src/src/dbfn.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2018 */
   6 /* See the file NOTICE for conditions of use and distribution. */
   7
   8
   9 #include "exim.h"
  10
  11
  12 /* Functions for accessing Exim's hints database, which consists of a number of
  13 different DBM files. This module does not contain code for reading DBM files
  14 for (e.g.) alias expansion. That is all contained within the general search
  15 functions. As Exim now has support for several DBM interfaces, all the relevant
  16 functions are called as macros.
  17
  18 All the data in Exim's database is in the nature of *hints*. Therefore it
  19 doesn't matter if it gets destroyed by accident. These functions are not
  20 supposed to implement a "safe" database.
  21
  22 Keys are passed in as C strings, and the terminating zero *is* used when
  23 building the dbm files. This just makes life easier when scanning the files
  24 sequentially.
  25
  26 Synchronization is required on the database files, and this is achieved by
  27 means of locking on independent lock files. (Earlier attempts to lock on the
  28 DBM files themselves were never completely successful.) Since callers may in
  29 general want to do more than one read or write while holding the lock, there
  30 are separate open and close functions. However, the calling modules should
  31 arrange to hold the locks for the bare minimum of time. */
  32
  33
  34
  35 /*************************************************
  36 *         Berkeley DB error callback             *
  37 *************************************************/
  38
  39 /* For Berkeley DB >= 2, we can define a function to be called in case of DB
  40 errors. This should help with debugging strange DB problems, e.g. getting "File
  41 exists" when you try to open a db file. The API for this function was changed
  42 at DB release 4.3. */
  43
  44 #if defined(USE_DB) && defined(DB_VERSION_STRING)
  45 void
  46 #if DB_VERSION_MAJOR > 4 || (DB_VERSION_MAJOR == 4 && DB_VERSION_MINOR >= 3)
  47 dbfn_bdb_error_callback(const DB_ENV *dbenv, const char *pfx, const char *msg)
  48 {
  49 dbenv = dbenv;
  50 #else
  51 dbfn_bdb_error_callback(const char *pfx, char *msg)
  52 {
  53 #endif
  54 pfx = pfx;
  55 log_write(0, LOG_MAIN, "Berkeley DB error: %s", msg);
  56 }
  57 #endif
  58
  59
  60
  61
  62 /*************************************************
  63 *          Open and lock a database file         *
  64 *************************************************/
  65
  66 /* Used for accessing Exim's hints databases.
  67
  68 Arguments:
  69   name     The single-component name of one of Exim's database files.
  70   flags    Either O_RDONLY or O_RDWR, indicating the type of open required;
  71              O_RDWR implies "create if necessary"
  72   dbblock  Points to an open_db block to be filled in.
  73   lof      If TRUE, write to the log for actual open failures (locking failures
  74            are always logged).
  75
  76 Returns:   NULL if the open failed, or the locking failed. After locking
  77            failures, errno is zero.
  78
  79            On success, dbblock is returned. This contains the dbm pointer and
  80            the fd of the locked lock file.
  81
  82 There are some calls that use O_RDWR|O_CREAT for the flags. Having discovered
  83 this in December 2005, I'm not sure if this is correct or not, but for the
  84 moment I haven't changed them.
  85 */
  86
  87 open_db *
  88 dbfn_open(uschar *name, int flags, open_db *dbblock, BOOL lof)
  89 {
  90 int rc, save_errno;
  91 BOOL read_only = flags == O_RDONLY;
  92 BOOL created = FALSE;
  93 flock_t lock_data;
  94 uschar dirname[256], filename[256];
  95
  96 DEBUG(D_hints_lookup) acl_level++;
  97
  98 /* The first thing to do is to open a separate file on which to lock. This
  99 ensures that Exim has exclusive use of the database before it even tries to
 100 open it. Early versions tried to lock on the open database itself, but that
 101 gave rise to mysterious problems from time to time - it was suspected that some
