1 /*
2 * psql - the PostgreSQL interactive terminal
3 *
4 * Copyright (c) 2000-2021, PostgreSQL Global Development Group
5 *
6 * src/bin/psql/common.c
7 */
8 #include "postgres_fe.h"
9
10 #include <ctype.h>
11 #include <limits.h>
12 #include <math.h>
13 #include <signal.h>
14 #ifndef WIN32
15 #include <unistd.h> /* for write() */
16 #else
17 #include <io.h> /* for _write() */
18 #include <win32.h>
19 #endif
20
21 #include "command.h"
22 #include "common.h"
23 #include "common/logging.h"
24 #include "copy.h"
25 #include "crosstabview.h"
26 #include "fe_utils/cancel.h"
27 #include "fe_utils/mbprint.h"
28 #include "fe_utils/string_utils.h"
29 #include "portability/instr_time.h"
30 #include "settings.h"
31
32 static bool DescribeQuery(const char *query, double *elapsed_msec);
33 static bool ExecQueryUsingCursor(const char *query, double *elapsed_msec);
34 static bool command_no_begin(const char *query);
35 static bool is_select_command(const char *query);
36
37
38 /*
39 * openQueryOutputFile --- attempt to open a query output file
40 *
41 * fname == NULL selects stdout, else an initial '|' selects a pipe,
42 * else plain file.
43 *
44 * Returns output file pointer into *fout, and is-a-pipe flag into *is_pipe.
45 * Caller is responsible for adjusting SIGPIPE state if it's a pipe.
46 *
47 * On error, reports suitable error message and returns false.
48 */
49 bool
openQueryOutputFile(const char * fname,FILE ** fout,bool * is_pipe)50 openQueryOutputFile(const char *fname, FILE **fout, bool *is_pipe)
51 {
52 if (!fname || fname[0] == '\0')
53 {
54 *fout = stdout;
55 *is_pipe = false;
56 }
57 else if (*fname == '|')
58 {
59 *fout = popen(fname + 1, "w");
60 *is_pipe = true;
61 }
62 else
63 {
64 *fout = fopen(fname, "w");
65 *is_pipe = false;
66 }
67
68 if (*fout == NULL)
69 {
70 pg_log_error("%s: %m", fname);
71 return false;
72 }
73
74 return true;
75 }
76
77 /*
78 * setQFout
79 * -- handler for -o command line option and \o command
80 *
81 * On success, updates pset with the new output file and returns true.
82 * On failure, returns false without changing pset state.
83 */
84 bool
setQFout(const char * fname)85 setQFout(const char *fname)
86 {
87 FILE *fout;
88 bool is_pipe;
89
90 /* First make sure we can open the new output file/pipe */
91 if (!openQueryOutputFile(fname, &fout, &is_pipe))
92 return false;
93
94 /* Close old file/pipe */
95 if (pset.queryFout && pset.queryFout != stdout && pset.queryFout != stderr)
96 {
97 if (pset.queryFoutPipe)
98 pclose(pset.queryFout);
99 else
100 fclose(pset.queryFout);
101 }
102
103 pset.queryFout = fout;
104 pset.queryFoutPipe = is_pipe;
105
106 /* Adjust SIGPIPE handling appropriately: ignore signal if is_pipe */
107 set_sigpipe_trap_state(is_pipe);
108 restore_sigpipe_trap();
109
110 return true;
111 }
112
113
114 /*
115 * Variable-fetching callback for flex lexer
116 *
117 * If the specified variable exists, return its value as a string (malloc'd
118 * and expected to be freed by the caller); else return NULL.
119 *
120 * If "quote" isn't PQUOTE_PLAIN, then return the value suitably quoted and
121 * escaped for the specified quoting requirement. (Failure in escaping
122 * should lead to printing an error and returning NULL.)
123 *
124 * "passthrough" is the pointer previously given to psql_scan_set_passthrough.
125 * In psql, passthrough points to a ConditionalStack, which we check to
126 * determine whether variable expansion is allowed.
127 */
128 char *
psql_get_variable(const char * varname,PsqlScanQuoteType quote,void * passthrough)129 psql_get_variable(const char *varname, PsqlScanQuoteType quote,
130 void *passthrough)
131 {
132 char *result = NULL;
133 const char *value;
134
135 /* In an inactive \if branch, suppress all variable substitutions */
136 if (passthrough && !conditional_active((ConditionalStack) passthrough))
137 return NULL;
138
139 value = GetVariable(pset.vars, varname);
140 if (!value)
141 return NULL;
142
143 switch (quote)
144 {
145 case PQUOTE_PLAIN:
146 result = pg_strdup(value);
147 break;
148 case PQUOTE_SQL_LITERAL:
149 case PQUOTE_SQL_IDENT:
150 {
151 /*
152 * For these cases, we use libpq's quoting functions, which
153 * assume the string is in the connection's client encoding.
154 */
155 char *escaped_value;
156
157 if (!pset.db)
158 {
159 pg_log_error("cannot escape without active connection");
160 return NULL;
161 }
162
163 if (quote == PQUOTE_SQL_LITERAL)
164 escaped_value =
165 PQescapeLiteral(pset.db, value, strlen(value));
166 else
167 escaped_value =
168 PQescapeIdentifier(pset.db, value, strlen(value));
169
170 if (escaped_value == NULL)
171 {
172 const char *error = PQerrorMessage(pset.db);
173
174 pg_log_info("%s", error);
175 return NULL;
176 }
177
178 /*
179 * Rather than complicate the lexer's API with a notion of
180 * which free() routine to use, just pay the price of an extra
181 * strdup().
182 */
183 result = pg_strdup(escaped_value);
184 PQfreemem(escaped_value);
185 break;
186 }
187 case PQUOTE_SHELL_ARG:
188 {
189 /*
190 * For this we use appendShellStringNoError, which is
191 * encoding-agnostic, which is fine since the shell probably
192 * is too. In any case, the only special character is "'",
193 * which is not known to appear in valid multibyte characters.
194 */
195 PQExpBufferData buf;
196
197 initPQExpBuffer(&buf);
198 if (!appendShellStringNoError(&buf, value))
199 {
200 pg_log_error("shell command argument contains a newline or carriage return: \"%s\"",
201 value);
202 free(buf.data);
203 return NULL;
204 }
205 result = buf.data;
206 break;
207 }
208
209 /* No default: we want a compiler warning for missing cases */
210 }
211
212 return result;
213 }
214
215
216 /*
217 * for backend Notice messages (INFO, WARNING, etc)
218 */
219 void
NoticeProcessor(void * arg,const char * message)220 NoticeProcessor(void *arg, const char *message)
221 {
222 (void) arg; /* not used */
223 pg_log_info("%s", message);
224 }
225
226
227
228 /*
229 * Code to support query cancellation
230 *
231 * Before we start a query, we enable the SIGINT signal catcher to send a
232 * cancel request to the backend.
233 *
234 * SIGINT is supposed to abort all long-running psql operations, not only
235 * database queries. In most places, this is accomplished by checking
236 * cancel_pressed during long-running loops. However, that won't work when
237 * blocked on user input (in readline() or fgets()). In those places, we
238 * set sigint_interrupt_enabled true while blocked, instructing the signal
239 * catcher to longjmp through sigint_interrupt_jmp. We assume readline and
240 * fgets are coded to handle possible interruption.
241 *
242 * On Windows, currently this does not work, so control-C is less useful
243 * there.
244 */
245 volatile bool sigint_interrupt_enabled = false;
246
247 sigjmp_buf sigint_interrupt_jmp;
248
249 static void
psql_cancel_callback(void)250 psql_cancel_callback(void)
251 {
252 #ifndef WIN32
253 /* if we are waiting for input, longjmp out of it */
254 if (sigint_interrupt_enabled)
255 {
256 sigint_interrupt_enabled = false;
257 siglongjmp(sigint_interrupt_jmp, 1);
258 }
259 #endif
260
261 /* else, set cancel flag to stop any long-running loops */
262 cancel_pressed = true;
263 }
264
265 void
psql_setup_cancel_handler(void)266 psql_setup_cancel_handler(void)
267 {
268 setup_cancel_handler(psql_cancel_callback);
269 }
270
271
272 /* ConnectionUp
273 *
274 * Returns whether our backend connection is still there.
275 */
276 static bool
ConnectionUp(void)277 ConnectionUp(void)
278 {
279 return PQstatus(pset.db) != CONNECTION_BAD;
280 }
281
282
283
284 /* CheckConnection
285 *
286 * Verify that we still have a good connection to the backend, and if not,
287 * see if it can be restored.
288 *
289 * Returns true if either the connection was still there, or it could be
290 * restored successfully; false otherwise. If, however, there was no
291 * connection and the session is non-interactive, this will exit the program
292 * with a code of EXIT_BADCONN.
