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postgresql/src/bin/psql/common.c

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/*
* psql - the PostgreSQL interactive terminal
*
* Copyright (c) 2000-2024, PostgreSQL Global Development Group
*
* src/bin/psql/common.c
*/
#include "postgres_fe.h"
#include <ctype.h>
#include <limits.h>
#include <math.h>
#include <pwd.h>
#include <signal.h>
#ifndef WIN32
#include <unistd.h> /* for write() */
#else
#include <io.h> /* for _write() */
#include <win32.h>
#endif
#include "command.h"
#include "common.h"
#include "common/logging.h"
#include "copy.h"
#include "crosstabview.h"
#include "fe_utils/cancel.h"
#include "fe_utils/mbprint.h"
#include "fe_utils/string_utils.h"
#include "portability/instr_time.h"
#include "settings.h"
static bool DescribeQuery(const char *query, double *elapsed_msec);
static int ExecQueryAndProcessResults(const char *query,
double *elapsed_msec,
bool *svpt_gone_p,
bool is_watch,
int min_rows,
const printQueryOpt *opt,
FILE *printQueryFout);
static bool command_no_begin(const char *query);
/*
* openQueryOutputFile --- attempt to open a query output file
*
* fname == NULL selects stdout, else an initial '|' selects a pipe,
* else plain file.
*
* Returns output file pointer into *fout, and is-a-pipe flag into *is_pipe.
* Caller is responsible for adjusting SIGPIPE state if it's a pipe.
*
* On error, reports suitable error message and returns false.
*/
bool
openQueryOutputFile(const char *fname, FILE **fout, bool *is_pipe)
{
if (!fname || fname[0] == '\0')
{
*fout = stdout;
*is_pipe = false;
}
else if (*fname == '|')
{
fflush(NULL);
*fout = popen(fname + 1, "w");
*is_pipe = true;
}
else
{
*fout = fopen(fname, "w");
*is_pipe = false;
}
if (*fout == NULL)
{
pg_log_error("%s: %m", fname);
return false;
}
return true;
}
/*
* Check if an output stream for \g needs to be opened, and if yes,
* open it and update the caller's gfile_fout and is_pipe state variables.
* Return true if OK, false if an error occurred.
*/
static bool
SetupGOutput(FILE **gfile_fout, bool *is_pipe)
{
/* If there is a \g file or program, and it's not already open, open it */
if (pset.gfname != NULL && *gfile_fout == NULL)
{
if (openQueryOutputFile(pset.gfname, gfile_fout, is_pipe))
{
if (*is_pipe)
disable_sigpipe_trap();
}
else
return false;
}
return true;
}
/*
* Close the output stream for \g, if we opened it.
*/
static void
CloseGOutput(FILE *gfile_fout, bool is_pipe)
{
if (gfile_fout)
{
if (is_pipe)
{
SetShellResultVariables(pclose(gfile_fout));
restore_sigpipe_trap();
}
else
fclose(gfile_fout);
}
}
/*
* setQFout
* -- handler for -o command line option and \o command
*
* On success, updates pset with the new output file and returns true.
* On failure, returns false without changing pset state.
*/
bool
setQFout(const char *fname)
{
FILE *fout;
bool is_pipe;
/* First make sure we can open the new output file/pipe */
if (!openQueryOutputFile(fname, &fout, &is_pipe))
return false;
/* Close old file/pipe */
if (pset.queryFout && pset.queryFout != stdout && pset.queryFout != stderr)
{
if (pset.queryFoutPipe)
SetShellResultVariables(pclose(pset.queryFout));
else
fclose(pset.queryFout);
}
pset.queryFout = fout;
pset.queryFoutPipe = is_pipe;
/* Adjust SIGPIPE handling appropriately: ignore signal if is_pipe */
set_sigpipe_trap_state(is_pipe);
restore_sigpipe_trap();
return true;
}
/*
* Variable-fetching callback for flex lexer
*
* If the specified variable exists, return its value as a string (malloc'd
* and expected to be freed by the caller); else return NULL.
*
* If "quote" isn't PQUOTE_PLAIN, then return the value suitably quoted and
* escaped for the specified quoting requirement. (Failure in escaping
* should lead to printing an error and returning NULL.)
*
* "passthrough" is the pointer previously given to psql_scan_set_passthrough.
* In psql, passthrough points to a ConditionalStack, which we check to
* determine whether variable expansion is allowed.
*/
char *
psql_get_variable(const char *varname, PsqlScanQuoteType quote,
void *passthrough)
{
char *result = NULL;
const char *value;
/* In an inactive \if branch, suppress all variable substitutions */
if (passthrough && !conditional_active((ConditionalStack) passthrough))
return NULL;
value = GetVariable(pset.vars, varname);
if (!value)
return NULL;
switch (quote)
{
case PQUOTE_PLAIN:
result = pg_strdup(value);
break;
case PQUOTE_SQL_LITERAL:
case PQUOTE_SQL_IDENT:
{
/*
* For these cases, we use libpq's quoting functions, which
* assume the string is in the connection's client encoding.