 102 DB libraries "do things" on their open() calls which break the interlocking.
 103 The lock file is never written to, but we open it for writing so we can get a
 104 write lock if required. If it does not exist, we create it. This is done
 105 separately so we know when we have done it, because when running as root we
 106 need to change the ownership - see the bottom of this function. We also try to
 107 make the directory as well, just in case. We won't be doing this many times
 108 unnecessarily, because usually the lock file will be there. If the directory
 109 exists, there is no error. */
 110
 111 snprintf(CS dirname, sizeof(dirname), "%s/db", spool_directory);
 112 snprintf(CS filename, sizeof(filename), "%s/%s.lockfile", dirname, name);
 113
 114 if ((dbblock->lockfd = Uopen(filename, O_RDWR, EXIMDB_LOCKFILE_MODE)) < 0)
 115   {
 116   created = TRUE;
 117   (void)directory_make(spool_directory, US"db", EXIMDB_DIRECTORY_MODE, TRUE);
 118   dbblock->lockfd = Uopen(filename, O_RDWR|O_CREAT, EXIMDB_LOCKFILE_MODE);
 119   }
 120
 121 if (dbblock->lockfd < 0)
 122   {
 123   log_write(0, LOG_MAIN, "%s",
 124     string_open_failed(errno, "database lock file %s", filename));
 125   errno = 0;      /* Indicates locking failure */
 126   DEBUG(D_hints_lookup) acl_level--;
 127   return NULL;
 128   }
 129
 130 /* Now we must get a lock on the opened lock file; do this with a blocking
 131 lock that times out. */
 132
 133 lock_data.l_type = read_only? F_RDLCK : F_WRLCK;
 134 lock_data.l_whence = lock_data.l_start = lock_data.l_len = 0;
 135
 136 DEBUG(D_hints_lookup|D_retry|D_route|D_deliver)
 137   debug_printf_indent("locking %s\n", filename);
 138
 139 sigalrm_seen = FALSE;
 140 alarm(EXIMDB_LOCK_TIMEOUT);
 141 rc = fcntl(dbblock->lockfd, F_SETLKW, &lock_data);
 142 alarm(0);
 143
 144 if (sigalrm_seen) errno = ETIMEDOUT;
 145 if (rc < 0)
 146   {
 147   log_write(0, LOG_MAIN|LOG_PANIC, "Failed to get %s lock for %s: %s",
 148     read_only ? "read" : "write", filename,
 149     errno == ETIMEDOUT ? "timed out" : strerror(errno));
 150   (void)close(dbblock->lockfd);
 151   errno = 0;       /* Indicates locking failure */
 152   DEBUG(D_hints_lookup) acl_level--;
 153   return NULL;
 154   }
 155
 156 DEBUG(D_hints_lookup) debug_printf_indent("locked  %s\n", filename);
 157
 158 /* At this point we have an opened and locked separate lock file, that is,
 159 exclusive access to the database, so we can go ahead and open it. If we are
 160 expected to create it, don't do so at first, again so that we can detect
 161 whether we need to change its ownership (see comments about the lock file
 162 above.) There have been regular reports of crashes while opening hints
 163 databases - often this is caused by non-matching db.h and the library. To make
 164 it easy to pin this down, there are now debug statements on either side of the
 165 open call. */
 166
 167 snprintf(CS filename, sizeof(filename), "%s/%s", dirname, name);
 168 EXIM_DBOPEN(filename, dirname, flags, EXIMDB_MODE, &(dbblock->dbptr));
 169
 170 if (!dbblock->dbptr && errno == ENOENT && flags == O_RDWR)
 171   {
 172   DEBUG(D_hints_lookup)
 173     debug_printf_indent("%s appears not to exist: trying to create\n", filename);
 174   created = TRUE;
 175   EXIM_DBOPEN(filename, dirname, flags|O_CREAT, EXIMDB_MODE, &(dbblock->dbptr));
 176   }
 177
 178 save_errno = errno;
 179
 180 /* If we are running as root and this is the first access to the database, its
 181 files will be owned by root. We want them to be owned by exim. We detect this
 182 situation by noting above when we had to create the lock file or the database
 183 itself. Because the different dbm libraries use different extensions for their
 184 files, I don't know of any easier way of arranging this than scanning the
 185 directory for files with the appropriate base name. At least this deals with
 186 the lock file at the same time. Also, the directory will typically have only
 187 half a dozen files, so the scan will be quick.