293 */
294 static bool
CheckConnection(void)295 CheckConnection(void)
296 {
297 bool OK;
298
299 OK = ConnectionUp();
300 if (!OK)
301 {
302 if (!pset.cur_cmd_interactive)
303 {
304 pg_log_fatal("connection to server was lost");
305 exit(EXIT_BADCONN);
306 }
307
308 fprintf(stderr, _("The connection to the server was lost. Attempting reset: "));
309 PQreset(pset.db);
310 OK = ConnectionUp();
311 if (!OK)
312 {
313 fprintf(stderr, _("Failed.\n"));
314
315 /*
316 * Transition to having no connection; but stash away the failed
317 * connection so that we can still refer to its parameters in a
318 * later \connect attempt. Keep the state cleanup here in sync
319 * with do_connect().
320 */
321 if (pset.dead_conn)
322 PQfinish(pset.dead_conn);
323 pset.dead_conn = pset.db;
324 pset.db = NULL;
325 ResetCancelConn();
326 UnsyncVariables();
327 }
328 else
329 {
330 fprintf(stderr, _("Succeeded.\n"));
331
332 /*
333 * Re-sync, just in case anything changed. Keep this in sync with
334 * do_connect().
335 */
336 SyncVariables();
337 connection_warnings(false); /* Must be after SyncVariables */
338 }
339 }
340
341 return OK;
342 }
343
344
345
346
347 /*
348 * AcceptResult
349 *
350 * Checks whether a result is valid, giving an error message if necessary;
351 * and ensures that the connection to the backend is still up.
352 *
353 * Returns true for valid result, false for error state.
354 */
355 static bool
AcceptResult(const PGresult * result)356 AcceptResult(const PGresult *result)
357 {
358 bool OK;
359
360 if (!result)
361 OK = false;
362 else
363 switch (PQresultStatus(result))
364 {
365 case PGRES_COMMAND_OK:
366 case PGRES_TUPLES_OK:
367 case PGRES_EMPTY_QUERY:
368 case PGRES_COPY_IN:
369 case PGRES_COPY_OUT:
370 /* Fine, do nothing */
371 OK = true;
372 break;
373
374 case PGRES_BAD_RESPONSE:
375 case PGRES_NONFATAL_ERROR:
376 case PGRES_FATAL_ERROR:
377 OK = false;
378 break;
379
380 default:
381 OK = false;
382 pg_log_error("unexpected PQresultStatus: %d",
383 PQresultStatus(result));
384 break;
385 }
386
387 if (!OK)
388 {
389 const char *error = PQerrorMessage(pset.db);
390
391 if (strlen(error))
392 pg_log_info("%s", error);
393
394 CheckConnection();
395 }
396
397 return OK;
398 }
399
400
401 /*
402 * Set special variables from a query result
403 * - ERROR: true/false, whether an error occurred on this query
404 * - SQLSTATE: code of error, or "00000" if no error, or "" if unknown
405 * - ROW_COUNT: how many rows were returned or affected, or "0"
406 * - LAST_ERROR_SQLSTATE: same for last error
407 * - LAST_ERROR_MESSAGE: message of last error
408 *
409 * Note: current policy is to apply this only to the results of queries
410 * entered by the user, not queries generated by slash commands.
411 */
412 static void
SetResultVariables(PGresult * results,bool success)413 SetResultVariables(PGresult *results, bool success)
414 {
415 if (success)
416 {
417 const char *ntuples = PQcmdTuples(results);
418
419 SetVariable(pset.vars, "ERROR", "false");
420 SetVariable(pset.vars, "SQLSTATE", "00000");
421 SetVariable(pset.vars, "ROW_COUNT", *ntuples ? ntuples : "0");
422 }
423 else
424 {
425 const char *code = PQresultErrorField(results, PG_DIAG_SQLSTATE);
426 const char *mesg = PQresultErrorField(results, PG_DIAG_MESSAGE_PRIMARY);
427
428 SetVariable(pset.vars, "ERROR", "true");
429
430 /*
431 * If there is no SQLSTATE code, use an empty string. This can happen
432 * for libpq-detected errors (e.g., lost connection, ENOMEM).
433 */
434 if (code == NULL)
435 code = "";
436 SetVariable(pset.vars, "SQLSTATE", code);
437 SetVariable(pset.vars, "ROW_COUNT", "0");
438 SetVariable(pset.vars, "LAST_ERROR_SQLSTATE", code);
439 SetVariable(pset.vars, "LAST_ERROR_MESSAGE", mesg ? mesg : "");
440 }
441 }
442
443
444 /*
445 * ClearOrSaveResult
446 *
447 * If the result represents an error, remember it for possible display by
448 * \errverbose. Otherwise, just PQclear() it.
449 *
450 * Note: current policy is to apply this to the results of all queries,
451 * including "back door" queries, for debugging's sake. It's OK to use
452 * PQclear() directly on results known to not be error results, however.
453 */
454 static void
ClearOrSaveResult(PGresult * result)455 ClearOrSaveResult(PGresult *result)
456 {
457 if (result)
458 {
459 switch (PQresultStatus(result))
460 {
461 case PGRES_NONFATAL_ERROR:
462 case PGRES_FATAL_ERROR:
463 if (pset.last_error_result)
464 PQclear(pset.last_error_result);
465 pset.last_error_result = result;
466 break;
467
468 default:
469 PQclear(result);
470 break;
471 }
472 }
473 }
474
475
476 /*
477 * Print microtiming output. Always print raw milliseconds; if the interval
478 * is >= 1 second, also break it down into days/hours/minutes/seconds.
479 */
480 static void
PrintTiming(double elapsed_msec)481 PrintTiming(double elapsed_msec)
482 {
483 double seconds;
484 double minutes;
485 double hours;
486 double days;
487
488 if (elapsed_msec < 1000.0)
489 {
490 /* This is the traditional (pre-v10) output format */
491 printf(_("Time: %.3f ms\n"), elapsed_msec);
492 return;
493 }
494
495 /*
496 * Note: we could print just seconds, in a format like %06.3f, when the
497 * total is less than 1min. But that's hard to interpret unless we tack
498 * on "s" or otherwise annotate it. Forcing the display to include
499 * minutes seems like a better solution.
500 */
501 seconds = elapsed_msec / 1000.0;
502 minutes = floor(seconds / 60.0);
503 seconds -= 60.0 * minutes;
504 if (minutes < 60.0)
505 {
506 printf(_("Time: %.3f ms (%02d:%06.3f)\n"),
507 elapsed_msec, (int) minutes, seconds);
508 return;
509 }
510
511 hours = floor(minutes / 60.0);
512 minutes -= 60.0 * hours;
513 if (hours < 24.0)
514 {
515 printf(_("Time: %.3f ms (%02d:%02d:%06.3f)\n"),
516 elapsed_msec, (int) hours, (int) minutes, seconds);
517 return;
518 }
519
520 days = floor(hours / 24.0);
521 hours -= 24.0 * days;
522 printf(_("Time: %.3f ms (%.0f d %02d:%02d:%06.3f)\n"),
523 elapsed_msec, days, (int) hours, (int) minutes, seconds);
524 }
525
526
527 /*
528 * PSQLexec
529 *
530 * This is the way to send "backdoor" queries (those not directly entered
531 * by the user). It is subject to -E but not -e.
532 *
533 * Caller is responsible for handling the ensuing processing if a COPY
534 * command is sent.
535 *
536 * Note: we don't bother to check PQclientEncoding; it is assumed that no
537 * caller uses this path to issue "SET CLIENT_ENCODING".
538 */
539 PGresult *
PSQLexec(const char * query)540 PSQLexec(const char *query)
541 {
542 PGresult *res;
543
544 if (!pset.db)
545 {
546 pg_log_error("You are currently not connected to a database.");
547 return NULL;
548 }
549
550 if (pset.echo_hidden != PSQL_ECHO_HIDDEN_OFF)
551 {
552 printf(_("********* QUERY **********\n"
553 "%s\n"
554 "**************************\n\n"), query);
555 fflush(stdout);
556 if (pset.logfile)
557 {
558 fprintf(pset.logfile,
559 _("********* QUERY **********\n"
560 "%s\n"
561 "**************************\n\n"), query);
562 fflush(pset.logfile);
563 }
564
565 if (pset.echo_hidden == PSQL_ECHO_HIDDEN_NOEXEC)
566 return NULL;
567 }
568
569 SetCancelConn(pset.db);
570
571 res = PQexec(pset.db, query);
572
573 ResetCancelConn();
574
575 if (!AcceptResult(res))
576 {
577 ClearOrSaveResult(res);
578 res = NULL;
579 }
580
581 return res;
582 }
583
584
585 /*
586 * PSQLexecWatch
587 *
588 * This function is used for \watch command to send the query to
589 * the server and print out the results.
590 *
591 * Returns 1 if the query executed successfully, 0 if it cannot be repeated,
592 * e.g., because of the interrupt, -1 on error.
