src/src/dbfn.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2015 */
   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 buffer[256];
  95
  96 /* The first thing to do is to open a separate file on which to lock. This
  97 ensures that Exim has exclusive use of the database before it even tries to
  98 open it. Early versions tried to lock on the open database itself, but that
  99 gave rise to mysterious problems from time to time - it was suspected that some
 100 DB libraries "do things" on their open() calls which break the interlocking.
 101 The lock file is never written to, but we open it for writing so we can get a
 102 write lock if required. If it does not exist, we create it. This is done
 103 separately so we know when we have done it, because when running as root we
 104 need to change the ownership - see the bottom of this function. We also try to
 105 make the directory as well, just in case. We won't be doing this many times
 106 unnecessarily, because usually the lock file will be there. If the directory
 107 exists, there is no error. */
 108
 109 sprintf(CS buffer, "%s/db/%s.lockfile", spool_directory, name);
 110
 111 if ((dbblock->lockfd = Uopen(buffer, O_RDWR, EXIMDB_LOCKFILE_MODE)) < 0)
 112   {
 113   created = TRUE;
 114   (void)directory_make(spool_directory, US"db", EXIMDB_DIRECTORY_MODE, TRUE);
 115   dbblock->lockfd = Uopen(buffer, O_RDWR|O_CREAT, EXIMDB_LOCKFILE_MODE);
 116   }
 117
 118 if (dbblock->lockfd < 0)
 119   {
 120   log_write(0, LOG_MAIN, "%s",
 121     string_open_failed(errno, "database lock file %s", buffer));
 122   errno = 0;      /* Indicates locking failure */
 123   return NULL;
 124   }
 125
 126 /* Now we must get a lock on the opened lock file; do this with a blocking
 127 lock that times out. */
 128
 129 lock_data.l_type = read_only? F_RDLCK : F_WRLCK;
 130 lock_data.l_whence = lock_data.l_start = lock_data.l_len = 0;
 131
 132 DEBUG(D_hints_lookup|D_retry|D_route|D_deliver)
 133   debug_printf("locking %s\n", buffer);
 134
 135 sigalrm_seen = FALSE;
 136 alarm(EXIMDB_LOCK_TIMEOUT);
 137 rc = fcntl(dbblock->lockfd, F_SETLKW, &lock_data);
 138 alarm(0);
 139
 140 if (sigalrm_seen) errno = ETIMEDOUT;
 141 if (rc < 0)
 142   {
 143   log_write(0, LOG_MAIN|LOG_PANIC, "Failed to get %s lock for %s: %s",
 144     read_only? "read" : "write", buffer,
 145     (errno == ETIMEDOUT)? "timed out" : strerror(errno));
 146   (void)close(dbblock->lockfd);
 147   errno = 0;       /* Indicates locking failure */
 148   return NULL;
 149   }
 150
 151 DEBUG(D_hints_lookup) debug_printf("locked %s\n", buffer);
 152
 153 /* At this point we have an opened and locked separate lock file, that is,
 154 exclusive access to the database, so we can go ahead and open it. If we are
 155 expected to create it, don't do so at first, again so that we can detect
 156 whether we need to change its ownership (see comments about the lock file
 157 above.) There have been regular reports of crashes while opening hints
 158 databases - often this is caused by non-matching db.h and the library. To make
 159 it easy to pin this down, there are now debug statements on either side of the
 160 open call. */
 161
 162 sprintf(CS buffer, "%s/db/%s", spool_directory, name);
 163 DEBUG(D_hints_lookup) debug_printf("EXIM_DBOPEN(%s)\n", buffer);
 164 EXIM_DBOPEN(buffer, flags, EXIMDB_MODE, &(dbblock->dbptr));
 165 DEBUG(D_hints_lookup) debug_printf("returned from EXIM_DBOPEN\n");
 166
 167 if (dbblock->dbptr == NULL && errno == ENOENT && flags == O_RDWR)
 168   {
 169   DEBUG(D_hints_lookup)
 170     debug_printf("%s appears not to exist: trying to create\n", buffer);
 171   created = TRUE;
 172   EXIM_DBOPEN(buffer, flags|O_CREAT, EXIMDB_MODE, &(dbblock->dbptr));
 173   DEBUG(D_hints_lookup) debug_printf("returned from EXIM_DBOPEN\n");
 174   }
 175
 176 save_errno = errno;
 177
 178 /* If we are running as root and this is the first access to the database, its
 179 files will be owned by root. We want them to be owned by exim. We detect this
 180 situation by noting above when we had to create the lock file or the database
 181 itself. Because the different dbm libraries use different extensions for their
 182 files, I don't know of any easier way of arranging this than scanning the
 183 directory for files with the appropriate base name. At least this deals with
 184 the lock file at the same time. Also, the directory will typically have only
 185 half a dozen files, so the scan will be quick.