 188
 189 This code is placed here, before the test for successful opening, because there
 190 was a case when a file was created, but the DBM library still returned NULL
 191 because of some problem. It also sorts out the lock file if that was created
 192 but creation of the database file failed. */
 193
 194 if (created && geteuid() == root_uid)
 195   {
 196   DIR *dd;
 197   struct dirent *ent;
 198   uschar *lastname = Ustrrchr(filename, '/') + 1;
 199   int namelen = Ustrlen(name);
 200
 201   *lastname = 0;
 202   dd = opendir(CS filename);
 203
 204   while ((ent = readdir(dd)))
 205     if (Ustrncmp(ent->d_name, name, namelen) == 0)
 206       {
 207       struct stat statbuf;
 208       Ustrcpy(lastname, ent->d_name);
 209       if (Ustat(filename, &statbuf) >= 0 && statbuf.st_uid != exim_uid)
 210         {
 211         DEBUG(D_hints_lookup) debug_printf_indent("ensuring %s is owned by exim\n", filename);
 212         if (Uchown(filename, exim_uid, exim_gid))
 213           DEBUG(D_hints_lookup) debug_printf_indent("failed setting %s to owned by exim\n", filename);
 214         }
 215       }
 216
 217   closedir(dd);
 218   }
 219
 220 /* If the open has failed, return NULL, leaving errno set. If lof is TRUE,
 221 log the event - also for debugging - but debug only if the file just doesn't
 222 exist. */
 223
 224 if (!dbblock->dbptr)
 225   {
 226   if (lof && save_errno != ENOENT)
 227     log_write(0, LOG_MAIN, "%s", string_open_failed(save_errno, "DB file %s",
 228         filename));
 229   else
 230     DEBUG(D_hints_lookup)
 231       debug_printf_indent("%s\n", CS string_open_failed(save_errno, "DB file %s",
 232           filename));
 233   (void)close(dbblock->lockfd);
 234   errno = save_errno;
 235   DEBUG(D_hints_lookup) acl_level--;
 236   return NULL;
 237   }
 238
 239 DEBUG(D_hints_lookup)
 240   debug_printf_indent("opened hints database %s: flags=%s\n", filename,
 241     flags == O_RDONLY ? "O_RDONLY"
 242     : flags == O_RDWR ? "O_RDWR"
 243     : flags == (O_RDWR|O_CREAT) ? "O_RDWR|O_CREAT"
 244     : "??");
 245
 246 /* Pass back the block containing the opened database handle and the open fd
 247 for the lock. */
 248
 249 return dbblock;
 250 }
 251
 252
 253
 254
 255 /*************************************************
 256 *         Unlock and close a database file       *
 257 *************************************************/
 258
 259 /* Closing a file automatically unlocks it, so after closing the database, just
 260 close the lock file.
 261
 262 Argument: a pointer to an open database block
 263 Returns:  nothing
 264 */
 265
 266 void
 267 dbfn_close(open_db *dbblock)
 268 {
 269 EXIM_DBCLOSE(dbblock->dbptr);
 270 (void)close(dbblock->lockfd);
 271 DEBUG(D_hints_lookup)
 272   { debug_printf_indent("closed hints database and lockfile\n"); acl_level--; }
 273 }
 274
 275
 276
 277
 278 /*************************************************
 279 *             Read from database file            *
 280 *************************************************/
 281
 282 /* Passing back the pointer unchanged is useless, because there is
 283 no guarantee of alignment. Since all the records used by Exim need
 284 to be properly aligned to pick out the timestamps, etc., we might as
 285 well do the copying centrally here.