593 */
594 int
PSQLexecWatch(const char * query,const printQueryOpt * opt)595 PSQLexecWatch(const char *query, const printQueryOpt *opt)
596 {
597 PGresult *res;
598 double elapsed_msec = 0;
599 instr_time before;
600 instr_time after;
601
602 if (!pset.db)
603 {
604 pg_log_error("You are currently not connected to a database.");
605 return 0;
606 }
607
608 SetCancelConn(pset.db);
609
610 if (pset.timing)
611 INSTR_TIME_SET_CURRENT(before);
612
613 res = PQexec(pset.db, query);
614
615 ResetCancelConn();
616
617 if (!AcceptResult(res))
618 {
619 ClearOrSaveResult(res);
620 return 0;
621 }
622
623 if (pset.timing)
624 {
625 INSTR_TIME_SET_CURRENT(after);
626 INSTR_TIME_SUBTRACT(after, before);
627 elapsed_msec = INSTR_TIME_GET_MILLISEC(after);
628 }
629
630 /*
631 * If SIGINT is sent while the query is processing, the interrupt will be
632 * consumed. The user's intention, though, is to cancel the entire watch
633 * process, so detect a sent cancellation request and exit in this case.
634 */
635 if (cancel_pressed)
636 {
637 PQclear(res);
638 return 0;
639 }
640
641 switch (PQresultStatus(res))
642 {
643 case PGRES_TUPLES_OK:
644 printQuery(res, opt, pset.queryFout, false, pset.logfile);
645 break;
646
647 case PGRES_COMMAND_OK:
648 fprintf(pset.queryFout, "%s\n%s\n\n", opt->title, PQcmdStatus(res));
649 break;
650
651 case PGRES_EMPTY_QUERY:
652 pg_log_error("\\watch cannot be used with an empty query");
653 PQclear(res);
654 return -1;
655
656 case PGRES_COPY_OUT:
657 case PGRES_COPY_IN:
658 case PGRES_COPY_BOTH:
659 pg_log_error("\\watch cannot be used with COPY");
660 PQclear(res);
661 return -1;
662
663 default:
664 pg_log_error("unexpected result status for \\watch");
665 PQclear(res);
666 return -1;
667 }
668
669 PQclear(res);
670
671 fflush(pset.queryFout);
672
673 /* Possible microtiming output */
674 if (pset.timing)
675 PrintTiming(elapsed_msec);
676
677 return 1;
678 }
679
680
681 /*
682 * PrintNotifications: check for asynchronous notifications, and print them out
683 */
684 static void
PrintNotifications(void)685 PrintNotifications(void)
686 {
687 PGnotify *notify;
688
689 PQconsumeInput(pset.db);
690 while ((notify = PQnotifies(pset.db)) != NULL)
691 {
692 /* for backward compatibility, only show payload if nonempty */
693 if (notify->extra[0])
694 fprintf(pset.queryFout, _("Asynchronous notification \"%s\" with payload \"%s\" received from server process with PID %d.\n"),
695 notify->relname, notify->extra, notify->be_pid);
696 else
697 fprintf(pset.queryFout, _("Asynchronous notification \"%s\" received from server process with PID %d.\n"),
698 notify->relname, notify->be_pid);
699 fflush(pset.queryFout);
700 PQfreemem(notify);
701 PQconsumeInput(pset.db);
702 }
703 }
704
705
706 /*
707 * PrintQueryTuples: assuming query result is OK, print its tuples
708 *
709 * Returns true if successful, false otherwise.
710 */
711 static bool
PrintQueryTuples(const PGresult * results)712 PrintQueryTuples(const PGresult *results)
713 {
714 bool result = true;
715
716 /* write output to \g argument, if any */
717 if (pset.gfname)
718 {
719 FILE *fout;
720 bool is_pipe;
721
722 if (!openQueryOutputFile(pset.gfname, &fout, &is_pipe))
723 return false;
724 if (is_pipe)
725 disable_sigpipe_trap();
726
727 printQuery(results, &pset.popt, fout, false, pset.logfile);
728 if (ferror(fout))
729 {
730 pg_log_error("could not print result table: %m");
731 result = false;
732 }
733
734 if (is_pipe)
735 {
736 pclose(fout);
737 restore_sigpipe_trap();
738 }
739 else
740 fclose(fout);
741 }
742 else
743 {
744 printQuery(results, &pset.popt, pset.queryFout, false, pset.logfile);
745 if (ferror(pset.queryFout))
746 {
747 pg_log_error("could not print result table: %m");
748 result = false;
749 }
750 }
751
752 return result;
753 }
754
755
756 /*
757 * StoreQueryTuple: assuming query result is OK, save data into variables
758 *
759 * Returns true if successful, false otherwise.
760 */
761 static bool
StoreQueryTuple(const PGresult * result)762 StoreQueryTuple(const PGresult *result)
763 {
764 bool success = true;
765
766 if (PQntuples(result) < 1)
767 {
768 pg_log_error("no rows returned for \\gset");
769 success = false;
770 }
771 else if (PQntuples(result) > 1)
772 {
773 pg_log_error("more than one row returned for \\gset");
774 success = false;
775 }
776 else
777 {
778 int i;
779
780 for (i = 0; i < PQnfields(result); i++)
781 {
782 char *colname = PQfname(result, i);
783 char *varname;
784 char *value;
785
786 /* concatenate prefix and column name */
787 varname = psprintf("%s%s", pset.gset_prefix, colname);
788
789 if (VariableHasHook(pset.vars, varname))
790 {
791 pg_log_warning("attempt to \\gset into specially treated variable \"%s\" ignored",
792 varname);
793 continue;
794 }
795
796 if (!PQgetisnull(result, 0, i))
797 value = PQgetvalue(result, 0, i);
798 else
799 {
800 /* for NULL value, unset rather than set the variable */
801 value = NULL;
802 }
803
804 if (!SetVariable(pset.vars, varname, value))
805 {
806 free(varname);
807 success = false;
808 break;
809 }
810
811 free(varname);
812 }
813 }
814
815 return success;
816 }
817
818
819 /*
820 * ExecQueryTuples: assuming query result is OK, execute each query
821 * result field as a SQL statement
822 *
823 * Returns true if successful, false otherwise.
824 */
825 static bool
ExecQueryTuples(const PGresult * result)826 ExecQueryTuples(const PGresult *result)
827 {
828 bool success = true;
829 int nrows = PQntuples(result);
830 int ncolumns = PQnfields(result);
831 int r,
832 c;
833
834 /*
835 * We must turn off gexec_flag to avoid infinite recursion. Note that
836 * this allows ExecQueryUsingCursor to be applied to the individual query
837 * results. SendQuery prevents it from being applied when fetching the
838 * queries-to-execute, because it can't handle recursion either.
839 */
840 pset.gexec_flag = false;
841
842 for (r = 0; r < nrows; r++)
843 {
844 for (c = 0; c < ncolumns; c++)
845 {
846 if (!PQgetisnull(result, r, c))
847 {
848 const char *query = PQgetvalue(result, r, c);
849
850 /* Abandon execution if cancel_pressed */
851 if (cancel_pressed)
852 goto loop_exit;
853
854 /*
855 * ECHO_ALL mode should echo these queries, but SendQuery
856 * assumes that MainLoop did that, so we have to do it here.
857 */
858 if (pset.echo == PSQL_ECHO_ALL && !pset.singlestep)
859 {
860 puts(query);
861 fflush(stdout);
862 }
863
864 if (!SendQuery(query))
865 {
866 /* Error - abandon execution if ON_ERROR_STOP */
867 success = false;
868 if (pset.on_error_stop)
869 goto loop_exit;
870 }
871 }
872 }
873 }
874
875 loop_exit:
876
877 /*
878 * Restore state. We know gexec_flag was on, else we'd not be here. (We
879 * also know it'll get turned off at end of command, but that's not ours
880 * to do here.)
881 */
882 pset.gexec_flag = true;
883
884 /* Return true if all queries were successful */
885 return success;
886 }
887
888
889 /*
890 * ProcessResult: utility function for use by SendQuery() only
891 *
892 * When our command string contained a COPY FROM STDIN or COPY TO STDOUT,
893 * PQexec() has stopped at the PGresult associated with the first such
894 * command. In that event, we'll marshal data for the COPY and then cycle
895 * through any subsequent PGresult objects.
896 *
897 * When the command string contained no such COPY command, this function
898 * degenerates to an AcceptResult() call.
899 *
900 * Changes its argument to point to the last PGresult of the command string,
901 * or NULL if that result was for a COPY TO STDOUT. (Returning NULL prevents
902 * the command status from being printed, which we want in that case so that
903 * the status line doesn't get taken as part of the COPY data.)
904 *
905 * Returns true on complete success, false otherwise. Possible failure modes
906 * include purely client-side problems; check the transaction status for the
907 * server-side opinion.
908 */
909 static bool
ProcessResult(PGresult ** results)910 ProcessResult(PGresult **results)
911 {
912 bool success = true;
913 bool first_cycle = true;
914
915 for (;;)
916 {
917 ExecStatusType result_status;
918 bool is_copy;
919 PGresult *next_result;
920
921 if (!AcceptResult(*results))
922 {
923 /*
924 * Failure at this point is always a server-side failure or a
925 * failure to submit the command string. Either way, we're
926 * finished with this command string.