*/
char *escaped_value;
if (!pset.db)
{
pg_log_error("cannot escape without active connection");
return NULL;
}
if (quote == PQUOTE_SQL_LITERAL)
escaped_value =
PQescapeLiteral(pset.db, value, strlen(value));
else
escaped_value =
PQescapeIdentifier(pset.db, value, strlen(value));
if (escaped_value == NULL)
{
const char *error = PQerrorMessage(pset.db);
pg_log_info("%s", error);
return NULL;
}
/*
* Rather than complicate the lexer's API with a notion of
* which free() routine to use, just pay the price of an extra
* strdup().
*/
result = pg_strdup(escaped_value);
PQfreemem(escaped_value);
break;
}
case PQUOTE_SHELL_ARG:
{
/*
* For this we use appendShellStringNoError, which is
* encoding-agnostic, which is fine since the shell probably
* is too. In any case, the only special character is "'",
* which is not known to appear in valid multibyte characters.
*/
PQExpBufferData buf;
initPQExpBuffer(&buf);
if (!appendShellStringNoError(&buf, value))
{
pg_log_error("shell command argument contains a newline or carriage return: \"%s\"",
value);
free(buf.data);
return NULL;
}
result = buf.data;
break;
}
/* No default: we want a compiler warning for missing cases */
}
return result;
}
/*
* for backend Notice messages (INFO, WARNING, etc)
*/
void
NoticeProcessor(void *arg, const char *message)
{
(void) arg; /* not used */
pg_log_info("%s", message);
}
/*
* Code to support query cancellation
*
* Before we start a query, we enable the SIGINT signal catcher to send a
* cancel request to the backend.
*
* SIGINT is supposed to abort all long-running psql operations, not only
* database queries. In most places, this is accomplished by checking
* cancel_pressed during long-running loops. However, that won't work when
* blocked on user input (in readline() or fgets()). In those places, we
* set sigint_interrupt_enabled true while blocked, instructing the signal
* catcher to longjmp through sigint_interrupt_jmp. We assume readline and
* fgets are coded to handle possible interruption.
*
* On Windows, currently this does not work, so control-C is less useful
* there.
*/
volatile sig_atomic_t sigint_interrupt_enabled = false;
sigjmp_buf sigint_interrupt_jmp;
static void
psql_cancel_callback(void)
{
#ifndef WIN32
/* if we are waiting for input, longjmp out of it */
if (sigint_interrupt_enabled)
{
sigint_interrupt_enabled = false;
siglongjmp(sigint_interrupt_jmp, 1);
}
#endif
/* else, set cancel flag to stop any long-running loops */
cancel_pressed = true;
}
void
psql_setup_cancel_handler(void)
{
setup_cancel_handler(psql_cancel_callback);
}
/* ConnectionUp
*
* Returns whether our backend connection is still there.
*/
static bool
ConnectionUp(void)
{
return PQstatus(pset.db) != CONNECTION_BAD;
}
/* CheckConnection
*
* Verify that we still have a good connection to the backend, and if not,
* see if it can be restored.
*
* Returns true if either the connection was still there, or it could be
* restored successfully; false otherwise. If, however, there was no
* connection and the session is non-interactive, this will exit the program
* with a code of EXIT_BADCONN.
*/
static bool
CheckConnection(void)
{
bool OK;
OK = ConnectionUp();
if (!OK)
{
if (!pset.cur_cmd_interactive)
{
pg_log_error("connection to server was lost");
exit(EXIT_BADCONN);
}
fprintf(stderr, _("The connection to the server was lost. Attempting reset: "));
PQreset(pset.db);
OK = ConnectionUp();
if (!OK)
{
fprintf(stderr, _("Failed.\n"));
/*
* Transition to having no connection; but stash away the failed
* connection so that we can still refer to its parameters in a
* later \connect attempt. Keep the state cleanup here in sync
* with do_connect().
*/
if (pset.dead_conn)
PQfinish(pset.dead_conn);
pset.dead_conn = pset.db;
pset.db = NULL;
ResetCancelConn();
UnsyncVariables();
}
else
{
fprintf(stderr, _("Succeeded.\n"));
/*
* Re-sync, just in case anything changed. Keep this in sync with
* do_connect().
*/
SyncVariables();
connection_warnings(false); /* Must be after SyncVariables */
}
}
return OK;
}
/*
* AcceptResult
*
* Checks whether a result is valid, giving an error message if necessary;
* and ensures that the connection to the backend is still up.
*
* Returns true for valid result, false for error state.