 286
 287 Most calls don't need the length, so there is a macro called dbfn_read which
 288 has two arguments; it calls this function adding NULL as the third.
 289
 290 Arguments:
 291   dbblock   a pointer to an open database block
 292   key       the key of the record to be read
 293   length    a pointer to an int into which to return the length, if not NULL
 294
 295 Returns: a pointer to the retrieved record, or
 296          NULL if the record is not found
 297 */
 298
 299 void *
 300 dbfn_read_with_length(open_db *dbblock, const uschar *key, int *length)
 301 {
 302 void *yield;
 303 EXIM_DATUM key_datum, result_datum;
 304 int klen = Ustrlen(key) + 1;
 305 uschar * key_copy = store_get(klen);
 306
 307 memcpy(key_copy, key, klen);
 308
 309 DEBUG(D_hints_lookup) debug_printf_indent("dbfn_read: key=%s\n", key);
 310
 311 EXIM_DATUM_INIT(key_datum);         /* Some DBM libraries require the datum */
 312 EXIM_DATUM_INIT(result_datum);      /* to be cleared before use. */
 313 EXIM_DATUM_DATA(key_datum) = CS key_copy;
 314 EXIM_DATUM_SIZE(key_datum) = klen;
 315
 316 if (!EXIM_DBGET(dbblock->dbptr, key_datum, result_datum)) return NULL;
 317
 318 yield = store_get(EXIM_DATUM_SIZE(result_datum));
 319 memcpy(yield, EXIM_DATUM_DATA(result_datum), EXIM_DATUM_SIZE(result_datum));
 320 if (length != NULL) *length = EXIM_DATUM_SIZE(result_datum);
 321
 322 EXIM_DATUM_FREE(result_datum);    /* Some DBM libs require freeing */
 323 return yield;
 324 }
 325
 326
 327
 328 /*************************************************
 329 *             Write to database file             *
 330 *************************************************/
 331
 332 /*
 333 Arguments:
 334   dbblock   a pointer to an open database block
 335   key       the key of the record to be written
 336   ptr       a pointer to the record to be written
 337   length    the length of the record to be written
 338
 339 Returns:    the yield of the underlying dbm or db "write" function. If this
 340             is dbm, the value is zero for OK.
 341 */
 342
 343 int
 344 dbfn_write(open_db *dbblock, const uschar *key, void *ptr, int length)
 345 {
 346 EXIM_DATUM key_datum, value_datum;
 347 dbdata_generic *gptr = (dbdata_generic *)ptr;
 348 int klen = Ustrlen(key) + 1;
 349 uschar * key_copy = store_get(klen);
 350
 351 memcpy(key_copy, key, klen);
 352 gptr->time_stamp = time(NULL);
 353
 354 DEBUG(D_hints_lookup) debug_printf_indent("dbfn_write: key=%s\n", key);
 355
 356 EXIM_DATUM_INIT(key_datum);         /* Some DBM libraries require the datum */
 357 EXIM_DATUM_INIT(value_datum);       /* to be cleared before use. */
 358 EXIM_DATUM_DATA(key_datum) = CS key_copy;
 359 EXIM_DATUM_SIZE(key_datum) = klen;
 360 EXIM_DATUM_DATA(value_datum) = CS ptr;
 361 EXIM_DATUM_SIZE(value_datum) = length;
 362 return EXIM_DBPUT(dbblock->dbptr, key_datum, value_datum);