927 */
928 success = false;
929 break;
930 }
931
932 result_status = PQresultStatus(*results);
933 switch (result_status)
934 {
935 case PGRES_EMPTY_QUERY:
936 case PGRES_COMMAND_OK:
937 case PGRES_TUPLES_OK:
938 is_copy = false;
939 break;
940
941 case PGRES_COPY_OUT:
942 case PGRES_COPY_IN:
943 is_copy = true;
944 break;
945
946 default:
947 /* AcceptResult() should have caught anything else. */
948 is_copy = false;
949 pg_log_error("unexpected PQresultStatus: %d", result_status);
950 break;
951 }
952
953 if (is_copy)
954 {
955 /*
956 * Marshal the COPY data. Either subroutine will get the
957 * connection out of its COPY state, then call PQresultStatus()
958 * once and report any error.
959 *
960 * For COPY OUT, direct the output to pset.copyStream if it's set,
961 * otherwise to pset.gfname if it's set, otherwise to queryFout.
962 * For COPY IN, use pset.copyStream as data source if it's set,
963 * otherwise cur_cmd_source.
964 */
965 FILE *copystream;
966 PGresult *copy_result;
967
968 SetCancelConn(pset.db);
969 if (result_status == PGRES_COPY_OUT)
970 {
971 bool need_close = false;
972 bool is_pipe = false;
973
974 if (pset.copyStream)
975 {
976 /* invoked by \copy */
977 copystream = pset.copyStream;
978 }
979 else if (pset.gfname)
980 {
981 /* invoked by \g */
982 if (openQueryOutputFile(pset.gfname,
983 ©stream, &is_pipe))
984 {
985 need_close = true;
986 if (is_pipe)
987 disable_sigpipe_trap();
988 }
989 else
990 copystream = NULL; /* discard COPY data entirely */
991 }
992 else
993 {
994 /* fall back to the generic query output stream */
995 copystream = pset.queryFout;
996 }
997
998 success = handleCopyOut(pset.db,
999 copystream,
1000 ©_result)
1001 && success
1002 && (copystream != NULL);
1003
1004 /*
1005 * Suppress status printing if the report would go to the same
1006 * place as the COPY data just went. Note this doesn't
1007 * prevent error reporting, since handleCopyOut did that.
1008 */
1009 if (copystream == pset.queryFout)
1010 {
1011 PQclear(copy_result);
1012 copy_result = NULL;
1013 }
1014
1015 if (need_close)
1016 {
1017 /* close \g argument file/pipe */
1018 if (is_pipe)
1019 {
1020 pclose(copystream);
1021 restore_sigpipe_trap();
1022 }
1023 else
1024 {
1025 fclose(copystream);
1026 }
1027 }
1028 }
1029 else
1030 {
1031 /* COPY IN */
1032 copystream = pset.copyStream ? pset.copyStream : pset.cur_cmd_source;
1033 success = handleCopyIn(pset.db,
1034 copystream,
1035 PQbinaryTuples(*results),
1036 ©_result) && success;
1037 }
1038 ResetCancelConn();
1039
1040 /*
1041 * Replace the PGRES_COPY_OUT/IN result with COPY command's exit
1042 * status, or with NULL if we want to suppress printing anything.
1043 */
1044 PQclear(*results);
1045 *results = copy_result;
1046 }
1047 else if (first_cycle)
1048 {
1049 /* fast path: no COPY commands; PQexec visited all results */
1050 break;
1051 }
1052
1053 /*
1054 * Check PQgetResult() again. In the typical case of a single-command
1055 * string, it will return NULL. Otherwise, we'll have other results
1056 * to process that may include other COPYs. We keep the last result.
1057 */
1058 next_result = PQgetResult(pset.db);
1059 if (!next_result)
1060 break;
1061
1062 PQclear(*results);
1063 *results = next_result;
1064 first_cycle = false;
1065 }
1066
1067 SetResultVariables(*results, success);
1068
1069 /* may need this to recover from conn loss during COPY */
1070 if (!first_cycle && !CheckConnection())
1071 return false;
1072
1073 return success;
1074 }
1075
1076
1077 /*
1078 * PrintQueryStatus: report command status as required
1079 *
1080 * Note: Utility function for use by PrintQueryResults() only.
1081 */
1082 static void
PrintQueryStatus(PGresult * results)1083 PrintQueryStatus(PGresult *results)
1084 {
1085 char buf[16];
1086
1087 if (!pset.quiet)
1088 {
1089 if (pset.popt.topt.format == PRINT_HTML)
1090 {
1091 fputs("<p>", pset.queryFout);
1092 html_escaped_print(PQcmdStatus(results), pset.queryFout);
1093 fputs("</p>\n", pset.queryFout);
1094 }
1095 else
1096 fprintf(pset.queryFout, "%s\n", PQcmdStatus(results));
1097 }
1098
1099 if (pset.logfile)
1100 fprintf(pset.logfile, "%s\n", PQcmdStatus(results));
1101
1102 snprintf(buf, sizeof(buf), "%u", (unsigned int) PQoidValue(results));
1103 SetVariable(pset.vars, "LASTOID", buf);
1104 }
1105
1106
1107 /*
1108 * PrintQueryResults: print out (or store or execute) query results as required
1109 *
1110 * Note: Utility function for use by SendQuery() only.
1111 *
1112 * Returns true if the query executed successfully, false otherwise.
1113 */
1114 static bool
PrintQueryResults(PGresult * results)1115 PrintQueryResults(PGresult *results)
1116 {
1117 bool success;
1118 const char *cmdstatus;
1119
1120 if (!results)
1121 return false;
1122
1123 switch (PQresultStatus(results))
1124 {
1125 case PGRES_TUPLES_OK:
1126 /* store or execute or print the data ... */
1127 if (pset.gset_prefix)
1128 success = StoreQueryTuple(results);
1129 else if (pset.gexec_flag)
1130 success = ExecQueryTuples(results);
1131 else if (pset.crosstab_flag)
1132 success = PrintResultsInCrosstab(results);
1133 else
1134 success = PrintQueryTuples(results);
1135 /* if it's INSERT/UPDATE/DELETE RETURNING, also print status */
1136 cmdstatus = PQcmdStatus(results);
1137 if (strncmp(cmdstatus, "INSERT", 6) == 0 ||
1138 strncmp(cmdstatus, "UPDATE", 6) == 0 ||
1139 strncmp(cmdstatus, "DELETE", 6) == 0)
1140 PrintQueryStatus(results);
1141 break;
1142
1143 case PGRES_COMMAND_OK:
1144 PrintQueryStatus(results);
1145 success = true;
1146 break;
1147
1148 case PGRES_EMPTY_QUERY:
1149 success = true;
1150 break;
1151
1152 case PGRES_COPY_OUT:
1153 case PGRES_COPY_IN:
1154 /* nothing to do here */
1155 success = true;
1156 break;
1157
1158 case PGRES_BAD_RESPONSE:
1159 case PGRES_NONFATAL_ERROR:
1160 case PGRES_FATAL_ERROR:
1161 success = false;
1162 break;
1163
1164 default:
1165 success = false;
1166 pg_log_error("unexpected PQresultStatus: %d",
1167 PQresultStatus(results));
1168 break;
1169 }
1170
1171 fflush(pset.queryFout);
1172
1173 return success;
1174 }
1175
1176
1177 /*
1178 * SendQuery: send the query string to the backend
1179 * (and print out results)
1180 *
1181 * Note: This is the "front door" way to send a query. That is, use it to
1182 * send queries actually entered by the user. These queries will be subject to
1183 * single step mode.
1184 * To send "back door" queries (generated by slash commands, etc.) in a
1185 * controlled way, use PSQLexec().
1186 *
1187 * Returns true if the query executed successfully, false otherwise.
