
 361
 362 #if defined(DEBUG) && 0
 363         vtrace(sp, "insert before %lu: len %lu {%.*s}\n",
 364             (u_long)lno, (u_long)len, MIN(len, 20), p);
 365 #endif
 366         /* Check for no underlying file. */
 367         if ((ep = sp->ep) == NULL) {
 368                 ex_emsg(sp, NULL, EXM_NOFILEYET);
 369                 return (1);
 370         }
 371         if (ep->l_win && ep->l_win != sp->wp) {
 372                 ex_emsg(sp, NULL, EXM_LOCKED);
 373                 return 1;
 374         }
 375
 376         /* Log before change. */
 377         log_line(sp, lno, LOG_LINE_APPEND_B);
 378
 379         INT2FILE(sp, p, len, fp, flen);
 380
 381         /* Update file. */
 382         key.data = &lno;
 383         key.size = sizeof(lno);
 384         data.data = fp;
 385         data.size = flen;
 386         if (ep->db->put(ep->db, &key, &data, R_IBEFORE)) {
 387                 msgq(sp, M_SYSERR,
 388                     "005|unable to insert at line %lu", (u_long)lno);
 389                 return (1);
 390         }
 391
 392         /* Flush the cache, update line count, before screen update. */
 393         update_cache(sp, LINE_INSERT, lno);
 394
 395         /* File now dirty. */
 396         if (F_ISSET(ep, F_FIRSTMODIFY))
 397                 (void)rcv_init(sp);
 398         F_SET(ep, F_MODIFIED);
 399
 400         /* Log after change. */
 401         log_line(sp, lno, LOG_LINE_APPEND_F);
 402
 403         /* Update marks, @ and global commands. */
 404         rval = 0;
 405         if (mark_insdel(sp, LINE_INSERT, lno))
 406                 rval = 1;
 407         if (ex_g_insdel(sp, LINE_INSERT, lno))
 408                 rval = 1;
 409
 410         /* Update screen. */
 411         return (scr_update(sp, lno, LINE_INSERT, 1) || rval);
 412 }
 413
 414 /*
 415  * db_set --
 416  *      Store a line in the file.
 417  *
 418  * PUBLIC: int db_set __P((SCR *, db_recno_t, CHAR_T *, size_t));
 419  */
 420 int
 421 db_set(SCR *sp, db_recno_t lno, CHAR_T *p, size_t len)
 422 {
 423         DBT data, key;
 424         EXF *ep;
 425         char *fp;
 426         size_t flen;
 427
 428 #if defined(DEBUG) && 0
 429         vtrace(sp, "replace line %lu: len %lu {%.*s}\n",
 430             (u_long)lno, (u_long)len, MIN(len, 20), p);
 431 #endif
 432         /* Check for no underlying file. */
 433         if ((ep = sp->ep) == NULL) {
 434                 ex_emsg(sp, NULL, EXM_NOFILEYET);
 435                 return (1);
 436         }
 437         if (ep->l_win && ep->l_win != sp->wp) {
 438                 ex_emsg(sp, NULL, EXM_LOCKED);
 439                 return 1;
 440         }
 441
 442         /* Log before change. */
 443         log_line(sp, lno, LOG_LINE_RESET_B);
 444
 445         INT2FILE(sp, p, len, fp, flen);
 446
 447         /* Update file. */
 448         key.data = &lno;
 449         key.size = sizeof(lno);
 450         data.data = fp;
 451         data.size = flen;
 452         sp->db_error =
 453                 ep->db->put(ep->db, &key, &data, 0);
 454         if (sp->db_error != 0) {
 455                 if (sp->db_error == -1)
 456                         sp->db_error = errno;
 457
 458                 msgq(sp, M_DBERR, "006|unable to store line %lu", (u_long)lno);
 459                 return (1);
 460         }
 461
 462         /* Flush the cache, before logging or screen update. */
 463         update_cache(sp, LINE_RESET, lno);
 464
 465         /* File now dirty. */
 466         if (F_ISSET(ep, F_FIRSTMODIFY))
 467                 (void)rcv_init(sp);
 468         F_SET(ep, F_MODIFIED);
 469
 470         /* Log after change. */
 471         log_line(sp, lno, LOG_LINE_RESET_F);
 472
 473         /* Update screen. */
 474         return (scr_update(sp, lno, LINE_RESET, 1));
 475 }
 476
 477 /*
 478  * db_exist --
 479  *      Return if a line exists.