 186
 187 This code is placed here, before the test for successful opening, because there
 188 was a case when a file was created, but the DBM library still returned NULL
 189 because of some problem. It also sorts out the lock file if that was created
 190 but creation of the database file failed. */
 191
 192 if (created && geteuid() == root_uid)
 193   {
 194   DIR *dd;
 195   struct dirent *ent;
 196   uschar *lastname = Ustrrchr(buffer, '/') + 1;
 197   int namelen = Ustrlen(name);
 198
 199   *lastname = 0;
 200   dd = opendir(CS buffer);
 201
 202   while ((ent = readdir(dd)) != NULL)
 203     {
 204     if (Ustrncmp(ent->d_name, name, namelen) == 0)
 205       {
 206       struct stat statbuf;
 207       Ustrcpy(lastname, ent->d_name);
 208       if (Ustat(buffer, &statbuf) >= 0 && statbuf.st_uid != exim_uid)
 209         {
 210         DEBUG(D_hints_lookup) debug_printf("ensuring %s is owned by exim\n", buffer);
 211         if (Uchown(buffer, exim_uid, exim_gid))
 212           DEBUG(D_hints_lookup) debug_printf("failed setting %s to owned by exim\n", buffer);
 213         }
 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 not if the file just doesn't exist. */
 222
 223 if (dbblock->dbptr == NULL)
 224   {
 225   if (save_errno != ENOENT)
 226     {
 227     if (lof)
 228       log_write(0, LOG_MAIN, "%s", string_open_failed(save_errno, "DB file %s",
 229         buffer));
 230     else
 231       DEBUG(D_hints_lookup)
 232         debug_printf("%s", CS string_open_failed(save_errno, "DB file %s\n",
 233           buffer));
 234     }
 235   (void)close(dbblock->lockfd);
 236   errno = save_errno;
 237   return NULL;
 238   }
 239
 240 DEBUG(D_hints_lookup)
 241   debug_printf("opened hints database %s: flags=%s\n", buffer,
 242     (flags == O_RDONLY)? "O_RDONLY" : (flags == O_RDWR)? "O_RDWR" :
 243     (flags == (O_RDWR|O_CREAT))? "O_RDWR|O_CREAT" : "??");
 244
 245 /* Pass back the block containing the opened database handle and the open fd
 246 for the lock. */
 247
 248 return dbblock;
 249 }
 250
 251
 252
 253
 254 /*************************************************
 255 *         Unlock and close a database file       *
 256 *************************************************/
 257
 258 /* Closing a file automatically unlocks it, so after closing the database, just
 259 close the lock file.
 260
 261 Argument: a pointer to an open database block
 262 Returns:  nothing
 263 */
 264
 265 void
 266 dbfn_close(open_db *dbblock)
 267 {
 268 EXIM_DBCLOSE(dbblock->dbptr);
 269 (void)close(dbblock->lockfd);
 270 }
 271
 272
 273
 274
 275 /*************************************************
 276 *             Read from database file            *
 277 *************************************************/
 278
 279 /* Passing back the pointer unchanged is useless, because there is
 280 no guarantee of alignment. Since all the records used by Exim need
 281 to be properly aligned to pick out the timestamps, etc., we might as
 282 well do the copying centrally here.