1188 */
1189 bool
SendQuery(const char * query)1190 SendQuery(const char *query)
1191 {
1192 PGresult *results;
1193 PGTransactionStatusType transaction_status;
1194 double elapsed_msec = 0;
1195 bool OK = false;
1196 int i;
1197 bool on_error_rollback_savepoint = false;
1198 static bool on_error_rollback_warning = false;
1199
1200 if (!pset.db)
1201 {
1202 pg_log_error("You are currently not connected to a database.");
1203 goto sendquery_cleanup;
1204 }
1205
1206 if (pset.singlestep)
1207 {
1208 char buf[3];
1209
1210 fflush(stderr);
1211 printf(_("***(Single step mode: verify command)*******************************************\n"
1212 "%s\n"
1213 "***(press return to proceed or enter x and return to cancel)********************\n"),
1214 query);
1215 fflush(stdout);
1216 if (fgets(buf, sizeof(buf), stdin) != NULL)
1217 if (buf[0] == 'x')
1218 goto sendquery_cleanup;
1219 if (cancel_pressed)
1220 goto sendquery_cleanup;
1221 }
1222 else if (pset.echo == PSQL_ECHO_QUERIES)
1223 {
1224 puts(query);
1225 fflush(stdout);
1226 }
1227
1228 if (pset.logfile)
1229 {
1230 fprintf(pset.logfile,
1231 _("********* QUERY **********\n"
1232 "%s\n"
1233 "**************************\n\n"), query);
1234 fflush(pset.logfile);
1235 }
1236
1237 SetCancelConn(pset.db);
1238
1239 transaction_status = PQtransactionStatus(pset.db);
1240
1241 if (transaction_status == PQTRANS_IDLE &&
1242 !pset.autocommit &&
1243 !command_no_begin(query))
1244 {
1245 results = PQexec(pset.db, "BEGIN");
1246 if (PQresultStatus(results) != PGRES_COMMAND_OK)
1247 {
1248 pg_log_info("%s", PQerrorMessage(pset.db));
1249 ClearOrSaveResult(results);
1250 ResetCancelConn();
1251 goto sendquery_cleanup;
1252 }
1253 ClearOrSaveResult(results);
1254 transaction_status = PQtransactionStatus(pset.db);
1255 }
1256
1257 if (transaction_status == PQTRANS_INTRANS &&
1258 pset.on_error_rollback != PSQL_ERROR_ROLLBACK_OFF &&
1259 (pset.cur_cmd_interactive ||
1260 pset.on_error_rollback == PSQL_ERROR_ROLLBACK_ON))
1261 {
1262 if (on_error_rollback_warning == false && pset.sversion < 80000)
1263 {
1264 char sverbuf[32];
1265
1266 pg_log_warning("The server (version %s) does not support savepoints for ON_ERROR_ROLLBACK.",
1267 formatPGVersionNumber(pset.sversion, false,
1268 sverbuf, sizeof(sverbuf)));
1269 on_error_rollback_warning = true;
1270 }
1271 else
1272 {
1273 results = PQexec(pset.db, "SAVEPOINT pg_psql_temporary_savepoint");
1274 if (PQresultStatus(results) != PGRES_COMMAND_OK)
1275 {
1276 pg_log_info("%s", PQerrorMessage(pset.db));
1277 ClearOrSaveResult(results);
1278 ResetCancelConn();
1279 goto sendquery_cleanup;
1280 }
1281 ClearOrSaveResult(results);
1282 on_error_rollback_savepoint = true;
1283 }
1284 }
1285
1286 if (pset.gdesc_flag)
1287 {
1288 /* Describe query's result columns, without executing it */
1289 OK = DescribeQuery(query, &elapsed_msec);
1290 ResetCancelConn();
1291 results = NULL; /* PQclear(NULL) does nothing */
1292 }
1293 else if (pset.fetch_count <= 0 || pset.gexec_flag ||
1294 pset.crosstab_flag || !is_select_command(query))
1295 {
1296 /* Default fetch-it-all-and-print mode */
1297 instr_time before,
1298 after;
1299
1300 if (pset.timing)
1301 INSTR_TIME_SET_CURRENT(before);
1302
1303 results = PQexec(pset.db, query);
1304
1305 /* these operations are included in the timing result: */
1306 ResetCancelConn();
1307 OK = ProcessResult(&results);
1308
1309 if (pset.timing)
1310 {
1311 INSTR_TIME_SET_CURRENT(after);
1312 INSTR_TIME_SUBTRACT(after, before);
1313 elapsed_msec = INSTR_TIME_GET_MILLISEC(after);
1314 }
1315
1316 /* but printing results isn't: */
1317 if (OK && results)
1318 OK = PrintQueryResults(results);
1319 }
1320 else
1321 {
1322 /* Fetch-in-segments mode */
1323 OK = ExecQueryUsingCursor(query, &elapsed_msec);
1324 ResetCancelConn();
1325 results = NULL; /* PQclear(NULL) does nothing */
1326 }
1327
1328 if (!OK && pset.echo == PSQL_ECHO_ERRORS)
1329 pg_log_info("STATEMENT: %s", query);
1330
1331 /* If we made a temporary savepoint, possibly release/rollback */
1332 if (on_error_rollback_savepoint)
1333 {
1334 const char *svptcmd = NULL;
1335
1336 transaction_status = PQtransactionStatus(pset.db);
1337
1338 switch (transaction_status)
1339 {
1340 case PQTRANS_INERROR:
1341 /* We always rollback on an error */
1342 svptcmd = "ROLLBACK TO pg_psql_temporary_savepoint";
1343 break;
1344
1345 case PQTRANS_IDLE:
1346 /* If they are no longer in a transaction, then do nothing */
1347 break;
1348
1349 case PQTRANS_INTRANS:
1350
1351 /*
1352 * Do nothing if they are messing with savepoints themselves:
1353 * If the user did COMMIT AND CHAIN, RELEASE or ROLLBACK, our
1354 * savepoint is gone. If they issued a SAVEPOINT, releasing
1355 * ours would remove theirs.
1356 */
1357 if (results &&
1358 (strcmp(PQcmdStatus(results), "COMMIT") == 0 ||
1359 strcmp(PQcmdStatus(results), "SAVEPOINT") == 0 ||
1360 strcmp(PQcmdStatus(results), "RELEASE") == 0 ||
1361 strcmp(PQcmdStatus(results), "ROLLBACK") == 0))
1362 svptcmd = NULL;
1363 else
1364 svptcmd = "RELEASE pg_psql_temporary_savepoint";
1365 break;
1366
1367 case PQTRANS_ACTIVE:
1368 case PQTRANS_UNKNOWN:
1369 default:
1370 OK = false;
1371 /* PQTRANS_UNKNOWN is expected given a broken connection. */
1372 if (transaction_status != PQTRANS_UNKNOWN || ConnectionUp())
1373 pg_log_error("unexpected transaction status (%d)",
1374 transaction_status);
1375 break;
1376 }
1377
1378 if (svptcmd)
1379 {
1380 PGresult *svptres;
1381
1382 svptres = PQexec(pset.db, svptcmd);
1383 if (PQresultStatus(svptres) != PGRES_COMMAND_OK)
1384 {
1385 pg_log_info("%s", PQerrorMessage(pset.db));
1386 ClearOrSaveResult(svptres);
1387 OK = false;
1388
1389 PQclear(results);
1390 ResetCancelConn();
1391 goto sendquery_cleanup;
1392 }
1393 PQclear(svptres);
1394 }
1395 }
1396
1397 ClearOrSaveResult(results);
1398
1399 /* Possible microtiming output */
1400 if (pset.timing)
1401 PrintTiming(elapsed_msec);
1402
1403 /* check for events that may occur during query execution */
1404
1405 if (pset.encoding != PQclientEncoding(pset.db) &&
1406 PQclientEncoding(pset.db) >= 0)
1407 {
1408 /* track effects of SET CLIENT_ENCODING */
1409 pset.encoding = PQclientEncoding(pset.db);
1410 pset.popt.topt.encoding = pset.encoding;
1411 SetVariable(pset.vars, "ENCODING",
1412 pg_encoding_to_char(pset.encoding));
1413 }
1414
1415 PrintNotifications();
1416
1417 /* perform cleanup that should occur after any attempted query */
1418
1419 sendquery_cleanup:
1420
1421 /* reset \g's output-to-filename trigger */
1422 if (pset.gfname)
1423 {
1424 free(pset.gfname);
1425 pset.gfname = NULL;
1426 }
1427
1428 /* restore print settings if \g changed them */
1429 if (pset.gsavepopt)
1430 {
1431 restorePsetInfo(&pset.popt, pset.gsavepopt);
1432 pset.gsavepopt = NULL;
1433 }
1434
1435 /* reset \gset trigger */
1436 if (pset.gset_prefix)
1437 {
1438 free(pset.gset_prefix);
1439 pset.gset_prefix = NULL;
1440 }
1441
1442 /* reset \gdesc trigger */
1443 pset.gdesc_flag = false;
1444
1445 /* reset \gexec trigger */
1446 pset.gexec_flag = false;
1447
1448 /* reset \crosstabview trigger */
1449 pset.crosstab_flag = false;
1450 for (i = 0; i < lengthof(pset.ctv_args); i++)
1451 {
1452 pg_free(pset.ctv_args[i]);
1453 pset.ctv_args[i] = NULL;
1454 }
1455
1456 return OK;
1457 }
1458
1459
1460 /*
1461 * DescribeQuery: describe the result columns of a query, without executing it
1462 *
1463 * Returns true if the operation executed successfully, false otherwise.
1464 *
1465 * If pset.timing is on, total query time (exclusive of result-printing) is
1466 * stored into *elapsed_msec.
1467 */
1468 static bool
DescribeQuery(const char * query,double * elapsed_msec)1469 DescribeQuery(const char *query, double *elapsed_msec)
1470 {
1471 PGresult *results;
1472 bool OK;
1473 instr_time before,
1474 after;
1475
1476 *elapsed_msec = 0;
1477
1478 if (pset.timing)
1479 INSTR_TIME_SET_CURRENT(before);
1480
1481 /*
1482 * To parse the query but not execute it, we prepare it, using the unnamed
1483 * prepared statement. This is invisible to psql users, since there's no
1484 * way to access the unnamed prepared statement from psql user space. The
1485 * next Parse or Query protocol message would overwrite the statement
1486 * anyway. (So there's no great need to clear it when done, which is a
1487 * good thing because libpq provides no easy way to do that.)