 480  *
 481  * PUBLIC: int db_exist __P((SCR *, db_recno_t));
 482  */
 483 int
 484 db_exist(SCR *sp, db_recno_t lno)
 485 {
 486         EXF *ep;
 487
 488         /* Check for no underlying file. */
 489         if ((ep = sp->ep) == NULL) {
 490                 ex_emsg(sp, NULL, EXM_NOFILEYET);
 491                 return (1);
 492         }
 493
 494         if (lno == OOBLNO)
 495                 return (0);
 496
 497         /*
 498          * Check the last-line number cache.  Adjust the cached line
 499          * number for the lines used by the text input buffers.
 500          */
 501         if (ep->c_nlines != OOBLNO)
 502                 return (lno <= (F_ISSET(sp, SC_TINPUT) ?
 503                     ep->c_nlines + (((TEXT *)sp->tiq.cqh_last)->lno -
 504                     ((TEXT *)sp->tiq.cqh_first)->lno) : ep->c_nlines));
 505
 506         /* Go get the line. */
 507         return (!db_get(sp, lno, 0, NULL, NULL));
 508 }
 509
 510 /*
 511  * db_last --
 512  *      Return the number of lines in the file.
 513  *
 514  * PUBLIC: int db_last __P((SCR *, db_recno_t *));
 515  */
 516 int
 517 db_last(SCR *sp, db_recno_t *lnop)
 518 {
 519         DBT data, key;
 520         EXF *ep;
 521         db_recno_t lno;
 522         CHAR_T *wp;
 523         size_t wlen;
 524
 525         /* Check for no underlying file. */
 526         if ((ep = sp->ep) == NULL) {
 527                 ex_emsg(sp, NULL, EXM_NOFILEYET);
 528                 return (1);
 529         }
 530
 531         /*
 532          * Check the last-line number cache.  Adjust the cached line
 533          * number for the lines used by the text input buffers.
 534          */
 535         if (ep->c_nlines != OOBLNO) {
 536                 *lnop = ep->c_nlines;
 537                 if (F_ISSET(sp, SC_TINPUT))
 538                         *lnop += ((TEXT *)sp->tiq.cqh_last)->lno -
 539                             ((TEXT *)sp->tiq.cqh_first)->lno;
 540                 return (0);
 541         }
 542
 543         key.data = &lno;
 544         key.size = sizeof(lno);
 545
 546         sp->db_error = ep->db->seq(ep->db, &key, &data, R_LAST);
 547         switch (sp->db_error) {
 548         case 1:
 549                 *lnop = 0;
 550                 return (0);
 551         case -1:
 552                 sp->db_error = errno;
 553 alloc_err:
 554                 msgq(sp, M_DBERR, "007|unable to get last line");
 555                 *lnop = 0;
 556                 return (1);
 557         case 0:
 558                 ;
 559         }
 560
 561         memcpy(&lno, key.data, sizeof(lno));
 562
 563         if (lno != sp->c_lno) {
 564             FILE2INT(sp, data.data, data.size, wp, wlen);
 565
 566             /* Fill the cache. */
 567             BINC_GOTOW(sp, sp->c_lp, sp->c_blen, wlen);
 568             MEMCPYW(sp->c_lp, wp, wlen);
 569             sp->c_lno = lno;
 570             sp->c_len = wlen;
 571         }
 572         ep->c_nlines = lno;
 573
 574         /* Return the value. */
 575         *lnop = (F_ISSET(sp, SC_TINPUT) &&
 576             ((TEXT *)sp->tiq.cqh_last)->lno > lno ?
 577             ((TEXT *)sp->tiq.cqh_last)->lno : lno);
 578         return (0);
 579 }
 580
 581 /*
 582  * db_err --
 583  *      Report a line error.
 584  *
 585  * PUBLIC: void db_err __P((SCR *, db_recno_t));
 586  */
 587 void
 588 db_err(SCR *sp, db_recno_t lno)
 589 {
 590         msgq(sp, M_ERR,
 591             "008|Error: unable to retrieve line %lu", (u_long)lno);
 592 }
 593
 594 /*
 595  * scr_update --
 596  *      Update all of the screens that are backed by the file that
 597  *      just changed.