 283
 284 Most calls don't need the length, so there is a macro called dbfn_read which
 285 has two arguments; it calls this function adding NULL as the third.
 286
 287 Arguments:
 288   dbblock   a pointer to an open database block
 289   key       the key of the record to be read
 290   length    a pointer to an int into which to return the length, if not NULL
 291
 292 Returns: a pointer to the retrieved record, or
 293          NULL if the record is not found
 294 */
 295
 296 void *
 297 dbfn_read_with_length(open_db *dbblock, const uschar *key, int *length)
 298 {
 299 void *yield;
 300 EXIM_DATUM key_datum, result_datum;
 301 int klen = Ustrlen(key) + 1;
 302 uschar * key_copy = store_get(klen);
 303
 304 memcpy(key_copy, key, klen);
 305
 306 DEBUG(D_hints_lookup) debug_printf("dbfn_read: key=%s\n", key);
 307
 308 EXIM_DATUM_INIT(key_datum);         /* Some DBM libraries require the datum */
 309 EXIM_DATUM_INIT(result_datum);      /* to be cleared before use. */
 310 EXIM_DATUM_DATA(key_datum) = CS key_copy;
 311 EXIM_DATUM_SIZE(key_datum) = klen;
 312
 313 if (!EXIM_DBGET(dbblock->dbptr, key_datum, result_datum)) return NULL;
 314
 315 yield = store_get(EXIM_DATUM_SIZE(result_datum));
 316 memcpy(yield, EXIM_DATUM_DATA(result_datum), EXIM_DATUM_SIZE(result_datum));
 317 if (length != NULL) *length = EXIM_DATUM_SIZE(result_datum);
 318
 319 EXIM_DATUM_FREE(result_datum);    /* Some DBM libs require freeing */
 320 return yield;
 321 }
 322
 323
 324
 325 /*************************************************
 326 *             Write to database file             *
 327 *************************************************/
 328
 329 /*
 330 Arguments:
 331   dbblock   a pointer to an open database block
 332   key       the key of the record to be written
 333   ptr       a pointer to the record to be written
 334   length    the length of the record to be written
 335
 336 Returns:    the yield of the underlying dbm or db "write" function. If this
 337             is dbm, the value is zero for OK.
 338 */
 339
 340 int
 341 dbfn_write(open_db *dbblock, const uschar *key, void *ptr, int length)
 342 {
 343 EXIM_DATUM key_datum, value_datum;
 344 dbdata_generic *gptr = (dbdata_generic *)ptr;
 345 int klen = Ustrlen(key) + 1;
 346 uschar * key_copy = store_get(klen);
 347
 348 memcpy(key_copy, key, klen);
 349 gptr->time_stamp = time(NULL);
 350
 351 DEBUG(D_hints_lookup) debug_printf("dbfn_write: key=%s\n", key);
 352
 353 EXIM_DATUM_INIT(key_datum);         /* Some DBM libraries require the datum */
 354 EXIM_DATUM_INIT(value_datum);       /* to be cleared before use. */
 355 EXIM_DATUM_DATA(key_datum) = CS key_copy;
 356 EXIM_DATUM_SIZE(key_datum) = klen;
 357 EXIM_DATUM_DATA(value_datum) = CS ptr;
 358 EXIM_DATUM_SIZE(value_datum) = length;
 359 return EXIM_DBPUT(dbblock->dbptr, key_datum, value_datum);