 363 }
 364
 365
 366
 367 /*************************************************
 368 *           Delete record from database file     *
 369 *************************************************/
 370
 371 /*
 372 Arguments:
 373   dbblock    a pointer to an open database block
 374   key        the key of the record to be deleted
 375
 376 Returns: the yield of the underlying dbm or db "delete" function.
 377 */
 378
 379 int
 380 dbfn_delete(open_db *dbblock, const uschar *key)
 381 {
 382 int klen = Ustrlen(key) + 1;
 383 uschar * key_copy = store_get(klen);
 384
 385 memcpy(key_copy, key, klen);
 386 EXIM_DATUM key_datum;
 387 EXIM_DATUM_INIT(key_datum);         /* Some DBM libraries require clearing */
 388 EXIM_DATUM_DATA(key_datum) = CS key_copy;
 389 EXIM_DATUM_SIZE(key_datum) = klen;
 390 return EXIM_DBDEL(dbblock->dbptr, key_datum);
 391 }
 392
 393
 394
 395 /*************************************************
 396 *         Scan the keys of a database file       *
 397 *************************************************/
 398
 399 /*
 400 Arguments:
 401   dbblock  a pointer to an open database block
 402   start    TRUE if starting a new scan
 403            FALSE if continuing with the current scan
 404   cursor   a pointer to a pointer to a cursor anchor, for those dbm libraries
 405            that use the notion of a cursor
 406
 407 Returns:   the next record from the file, or
 408            NULL if there are no more
 409 */
 410
 411 uschar *
 412 dbfn_scan(open_db *dbblock, BOOL start, EXIM_CURSOR **cursor)
 413 {
 414 EXIM_DATUM key_datum, value_datum;
 415 uschar *yield;
 416 value_datum = value_datum;    /* dummy; not all db libraries use this */
 417
 418 /* Some dbm require an initialization */
 419
 420 if (start) EXIM_DBCREATE_CURSOR(dbblock->dbptr, cursor);
 421
 422 EXIM_DATUM_INIT(key_datum);         /* Some DBM libraries require the datum */
 423 EXIM_DATUM_INIT(value_datum);       /* to be cleared before use. */
 424
 425 yield = (EXIM_DBSCAN(dbblock->dbptr, key_datum, value_datum, start, *cursor))?
 426   US EXIM_DATUM_DATA(key_datum) : NULL;
 427
 428 /* Some dbm require a termination */
 429
 430 if (!yield) EXIM_DBDELETE_CURSOR(*cursor);
 431 return yield;
 432 }
 433
 434
 435
 436 /*************************************************
 437 **************************************************
 438 *             Stand-alone test program           *
 439 **************************************************
 440 *************************************************/
 441
 442 #ifdef STAND_ALONE
 443
 444 int
 445 main(int argc, char **cargv)
 446 {
 447 open_db dbblock[8];
 448 int max_db = sizeof(dbblock)/sizeof(open_db);
 449 int current = -1;
 450 int showtime = 0;
 451 int i;
 452 dbdata_wait *dbwait = NULL;
 453 uschar **argv = USS cargv;
 454 uschar buffer[256];
 455 uschar structbuffer[1024];
 456
 457 if (argc != 2)
 458   {
 459   printf("Usage: test_dbfn directory\n");
 460   printf("The subdirectory called \"db\" in the given directory is used for\n");
 461   printf("the files used in this test program.\n");
 462   return 1;
 463   }
 464
 465 /* Initialize */
 466
 467 spool_directory = argv[1];
 468 debug_selector = D_all - D_memory;
 469 debug_file = stderr;
 470 big_buffer = malloc(big_buffer_size);
 471
 472 for (i = 0; i < max_db; i++) dbblock[i].dbptr = NULL;
 473
 474 printf("\nExim's db functions tester: interface type is %s\n", EXIM_DBTYPE);