1488 */
1489 results = PQprepare(pset.db, "", query, 0, NULL);
1490 if (PQresultStatus(results) != PGRES_COMMAND_OK)
1491 {
1492 pg_log_info("%s", PQerrorMessage(pset.db));
1493 SetResultVariables(results, false);
1494 ClearOrSaveResult(results);
1495 return false;
1496 }
1497 PQclear(results);
1498
1499 results = PQdescribePrepared(pset.db, "");
1500 OK = AcceptResult(results) &&
1501 (PQresultStatus(results) == PGRES_COMMAND_OK);
1502 if (OK && results)
1503 {
1504 if (PQnfields(results) > 0)
1505 {
1506 PQExpBufferData buf;
1507 int i;
1508
1509 initPQExpBuffer(&buf);
1510
1511 printfPQExpBuffer(&buf,
1512 "SELECT name AS \"%s\", pg_catalog.format_type(tp, tpm) AS \"%s\"\n"
1513 "FROM (VALUES ",
1514 gettext_noop("Column"),
1515 gettext_noop("Type"));
1516
1517 for (i = 0; i < PQnfields(results); i++)
1518 {
1519 const char *name;
1520 char *escname;
1521
1522 if (i > 0)
1523 appendPQExpBufferStr(&buf, ",");
1524
1525 name = PQfname(results, i);
1526 escname = PQescapeLiteral(pset.db, name, strlen(name));
1527
1528 if (escname == NULL)
1529 {
1530 pg_log_info("%s", PQerrorMessage(pset.db));
1531 PQclear(results);
1532 termPQExpBuffer(&buf);
1533 return false;
1534 }
1535
1536 appendPQExpBuffer(&buf, "(%s, '%u'::pg_catalog.oid, %d)",
1537 escname,
1538 PQftype(results, i),
1539 PQfmod(results, i));
1540
1541 PQfreemem(escname);
1542 }
1543
1544 appendPQExpBufferStr(&buf, ") s(name, tp, tpm)");
1545 PQclear(results);
1546
1547 results = PQexec(pset.db, buf.data);
1548 OK = AcceptResult(results);
1549
1550 if (pset.timing)
1551 {
1552 INSTR_TIME_SET_CURRENT(after);
1553 INSTR_TIME_SUBTRACT(after, before);
1554 *elapsed_msec += INSTR_TIME_GET_MILLISEC(after);
1555 }
1556
1557 if (OK && results)
1558 OK = PrintQueryResults(results);
1559
1560 termPQExpBuffer(&buf);
1561 }
1562 else
1563 fprintf(pset.queryFout,
1564 _("The command has no result, or the result has no columns.\n"));
1565 }
1566
1567 SetResultVariables(results, OK);
1568 ClearOrSaveResult(results);
1569
1570 return OK;
1571 }
1572
1573
1574 /*
1575 * ExecQueryUsingCursor: run a SELECT-like query using a cursor
1576 *
1577 * This feature allows result sets larger than RAM to be dealt with.
1578 *
1579 * Returns true if the query executed successfully, false otherwise.
1580 *
1581 * If pset.timing is on, total query time (exclusive of result-printing) is
1582 * stored into *elapsed_msec.
1583 */
1584 static bool
ExecQueryUsingCursor(const char * query,double * elapsed_msec)1585 ExecQueryUsingCursor(const char *query, double *elapsed_msec)
1586 {
1587 bool OK = true;
1588 PGresult *results;
1589 PQExpBufferData buf;
1590 printQueryOpt my_popt = pset.popt;
1591 FILE *fout;
1592 bool is_pipe;
1593 bool is_pager = false;
1594 bool started_txn = false;
1595 int64 total_tuples = 0;
1596 int ntuples;
1597 int fetch_count;
1598 char fetch_cmd[64];
1599 instr_time before,
1600 after;
1601 int flush_error;
1602
1603 *elapsed_msec = 0;
1604
1605 /* initialize print options for partial table output */
1606 my_popt.topt.start_table = true;
1607 my_popt.topt.stop_table = false;
1608 my_popt.topt.prior_records = 0;
1609
1610 if (pset.timing)
1611 INSTR_TIME_SET_CURRENT(before);
1612
1613 /* if we're not in a transaction, start one */
1614 if (PQtransactionStatus(pset.db) == PQTRANS_IDLE)
1615 {
1616 results = PQexec(pset.db, "BEGIN");
1617 OK = AcceptResult(results) &&
1618 (PQresultStatus(results) == PGRES_COMMAND_OK);
1619 ClearOrSaveResult(results);
1620 if (!OK)
1621 return false;
1622 started_txn = true;
1623 }
1624
1625 /* Send DECLARE CURSOR */
1626 initPQExpBuffer(&buf);
1627 appendPQExpBuffer(&buf, "DECLARE _psql_cursor NO SCROLL CURSOR FOR\n%s",
1628 query);
1629
1630 results = PQexec(pset.db, buf.data);
1631 OK = AcceptResult(results) &&
1632 (PQresultStatus(results) == PGRES_COMMAND_OK);
1633 if (!OK)
1634 SetResultVariables(results, OK);
1635 ClearOrSaveResult(results);
1636 termPQExpBuffer(&buf);
1637 if (!OK)
1638 goto cleanup;
1639
1640 if (pset.timing)
1641 {
1642 INSTR_TIME_SET_CURRENT(after);
1643 INSTR_TIME_SUBTRACT(after, before);
1644 *elapsed_msec += INSTR_TIME_GET_MILLISEC(after);
1645 }
1646
1647 /*
1648 * In \gset mode, we force the fetch count to be 2, so that we will throw
1649 * the appropriate error if the query returns more than one row.
1650 */
1651 if (pset.gset_prefix)
1652 fetch_count = 2;
1653 else
1654 fetch_count = pset.fetch_count;
1655
1656 snprintf(fetch_cmd, sizeof(fetch_cmd),
1657 "FETCH FORWARD %d FROM _psql_cursor",
1658 fetch_count);
1659
1660 /* prepare to write output to \g argument, if any */
1661 if (pset.gfname)
1662 {
1663 if (!openQueryOutputFile(pset.gfname, &fout, &is_pipe))
1664 {
1665 OK = false;
1666 goto cleanup;
1667 }
1668 if (is_pipe)
1669 disable_sigpipe_trap();
1670 }
1671 else
1672 {
1673 fout = pset.queryFout;
1674 is_pipe = false; /* doesn't matter */
1675 }
1676
1677 /* clear any pre-existing error indication on the output stream */
1678 clearerr(fout);
1679
1680 for (;;)
1681 {
1682 if (pset.timing)
1683 INSTR_TIME_SET_CURRENT(before);
1684
1685 /* get fetch_count tuples at a time */
1686 results = PQexec(pset.db, fetch_cmd);
1687
1688 if (pset.timing)
1689 {
1690 INSTR_TIME_SET_CURRENT(after);
1691 INSTR_TIME_SUBTRACT(after, before);
1692 *elapsed_msec += INSTR_TIME_GET_MILLISEC(after);
1693 }
1694
1695 if (PQresultStatus(results) != PGRES_TUPLES_OK)
1696 {
1697 /* shut down pager before printing error message */
1698 if (is_pager)
1699 {
1700 ClosePager(fout);
1701 is_pager = false;
1702 }
1703
1704 OK = AcceptResult(results);
1705 Assert(!OK);
1706 SetResultVariables(results, OK);
1707 ClearOrSaveResult(results);
1708 break;
1709 }
1710
1711 if (pset.gset_prefix)
1712 {
1713 /* StoreQueryTuple will complain if not exactly one row */
1714 OK = StoreQueryTuple(results);
1715 ClearOrSaveResult(results);
1716 break;
1717 }
1718
1719 /*
1720 * Note we do not deal with \gdesc, \gexec or \crosstabview modes here
1721 */
1722
1723 ntuples = PQntuples(results);
1724 total_tuples += ntuples;
1725
1726 if (ntuples < fetch_count)
1727 {
1728 /* this is the last result set, so allow footer decoration */
1729 my_popt.topt.stop_table = true;
1730 }
1731 else if (fout == stdout && !is_pager)
1732 {
1733 /*
1734 * If query requires multiple result sets, hack to ensure that
1735 * only one pager instance is used for the whole mess
1736 */
1737 fout = PageOutput(INT_MAX, &(my_popt.topt));
1738 is_pager = true;
1739 }
1740
1741 printQuery(results, &my_popt, fout, is_pager, pset.logfile);
1742
1743 ClearOrSaveResult(results);
1744
1745 /* after the first result set, disallow header decoration */
1746 my_popt.topt.start_table = false;
1747 my_popt.topt.prior_records += ntuples;
1748
1749 /*
1750 * Make sure to flush the output stream, so intermediate results are
1751 * visible to the client immediately. We check the results because if
1752 * the pager dies/exits/etc, there's no sense throwing more data at
1753 * it.