 360 }
 361
 362
 363
 364 /*************************************************
 365 *           Delete record from database file     *
 366 *************************************************/
 367
 368 /*
 369 Arguments:
 370   dbblock    a pointer to an open database block
 371   key        the key of the record to be deleted
 372
 373 Returns: the yield of the underlying dbm or db "delete" function.
 374 */
 375
 376 int
 377 dbfn_delete(open_db *dbblock, const uschar *key)
 378 {
 379 int klen = Ustrlen(key) + 1;
 380 uschar * key_copy = store_get(klen);
 381
 382 memcpy(key_copy, key, klen);
 383 EXIM_DATUM key_datum;
 384 EXIM_DATUM_INIT(key_datum);         /* Some DBM libraries require clearing */
 385 EXIM_DATUM_DATA(key_datum) = CS key_copy;
 386 EXIM_DATUM_SIZE(key_datum) = klen;
 387 return EXIM_DBDEL(dbblock->dbptr, key_datum);
 388 }
 389
 390
 391
 392 /*************************************************
 393 *         Scan the keys of a database file       *
 394 *************************************************/
 395
 396 /*
 397 Arguments:
 398   dbblock  a pointer to an open database block
 399   start    TRUE if starting a new scan
 400            FALSE if continuing with the current scan
 401   cursor   a pointer to a pointer to a cursor anchor, for those dbm libraries
 402            that use the notion of a cursor
 403
 404 Returns:   the next record from the file, or
 405            NULL if there are no more
 406 */
 407
 408 uschar *
 409 dbfn_scan(open_db *dbblock, BOOL start, EXIM_CURSOR **cursor)
 410 {
 411 EXIM_DATUM key_datum, value_datum;
 412 uschar *yield;
 413 value_datum = value_datum;    /* dummy; not all db libraries use this */
 414
 415 /* Some dbm require an initialization */
 416
 417 if (start) EXIM_DBCREATE_CURSOR(dbblock->dbptr, cursor);
 418
 419 EXIM_DATUM_INIT(key_datum);         /* Some DBM libraries require the datum */
 420 EXIM_DATUM_INIT(value_datum);       /* to be cleared before use. */
 421
 422 yield = (EXIM_DBSCAN(dbblock->dbptr, key_datum, value_datum, start, *cursor))?
 423   US EXIM_DATUM_DATA(key_datum) : NULL;
 424
 425 /* Some dbm require a termination */
 426
 427 if (!yield) EXIM_DBDELETE_CURSOR(*cursor);
 428 return yield;
 429 }
 430
 431
 432
 433 /*************************************************
 434 **************************************************
 435 *             Stand-alone test program           *
 436 **************************************************
 437 *************************************************/
 438
 439 #ifdef STAND_ALONE
 440
 441 int
 442 main(int argc, char **cargv)
 443 {
 444 open_db dbblock[8];
 445 int max_db = sizeof(dbblock)/sizeof(open_db);
 446 int current = -1;
 447 int showtime = 0;
 448 int i;
 449 dbdata_wait *dbwait = NULL;
 450 uschar **argv = USS cargv;
 451 uschar buffer[256];
 452 uschar structbuffer[1024];
 453
 454 if (argc != 2)
 455   {
 456   printf("Usage: test_dbfn directory\n");
 457   printf("The subdirectory called \"db\" in the given directory is used for\n");
 458   printf("the files used in this test program.\n");
 459   return 1;
 460   }
 461
 462 /* Initialize */
 463
 464 spool_directory = argv[1];
 465 debug_selector = D_all - D_memory;
 466 debug_file = stderr;
 467 big_buffer = malloc(big_buffer_size);
 468
 469 for (i = 0; i < max_db; i++) dbblock[i].dbptr = NULL;
 470
 471 printf("\nExim's db functions tester: interface type is %s\n", EXIM_DBTYPE);