 475 printf("DBM library: ");
 476
 477 #ifdef DB_VERSION_STRING
 478 printf("Berkeley DB: %s\n", DB_VERSION_STRING);
 479 #elif defined(BTREEVERSION) && defined(HASHVERSION)
 480   #ifdef USE_DB
 481   printf("probably Berkeley DB version 1.8x (native mode)\n");
 482   #else
 483   printf("probably Berkeley DB version 1.8x (compatibility mode)\n");
 484   #endif
 485 #elif defined(_DBM_RDONLY) || defined(dbm_dirfno)
 486 printf("probably ndbm\n");
 487 #elif defined(USE_TDB)
 488 printf("using tdb\n");
 489 #else
 490   #ifdef USE_GDBM
 491   printf("probably GDBM (native mode)\n");
 492   #else
 493   printf("probably GDBM (compatibility mode)\n");
 494   #endif
 495 #endif
 496
 497 /* Test the functions */
 498
 499 printf("\nTest the functions\n> ");
 500
 501 while (Ufgets(buffer, 256, stdin) != NULL)
 502   {
 503   int len = Ustrlen(buffer);
 504   int count = 1;
 505   clock_t start = 1;
 506   clock_t stop = 0;
 507   uschar *cmd = buffer;
 508   while (len > 0 && isspace((uschar)buffer[len-1])) len--;
 509   buffer[len] = 0;
 510
 511   if (isdigit((uschar)*cmd))
 512     {
 513     count = Uatoi(cmd);
 514     while (isdigit((uschar)*cmd)) cmd++;
 515     while (isspace((uschar)*cmd)) cmd++;
 516     }
 517
 518   if (Ustrncmp(cmd, "open", 4) == 0)
 519     {
 520     int i;
 521     open_db *odb;
 522     uschar *s = cmd + 4;
 523     while (isspace((uschar)*s)) s++;
 524
 525     for (i = 0; i < max_db; i++)
 526       if (dbblock[i].dbptr == NULL) break;
 527
 528     if (i >= max_db)
 529       {
 530       printf("Too many open databases\n> ");
 531       continue;
 532       }
 533
 534     start = clock();
 535     odb = dbfn_open(s, O_RDWR, dbblock + i, TRUE);
 536     stop = clock();
 537
 538     if (odb)
 539       {
 540       current = i;
 541       printf("opened %d\n", current);
 542       }
 543     /* Other error cases will have written messages */
 544     else if (errno == ENOENT)
 545       {
 546       printf("open failed: %s%s\n", strerror(errno),
 547         #ifdef USE_DB
 548         " (or other Berkeley DB error)"
 549         #else
 550         ""
 551         #endif
 552         );
 553       }
 554     }
 555
 556   else if (Ustrncmp(cmd, "write", 5) == 0)
 557     {
 558     int rc = 0;
 559     uschar *key = cmd + 5;
 560     uschar *data;
 561
 562     if (current < 0)
 563       {
 564       printf("No current database\n");
 565       continue;
 566       }
 567
 568     while (isspace((uschar)*key)) key++;
 569     data = key;
 570     while (*data != 0 && !isspace((uschar)*data)) data++;
 571     *data++ = 0;
 572     while (isspace((uschar)*data)) data++;
 573
 574     dbwait = (dbdata_wait *)(&structbuffer);
 575     Ustrcpy(dbwait->text, data);
 576
 577     start = clock();
 578     while (count-- > 0)
 579       rc = dbfn_write(dbblock + current, key, dbwait,
 580         Ustrlen(data) + sizeof(dbdata_wait));
 581     stop = clock();
 582     if (rc != 0) printf("Failed: %s\n", strerror(errno));
 583     }
 584
 585   else if (Ustrncmp(cmd, "read", 4) == 0)
 586     {
 587     uschar *key = cmd + 4;
 588     if (current < 0)
 589       {
 590       printf("No current database\n");
 591       continue;
 592       }
 593     while (isspace((uschar)*key)) key++;
 594     start = clock();
 595     while (count-- > 0)
 596       dbwait = (dbdata_wait *)dbfn_read_with_length(dbblock+ current, key, NULL);