1754 */
1755 flush_error = fflush(fout);
1756
1757 /*
1758 * Check if we are at the end, if a cancel was pressed, or if there
1759 * were any errors either trying to flush out the results, or more
1760 * generally on the output stream at all. If we hit any errors
1761 * writing things to the stream, we presume $PAGER has disappeared and
1762 * stop bothering to pull down more data.
1763 */
1764 if (ntuples < fetch_count || cancel_pressed || flush_error ||
1765 ferror(fout))
1766 break;
1767 }
1768
1769 if (pset.gfname)
1770 {
1771 /* close \g argument file/pipe */
1772 if (is_pipe)
1773 {
1774 pclose(fout);
1775 restore_sigpipe_trap();
1776 }
1777 else
1778 fclose(fout);
1779 }
1780 else if (is_pager)
1781 {
1782 /* close transient pager */
1783 ClosePager(fout);
1784 }
1785
1786 if (OK)
1787 {
1788 /*
1789 * We don't have a PGresult here, and even if we did it wouldn't have
1790 * the right row count, so fake SetResultVariables(). In error cases,
1791 * we already set the result variables above.
1792 */
1793 char buf[32];
1794
1795 SetVariable(pset.vars, "ERROR", "false");
1796 SetVariable(pset.vars, "SQLSTATE", "00000");
1797 snprintf(buf, sizeof(buf), INT64_FORMAT, total_tuples);
1798 SetVariable(pset.vars, "ROW_COUNT", buf);
1799 }
1800
1801 cleanup:
1802 if (pset.timing)
1803 INSTR_TIME_SET_CURRENT(before);
1804
1805 /*
1806 * We try to close the cursor on either success or failure, but on failure
1807 * ignore the result (it's probably just a bleat about being in an aborted
1808 * transaction)
1809 */
1810 results = PQexec(pset.db, "CLOSE _psql_cursor");
1811 if (OK)
1812 {
1813 OK = AcceptResult(results) &&
1814 (PQresultStatus(results) == PGRES_COMMAND_OK);
1815 ClearOrSaveResult(results);
1816 }
1817 else
1818 PQclear(results);
1819
1820 if (started_txn)
1821 {
1822 results = PQexec(pset.db, OK ? "COMMIT" : "ROLLBACK");
1823 OK &= AcceptResult(results) &&
1824 (PQresultStatus(results) == PGRES_COMMAND_OK);
1825 ClearOrSaveResult(results);
1826 }
1827
1828 if (pset.timing)
1829 {
1830 INSTR_TIME_SET_CURRENT(after);
1831 INSTR_TIME_SUBTRACT(after, before);
1832 *elapsed_msec += INSTR_TIME_GET_MILLISEC(after);
1833 }
1834
1835 return OK;
1836 }
1837
1838
1839 /*
1840 * Advance the given char pointer over white space and SQL comments.
1841 */
1842 static const char *
skip_white_space(const char * query)1843 skip_white_space(const char *query)
1844 {
1845 int cnestlevel = 0; /* slash-star comment nest level */
1846
1847 while (*query)
1848 {
1849 int mblen = PQmblenBounded(query, pset.encoding);
1850
1851 /*
1852 * Note: we assume the encoding is a superset of ASCII, so that for
1853 * example "query[0] == '/'" is meaningful. However, we do NOT assume
1854 * that the second and subsequent bytes of a multibyte character
1855 * couldn't look like ASCII characters; so it is critical to advance
1856 * by mblen, not 1, whenever we haven't exactly identified the
1857 * character we are skipping over.
1858 */
1859 if (isspace((unsigned char) *query))
1860 query += mblen;
1861 else if (query[0] == '/' && query[1] == '*')
1862 {
1863 cnestlevel++;
1864 query += 2;
1865 }
1866 else if (cnestlevel > 0 && query[0] == '*' && query[1] == '/')
1867 {
1868 cnestlevel--;
1869 query += 2;
1870 }
1871 else if (cnestlevel == 0 && query[0] == '-' && query[1] == '-')
1872 {
1873 query += 2;
1874
1875 /*
1876 * We have to skip to end of line since any slash-star inside the
1877 * -- comment does NOT start a slash-star comment.
1878 */
1879 while (*query)
1880 {
1881 if (*query == '\n')
1882 {
1883 query++;
1884 break;
1885 }
1886 query += PQmblenBounded(query, pset.encoding);
1887 }
1888 }
1889 else if (cnestlevel > 0)
1890 query += mblen;
1891 else
1892 break; /* found first token */
1893 }
1894
1895 return query;
1896 }
1897
1898
1899 /*
1900 * Check whether a command is one of those for which we should NOT start
1901 * a new transaction block (ie, send a preceding BEGIN).
1902 *
1903 * These include the transaction control statements themselves, plus
1904 * certain statements that the backend disallows inside transaction blocks.
1905 */
1906 static bool
command_no_begin(const char * query)1907 command_no_begin(const char *query)
1908 {
1909 int wordlen;
1910
1911 /*
1912 * First we must advance over any whitespace and comments.
1913 */
1914 query = skip_white_space(query);
1915
1916 /*
1917 * Check word length (since "beginx" is not "begin").
1918 */
1919 wordlen = 0;
1920 while (isalpha((unsigned char) query[wordlen]))
1921 wordlen += PQmblenBounded(&query[wordlen], pset.encoding);
1922
1923 /*
1924 * Transaction control commands. These should include every keyword that
1925 * gives rise to a TransactionStmt in the backend grammar, except for the
1926 * savepoint-related commands.
1927 *
1928 * (We assume that START must be START TRANSACTION, since there is
1929 * presently no other "START foo" command.)
1930 */
1931 if (wordlen == 5 && pg_strncasecmp(query, "abort", 5) == 0)
1932 return true;
1933 if (wordlen == 5 && pg_strncasecmp(query, "begin", 5) == 0)
1934 return true;
1935 if (wordlen == 5 && pg_strncasecmp(query, "start", 5) == 0)
1936 return true;
1937 if (wordlen == 6 && pg_strncasecmp(query, "commit", 6) == 0)
1938 return true;
1939 if (wordlen == 3 && pg_strncasecmp(query, "end", 3) == 0)
1940 return true;
1941 if (wordlen == 8 && pg_strncasecmp(query, "rollback", 8) == 0)
1942 return true;
1943 if (wordlen == 7 && pg_strncasecmp(query, "prepare", 7) == 0)
1944 {
1945 /* PREPARE TRANSACTION is a TC command, PREPARE foo is not */
1946 query += wordlen;
1947
1948 query = skip_white_space(query);
1949
1950 wordlen = 0;
1951 while (isalpha((unsigned char) query[wordlen]))
1952 wordlen += PQmblenBounded(&query[wordlen], pset.encoding);
1953
1954 if (wordlen == 11 && pg_strncasecmp(query, "transaction", 11) == 0)
1955 return true;
1956 return false;
1957 }
1958
1959 /*
1960 * Commands not allowed within transactions. The statements checked for
1961 * here should be exactly those that call PreventInTransactionBlock() in
1962 * the backend.
1963 */
1964 if (wordlen == 6 && pg_strncasecmp(query, "vacuum", 6) == 0)
1965 return true;
1966 if (wordlen == 7 && pg_strncasecmp(query, "cluster", 7) == 0)
1967 {
1968 /* CLUSTER with any arguments is allowed in transactions */
1969 query += wordlen;
1970
1971 query = skip_white_space(query);
1972
1973 if (isalpha((unsigned char) query[0]))
1974 return false; /* has additional words */
1975 return true; /* it's CLUSTER without arguments */
1976 }
1977
1978 if (wordlen == 6 && pg_strncasecmp(query, "create", 6) == 0)
1979 {
1980 query += wordlen;
1981
1982 query = skip_white_space(query);
1983
1984 wordlen = 0;
1985 while (isalpha((unsigned char) query[wordlen]))
1986 wordlen += PQmblenBounded(&query[wordlen], pset.encoding);
1987
1988 if (wordlen == 8 && pg_strncasecmp(query, "database", 8) == 0)
1989 return true;
1990 if (wordlen == 10 && pg_strncasecmp(query, "tablespace", 10) == 0)
1991 return true;
1992
1993 /* CREATE [UNIQUE] INDEX CONCURRENTLY isn't allowed in xacts */
1994 if (wordlen == 6 && pg_strncasecmp(query, "unique", 6) == 0)
1995 {
1996 query += wordlen;
1997
1998 query = skip_white_space(query);
1999
2000 wordlen = 0;
2001 while (isalpha((unsigned char) query[wordlen]))
2002 wordlen += PQmblenBounded(&query[wordlen], pset.encoding);
2003 }
2004
2005 if (wordlen == 5 && pg_strncasecmp(query, "index", 5) == 0)
2006 {
2007 query += wordlen;
2008
2009 query = skip_white_space(query);
2010
2011 wordlen = 0;
2012 while (isalpha((unsigned char) query[wordlen]))
2013 wordlen += PQmblenBounded(&query[wordlen], pset.encoding);
2014
2015 if (wordlen == 12 && pg_strncasecmp(query, "concurrently", 12) == 0)
2016 return true;
2017 }
2018
2019 return false;
2020 }
2021
2022 if (wordlen == 5 && pg_strncasecmp(query, "alter", 5) == 0)
2023 {
2024 query += wordlen;
2025
2026 query = skip_white_space(query);
2027
2028 wordlen = 0;
2029 while (isalpha((unsigned char) query[wordlen]))
2030 wordlen += PQmblenBounded(&query[wordlen], pset.encoding);
2031
2032 /* ALTER SYSTEM isn't allowed in xacts */
2033 if (wordlen == 6 && pg_strncasecmp(query, "system", 6) == 0)
2034 return true;
2035
2036 return false;
2037 }
2038
2039 /*
2040 * Note: these tests will match DROP SYSTEM and REINDEX TABLESPACE, which
2041 * aren't really valid commands so we don't care much. The other four
2042 * possible matches are correct.