 472 printf("DBM library: ");
 473
 474 #ifdef DB_VERSION_STRING
 475 printf("Berkeley DB: %s\n", DB_VERSION_STRING);
 476 #elif defined(BTREEVERSION) && defined(HASHVERSION)
 477   #ifdef USE_DB
 478   printf("probably Berkeley DB version 1.8x (native mode)\n");
 479   #else
 480   printf("probably Berkeley DB version 1.8x (compatibility mode)\n");
 481   #endif
 482 #elif defined(_DBM_RDONLY) || defined(dbm_dirfno)
 483 printf("probably ndbm\n");
 484 #elif defined(USE_TDB)
 485 printf("using tdb\n");
 486 #else
 487   #ifdef USE_GDBM
 488   printf("probably GDBM (native mode)\n");
 489   #else
 490   printf("probably GDBM (compatibility mode)\n");
 491   #endif
 492 #endif
 493
 494 /* Test the functions */
 495
 496 printf("\nTest the functions\n> ");
 497
 498 while (Ufgets(buffer, 256, stdin) != NULL)
 499   {
 500   int len = Ustrlen(buffer);
 501   int count = 1;
 502   clock_t start = 1;
 503   clock_t stop = 0;
 504   uschar *cmd = buffer;
 505   while (len > 0 && isspace((uschar)buffer[len-1])) len--;
 506   buffer[len] = 0;
 507
 508   if (isdigit((uschar)*cmd))
 509     {
 510     count = Uatoi(cmd);
 511     while (isdigit((uschar)*cmd)) cmd++;
 512     while (isspace((uschar)*cmd)) cmd++;
 513     }
 514
 515   if (Ustrncmp(cmd, "open", 4) == 0)
 516     {
 517     int i;
 518     open_db *odb;
 519     uschar *s = cmd + 4;
 520     while (isspace((uschar)*s)) s++;
 521
 522     for (i = 0; i < max_db; i++)
 523       if (dbblock[i].dbptr == NULL) break;
 524
 525     if (i >= max_db)
 526       {
 527       printf("Too many open databases\n> ");
 528       continue;
 529       }
 530
 531     start = clock();
 532     odb = dbfn_open(s, O_RDWR, dbblock + i, TRUE);
 533     stop = clock();
 534
 535     if (odb != NULL)
 536       {
 537       current = i;
 538       printf("opened %d\n", current);
 539       }
 540     /* Other error cases will have written messages */
 541     else if (errno == ENOENT)
 542       {
 543       printf("open failed: %s%s\n", strerror(errno),
 544         #ifdef USE_DB
 545         " (or other Berkeley DB error)"
 546         #else
 547         ""
 548         #endif
 549         );
 550       }
 551     }
 552
 553   else if (Ustrncmp(cmd, "write", 5) == 0)
 554     {
 555     int rc = 0;
 556     uschar *key = cmd + 5;
 557     uschar *data;
 558
 559     if (current < 0)
 560       {
 561       printf("No current database\n");
 562       continue;
 563       }
 564
 565     while (isspace((uschar)*key)) key++;
 566     data = key;
 567     while (*data != 0 && !isspace((uschar)*data)) data++;
 568     *data++ = 0;
 569     while (isspace((uschar)*data)) data++;
 570
 571     dbwait = (dbdata_wait *)(&structbuffer);
 572     Ustrcpy(dbwait->text, data);
 573
 574     start = clock();
 575     while (count-- > 0)
 576       rc = dbfn_write(dbblock + current, key, dbwait,
 577         Ustrlen(data) + sizeof(dbdata_wait));
 578     stop = clock();
 579     if (rc != 0) printf("Failed: %s\n", strerror(errno));
 580     }
 581
 582   else if (Ustrncmp(cmd, "read", 4) == 0)
 583     {
 584     uschar *key = cmd + 4;
 585     if (current < 0)
 586       {
 587       printf("No current database\n");
 588       continue;
 589       }
 590     while (isspace((uschar)*key)) key++;
 591     start = clock();
 592     while (count-- > 0)
 593       dbwait = (dbdata_wait *)dbfn_read_with_length(dbblock+ current, key, NULL);