 597     stop = clock();
 598     printf("%s\n", (dbwait == NULL)? "<not found>" : CS dbwait->text);
 599     }
 600
 601   else if (Ustrncmp(cmd, "delete", 6) == 0)
 602     {
 603     uschar *key = cmd + 6;
 604     if (current < 0)
 605       {
 606       printf("No current database\n");
 607       continue;
 608       }
 609     while (isspace((uschar)*key)) key++;
 610     dbfn_delete(dbblock + current, key);
 611     }
 612
 613   else if (Ustrncmp(cmd, "scan", 4) == 0)
 614     {
 615     EXIM_CURSOR *cursor;
 616     BOOL startflag = TRUE;
 617     uschar *key;
 618     uschar keybuffer[256];
 619     if (current < 0)
 620       {
 621       printf("No current database\n");
 622       continue;
 623       }
 624     start = clock();
 625     while ((key = dbfn_scan(dbblock + current, startflag, &cursor)) != NULL)
 626       {
 627       startflag = FALSE;
 628       Ustrcpy(keybuffer, key);
 629       dbwait = (dbdata_wait *)dbfn_read_with_length(dbblock + current,
 630         keybuffer, NULL);
 631       printf("%s: %s\n", keybuffer, dbwait->text);
 632       }
 633     stop = clock();
 634     printf("End of scan\n");
 635     }
 636
 637   else if (Ustrncmp(cmd, "close", 5) == 0)
 638     {
 639     uschar *s = cmd + 5;
 640     while (isspace((uschar)*s)) s++;
 641     i = Uatoi(s);
 642     if (i >= max_db || dbblock[i].dbptr == NULL) printf("Not open\n"); else
 643       {
 644       start = clock();
 645       dbfn_close(dbblock + i);
 646       stop = clock();
 647       dbblock[i].dbptr = NULL;
 648       if (i == current) current = -1;
 649       }
 650     }
 651
 652   else if (Ustrncmp(cmd, "file", 4) == 0)
 653     {
 654     uschar *s = cmd + 4;
 655     while (isspace((uschar)*s)) s++;
 656     i = Uatoi(s);
 657     if (i >= max_db || dbblock[i].dbptr == NULL) printf("Not open\n");
 658       else current = i;
 659     }
 660
 661   else if (Ustrncmp(cmd, "time", 4) == 0)
 662     {
 663     showtime = ~showtime;
 664     printf("Timing %s\n", showtime? "on" : "off");
 665     }
 666
 667   else if (Ustrcmp(cmd, "q") == 0 || Ustrncmp(cmd, "quit", 4) == 0) break;
 668
 669   else if (Ustrncmp(cmd, "help", 4) == 0)
 670     {
 671     printf("close  [<number>]              close file [<number>]\n");
 672     printf("delete <key>                   remove record from current file\n");
 673     printf("file   <number>                make file <number> current\n");
 674     printf("open   <name>                  open db file\n");
 675     printf("q[uit]                         exit program\n");
 676     printf("read   <key>                   read record from current file\n");
 677     printf("scan                           scan current file\n");
 678     printf("time                           time display on/off\n");
 679     printf("write  <key> <rest-of-line>    write record to current file\n");
 680     }
 681
 682   else printf("Eh?\n");
 683
 684   if (showtime && stop >= start)
 685     printf("start=%d stop=%d difference=%d\n", (int)start, (int)stop,
 686      (int)(stop - start));
 687
 688   printf("> ");
 689   }
 690
 691 for (i = 0; i < max_db; i++)
 692   {
 693   if (dbblock[i].dbptr != NULL)
 694     {
 695     printf("\nClosing %d", i);
 696     dbfn_close(dbblock + i);
 697     }
 698   }
 699
 700 printf("\n");
 701 return 0;
 702 }
 703
 704 #endif
 705
 706 /* End of dbfn.c */