 598  */
 599 int
 600 scr_update(SCR *sp, db_recno_t lno, lnop_t op, int current)
 601 {
 602         EXF *ep;
 603         SCR *tsp;
 604         WIN *wp;
 605
 606         if (F_ISSET(sp, SC_EX))
 607                 return (0);
 608
 609         /* XXXX goes outside of window */
 610         ep = sp->ep;
 611         if (ep->refcnt != 1)
 612                 for (wp = sp->gp->dq.cqh_first; wp != (void *)&sp->gp->dq;
 613                     wp = wp->q.cqe_next)
 614                         for (tsp = wp->scrq.cqh_first;
 615                             tsp != (void *)&wp->scrq; tsp = tsp->q.cqe_next)
 616                         if (sp != tsp && tsp->ep == ep)
 617                                 if (vs_change(tsp, lno, op))
 618                                         return (1);
 619         return (current ? vs_change(sp, lno, op) : 0);
 620 }
 621
 622 /*
 623  * PUBLIC: void update_cache __P((SCR *sp, lnop_t op, db_recno_t lno));
 624  */
 625 void
 626 update_cache(SCR *sp, lnop_t op, db_recno_t lno)
 627 {
 628         SCR* scrp;
 629         EXF *ep;
 630
 631         ep = sp->ep;
 632
 633         /* Flush the cache, update line count, before screen update. */
 634         /* The flushing is probably not needed, since it was incorrect
 635          * for db_insert.  It might be better to adjust it, like
 636          * marks, @ and global
 637          */
 638         for (scrp = ep->scrq.cqh_first; scrp != (void *)&ep->scrq;
 639             scrp = scrp->eq.cqe_next)
 640                 switch (op) {
 641                 case LINE_INSERT:
 642                 case LINE_DELETE:
 643                         if (lno <= scrp->c_lno)
 644                                 scrp->c_lno = OOBLNO;
 645                         break;
 646                 case LINE_RESET:
 647                         if (lno == scrp->c_lno)
 648                                 scrp->c_lno = OOBLNO;
 649                         break;
 650                 }
 651
 652         if (ep->c_nlines != OOBLNO)
 653                 switch (op) {
 654                 case LINE_INSERT:
 655                         ++ep->c_nlines;
 656                         break;
 657                 case LINE_DELETE:
 658                         --ep->c_nlines;
 659                         break;
 660                 }
 661 }
 662
 663 /*
 664  * PUBLIC: int db_msg_open __P((SCR *, char *, DB **));
 665  */
 666 int db_msg_open(SCR *sp, char *file, DB **dbp)
 667 {
 668         *dbp = dbopen(file, O_NONBLOCK | O_RDONLY, 0, DB_RECNO, NULL);
 669
 670         return *dbp == NULL;
 671 }
 672
 673 /*
 674  * PUBLIC: int db_init __P((SCR *, EXF *, char *, char *, size_t, int *));
 675  */
 676 int
 677 db_init(SCR *sp, EXF *ep, char *rcv_name, char *oname, size_t psize, int *open_err)
 678 {
 679         RECNOINFO oinfo;
 680
 681         memset(&oinfo, 0, sizeof(RECNOINFO));
 682         oinfo.bval = '\n';                      /* Always set. */
 683         oinfo.psize = psize;
 684         oinfo.flags = R_SNAPSHOT;
 685         if (rcv_name)
 686                 oinfo.bfname = ep->rcv_path;
 687
 688 #define _DB_OPEN_MODE   S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH
 689
 690         ep->db = dbopen(rcv_name == NULL ? oname : NULL,
 691             O_NONBLOCK | O_RDONLY, _DB_OPEN_MODE, DB_RECNO, &oinfo);
 692
 693         if (!ep->db) {
 694                 msgq_str(sp,
 695                     M_DBERR, rcv_name == NULL ? oname : rcv_name, "%s");
 696                 /*
 697                  * !!!
 698                  * Historically, vi permitted users to edit files that couldn't
 699                  * be read.  This isn't useful for single files from a command
 700                  * line, but it's quite useful for "vi *.c", since you can skip
 701                  * past files that you can't read.
 702                  */
 703                 ep->db = NULL; /* Don't close it; it wasn't opened */
 704
 705                 *open_err = 1;
 706                 return 1;
 707         }
 708
 709         return 0;
 710 }
 711
 712 char *
 713 db_strerror(int error)
 714 {
 715         return error > 0 ? strerror(error) : "record not found";
 716 }