 594     stop = clock();
 595     printf("%s\n", (dbwait == NULL)? "<not found>" : CS dbwait->text);
 596     }
 597
 598   else if (Ustrncmp(cmd, "delete", 6) == 0)
 599     {
 600     uschar *key = cmd + 6;
 601     if (current < 0)
 602       {
 603       printf("No current database\n");
 604       continue;
 605       }
 606     while (isspace((uschar)*key)) key++;
 607     dbfn_delete(dbblock + current, key);
 608     }
 609
 610   else if (Ustrncmp(cmd, "scan", 4) == 0)
 611     {
 612     EXIM_CURSOR *cursor;
 613     BOOL startflag = TRUE;
 614     uschar *key;
 615     uschar keybuffer[256];
 616     if (current < 0)
 617       {
 618       printf("No current database\n");
 619       continue;
 620       }
 621     start = clock();
 622     while ((key = dbfn_scan(dbblock + current, startflag, &cursor)) != NULL)
 623       {
 624       startflag = FALSE;
 625       Ustrcpy(keybuffer, key);
 626       dbwait = (dbdata_wait *)dbfn_read_with_length(dbblock + current,
 627         keybuffer, NULL);
 628       printf("%s: %s\n", keybuffer, dbwait->text);
 629       }
 630     stop = clock();
 631     printf("End of scan\n");
 632     }
 633
 634   else if (Ustrncmp(cmd, "close", 5) == 0)
 635     {
 636     uschar *s = cmd + 5;
 637     while (isspace((uschar)*s)) s++;
 638     i = Uatoi(s);
 639     if (i >= max_db || dbblock[i].dbptr == NULL) printf("Not open\n"); else
 640       {
 641       start = clock();
 642       dbfn_close(dbblock + i);
 643       stop = clock();
 644       dbblock[i].dbptr = NULL;
 645       if (i == current) current = -1;
 646       }
 647     }
 648
 649   else if (Ustrncmp(cmd, "file", 4) == 0)
 650     {
 651     uschar *s = cmd + 4;
 652     while (isspace((uschar)*s)) s++;
 653     i = Uatoi(s);
 654     if (i >= max_db || dbblock[i].dbptr == NULL) printf("Not open\n");
 655       else current = i;
 656     }
 657
 658   else if (Ustrncmp(cmd, "time", 4) == 0)
 659     {
 660     showtime = ~showtime;
 661     printf("Timing %s\n", showtime? "on" : "off");
 662     }
 663
 664   else if (Ustrcmp(cmd, "q") == 0 || Ustrncmp(cmd, "quit", 4) == 0) break;
 665
 666   else if (Ustrncmp(cmd, "help", 4) == 0)
 667     {
 668     printf("close  [<number>]              close file [<number>]\n");
 669     printf("delete <key>                   remove record from current file\n");
 670     printf("file   <number>                make file <number> current\n");
 671     printf("open   <name>                  open db file\n");
 672     printf("q[uit]                         exit program\n");
 673     printf("read   <key>                   read record from current file\n");
 674     printf("scan                           scan current file\n");
 675     printf("time                           time display on/off\n");
 676     printf("write  <key> <rest-of-line>    write record to current file\n");
 677     }
 678
 679   else printf("Eh?\n");
 680
 681   if (showtime && stop >= start)
 682     printf("start=%d stop=%d difference=%d\n", (int)start, (int)stop,
 683      (int)(stop - start));
 684
 685   printf("> ");
 686   }
 687
 688 for (i = 0; i < max_db; i++)
 689   {
 690   if (dbblock[i].dbptr != NULL)
 691     {
 692     printf("\nClosing %d", i);
 693     dbfn_close(dbblock + i);
 694     }
 695   }
 696
 697 printf("\n");
 698 return 0;
 699 }
 700
 701 #endif
 702
 703 /* End of dbfn.c */