2043 */
2044 if ((wordlen == 4 && pg_strncasecmp(query, "drop", 4) == 0) ||
2045 (wordlen == 7 && pg_strncasecmp(query, "reindex", 7) == 0))
2046 {
2047 query += wordlen;
2048
2049 query = skip_white_space(query);
2050
2051 wordlen = 0;
2052 while (isalpha((unsigned char) query[wordlen]))
2053 wordlen += PQmblenBounded(&query[wordlen], pset.encoding);
2054
2055 if (wordlen == 8 && pg_strncasecmp(query, "database", 8) == 0)
2056 return true;
2057 if (wordlen == 6 && pg_strncasecmp(query, "system", 6) == 0)
2058 return true;
2059 if (wordlen == 10 && pg_strncasecmp(query, "tablespace", 10) == 0)
2060 return true;
2061 if (wordlen == 5 && (pg_strncasecmp(query, "index", 5) == 0 ||
2062 pg_strncasecmp(query, "table", 5) == 0))
2063 {
2064 query += wordlen;
2065 query = skip_white_space(query);
2066 wordlen = 0;
2067 while (isalpha((unsigned char) query[wordlen]))
2068 wordlen += PQmblenBounded(&query[wordlen], pset.encoding);
2069
2070 /*
2071 * REINDEX [ TABLE | INDEX ] CONCURRENTLY are not allowed in
2072 * xacts.
2073 */
2074 if (wordlen == 12 && pg_strncasecmp(query, "concurrently", 12) == 0)
2075 return true;
2076 }
2077
2078 /* DROP INDEX CONCURRENTLY isn't allowed in xacts */
2079 if (wordlen == 5 && pg_strncasecmp(query, "index", 5) == 0)
2080 {
2081 query += wordlen;
2082
2083 query = skip_white_space(query);
2084
2085 wordlen = 0;
2086 while (isalpha((unsigned char) query[wordlen]))
2087 wordlen += PQmblenBounded(&query[wordlen], pset.encoding);
2088
2089 if (wordlen == 12 && pg_strncasecmp(query, "concurrently", 12) == 0)
2090 return true;
2091
2092 return false;
2093 }
2094
2095 return false;
2096 }
2097
2098 /* DISCARD ALL isn't allowed in xacts, but other variants are allowed. */
2099 if (wordlen == 7 && pg_strncasecmp(query, "discard", 7) == 0)
2100 {
2101 query += wordlen;
2102
2103 query = skip_white_space(query);
2104
2105 wordlen = 0;
2106 while (isalpha((unsigned char) query[wordlen]))
2107 wordlen += PQmblenBounded(&query[wordlen], pset.encoding);
2108
2109 if (wordlen == 3 && pg_strncasecmp(query, "all", 3) == 0)
2110 return true;
2111 return false;
2112 }
2113
2114 return false;
2115 }
2116
2117
2118 /*
2119 * Check whether the specified command is a SELECT (or VALUES).
2120 */
2121 static bool
is_select_command(const char * query)2122 is_select_command(const char *query)
2123 {
2124 int wordlen;
2125
2126 /*
2127 * First advance over any whitespace, comments and left parentheses.
2128 */
2129 for (;;)
2130 {
2131 query = skip_white_space(query);
2132 if (query[0] == '(')
2133 query++;
2134 else
2135 break;
2136 }
2137
2138 /*
2139 * Check word length (since "selectx" is not "select").
2140 */
2141 wordlen = 0;
2142 while (isalpha((unsigned char) query[wordlen]))
2143 wordlen += PQmblenBounded(&query[wordlen], pset.encoding);
2144
2145 if (wordlen == 6 && pg_strncasecmp(query, "select", 6) == 0)
2146 return true;
2147
2148 if (wordlen == 6 && pg_strncasecmp(query, "values", 6) == 0)
2149 return true;
2150
2151 return false;
2152 }
2153
2154
2155 /*
2156 * Test if the current user is a database superuser.
2157 */
2158 bool
is_superuser(void)2159 is_superuser(void)
2160 {
2161 const char *val;
2162
2163 if (!pset.db)
2164 return false;
2165
2166 val = PQparameterStatus(pset.db, "is_superuser");
2167
2168 if (val && strcmp(val, "on") == 0)
2169 return true;
2170
2171 return false;
2172 }
2173
2174
2175 /*
2176 * Test if the current session uses standard string literals.
2177 */
2178 bool
standard_strings(void)2179 standard_strings(void)
2180 {
2181 const char *val;
2182
2183 if (!pset.db)
2184 return false;
2185
2186 val = PQparameterStatus(pset.db, "standard_conforming_strings");
2187
2188 if (val && strcmp(val, "on") == 0)
2189 return true;
2190
2191 return false;
2192 }
2193
2194
2195 /*
2196 * Return the session user of the current connection.
2197 */
2198 const char *
session_username(void)2199 session_username(void)
2200 {
2201 const char *val;
2202
2203 if (!pset.db)
2204 return NULL;
2205
2206 val = PQparameterStatus(pset.db, "session_authorization");
2207 if (val)
2208 return val;
2209 else
2210 return PQuser(pset.db);
2211 }
2212
2213
2214 /* expand_tilde
2215 *
2216 * substitute '~' with HOME or '~username' with username's home dir
2217 *
2218 */
2219 void
expand_tilde(char ** filename)2220 expand_tilde(char **filename)
2221 {
2222 if (!filename || !(*filename))
2223 return;
2224
2225 /*
2226 * WIN32 doesn't use tilde expansion for file names. Also, it uses tilde
2227 * for short versions of long file names, though the tilde is usually
2228 * toward the end, not at the beginning.
2229 */
2230 #ifndef WIN32
2231
2232 /* try tilde expansion */
2233 if (**filename == '~')
2234 {
2235 char *fn;
2236 char oldp,
2237 *p;
2238 struct passwd *pw;
2239 char home[MAXPGPATH];
2240
2241 fn = *filename;
2242 *home = '\0';
2243
2244 p = fn + 1;
2245 while (*p != '/' && *p != '\0')
2246 p++;
2247
2248 oldp = *p;
2249 *p = '\0';
2250
2251 if (*(fn + 1) == '\0')
2252 get_home_path(home); /* ~ or ~/ only */
2253 else if ((pw = getpwnam(fn + 1)) != NULL)
2254 strlcpy(home, pw->pw_dir, sizeof(home)); /* ~user */
2255
2256 *p = oldp;
2257 if (strlen(home) != 0)
2258 {
2259 char *newfn;
2260
2261 newfn = psprintf("%s%s", home, p);
2262 free(fn);
2263 *filename = newfn;
2264 }
2265 }
2266 #endif
2267 }
2268
2269 /*
2270 * Checks if connection string starts with either of the valid URI prefix
2271 * designators.
2272 *
2273 * Returns the URI prefix length, 0 if the string doesn't contain a URI prefix.
2274 *
2275 * XXX This is a duplicate of the eponymous libpq function.
2276 */
2277 static int
uri_prefix_length(const char * connstr)2278 uri_prefix_length(const char *connstr)
2279 {
2280 /* The connection URI must start with either of the following designators: */
2281 static const char uri_designator[] = "postgresql://";
2282 static const char short_uri_designator[] = "postgres://";
2283
2284 if (strncmp(connstr, uri_designator,
2285 sizeof(uri_designator) - 1) == 0)
2286 return sizeof(uri_designator) - 1;
2287
2288 if (strncmp(connstr, short_uri_designator,
2289 sizeof(short_uri_designator) - 1) == 0)
2290 return sizeof(short_uri_designator) - 1;
2291
2292 return 0;
2293 }
2294
2295 /*
2296 * Recognized connection string either starts with a valid URI prefix or
2297 * contains a "=" in it.
2298 *
2299 * Must be consistent with parse_connection_string: anything for which this
2300 * returns true should at least look like it's parseable by that routine.
2301 *
2302 * XXX This is a duplicate of the eponymous libpq function.
2303 */
2304 bool
recognized_connection_string(const char * connstr)2305 recognized_connection_string(const char *connstr)
2306 {
2307 return uri_prefix_length(connstr) != 0 || strchr(connstr, '=') != NULL;
2308 }
2309