*/
static bool
AcceptResult(const PGresult *result, bool show_error)
{
bool OK;
if (!result)
OK = false;
else
switch (PQresultStatus(result))
{
case PGRES_COMMAND_OK:
case PGRES_TUPLES_OK:
case PGRES_TUPLES_CHUNK:
case PGRES_EMPTY_QUERY:
case PGRES_COPY_IN:
case PGRES_COPY_OUT:
/* Fine, do nothing */
OK = true;
break;
case PGRES_BAD_RESPONSE:
case PGRES_NONFATAL_ERROR:
case PGRES_FATAL_ERROR:
OK = false;
break;
default:
OK = false;
pg_log_error("unexpected PQresultStatus: %d",
PQresultStatus(result));
break;
}
if (!OK && show_error)
{
const char *error = PQerrorMessage(pset.db);
if (strlen(error))
pg_log_info("%s", error);
CheckConnection();
}
return OK;
}
/*
* Set special variables from a query result
* - ERROR: true/false, whether an error occurred on this query
* - SQLSTATE: code of error, or "00000" if no error, or "" if unknown
* - ROW_COUNT: how many rows were returned or affected, or "0"
* - LAST_ERROR_SQLSTATE: same for last error
* - LAST_ERROR_MESSAGE: message of last error
*
* Note: current policy is to apply this only to the results of queries
* entered by the user, not queries generated by slash commands.
*/
static void
SetResultVariables(PGresult *result, bool success)
{
if (success)
{
const char *ntuples = PQcmdTuples(result);
SetVariable(pset.vars, "ERROR", "false");
SetVariable(pset.vars, "SQLSTATE", "00000");
SetVariable(pset.vars, "ROW_COUNT", *ntuples ? ntuples : "0");
}
else
{
const char *code = PQresultErrorField(result, PG_DIAG_SQLSTATE);
const char *mesg = PQresultErrorField(result, PG_DIAG_MESSAGE_PRIMARY);
SetVariable(pset.vars, "ERROR", "true");
/*
* If there is no SQLSTATE code, use an empty string. This can happen
* for libpq-detected errors (e.g., lost connection, ENOMEM).
*/
if (code == NULL)
code = "";
SetVariable(pset.vars, "SQLSTATE", code);
SetVariable(pset.vars, "ROW_COUNT", "0");
SetVariable(pset.vars, "LAST_ERROR_SQLSTATE", code);
SetVariable(pset.vars, "LAST_ERROR_MESSAGE", mesg ? mesg : "");
}
}
/*
* Set special variables from a shell command result
* - SHELL_ERROR: true/false, whether command returned exit code 0
* - SHELL_EXIT_CODE: exit code according to shell conventions
*
* The argument is a wait status as returned by wait(2) or waitpid(2),
* which also applies to pclose(3) and system(3).
*/
void
SetShellResultVariables(int wait_result)
{
char buf[32];
SetVariable(pset.vars, "SHELL_ERROR",
(wait_result == 0) ? "false" : "true");
snprintf(buf, sizeof(buf), "%d", wait_result_to_exit_code(wait_result));
SetVariable(pset.vars, "SHELL_EXIT_CODE", buf);
}
/*
* ClearOrSaveResult
*
* If the result represents an error, remember it for possible display by
* \errverbose. Otherwise, just PQclear() it.
*
* Note: current policy is to apply this to the results of all queries,
* including "back door" queries, for debugging's sake. It's OK to use
* PQclear() directly on results known to not be error results, however.
*/
static void
ClearOrSaveResult(PGresult *result)
{
if (result)
{
switch (PQresultStatus(result))
{
case PGRES_NONFATAL_ERROR:
case PGRES_FATAL_ERROR:
PQclear(pset.last_error_result);
pset.last_error_result = result;
break;
default:
PQclear(result);
break;
}
}
}
/*
* Consume all results
*/
static void
ClearOrSaveAllResults(void)
{
PGresult *result;
while ((result = PQgetResult(pset.db)) != NULL)
ClearOrSaveResult(result);
}
/*
* Print microtiming output. Always print raw milliseconds; if the interval
* is >= 1 second, also break it down into days/hours/minutes/seconds.
*/
static void
PrintTiming(double elapsed_msec)
{
double seconds;
double minutes;
double hours;
double days;
if (elapsed_msec < 1000.0)
{
/* This is the traditional (pre-v10) output format */
printf(_("Time: %.3f ms\n"), elapsed_msec);
return;
}
/*
* Note: we could print just seconds, in a format like %06.3f, when the
* total is less than 1min. But that's hard to interpret unless we tack
* on "s" or otherwise annotate it. Forcing the display to include
* minutes seems like a better solution.
*/
seconds = elapsed_msec / 1000.0;
minutes = floor(seconds / 60.0);
seconds -= 60.0 * minutes;
if (minutes < 60.0)
{
printf(_("Time: %.3f ms (%02d:%06.3f)\n"),
elapsed_msec, (int) minutes, seconds);
return;
}
hours = floor(minutes / 60.0);
minutes -= 60.0 * hours;
if (hours < 24.0)
{
printf(_("Time: %.3f ms (%02d:%02d:%06.3f)\n"),
elapsed_msec, (int) hours, (int) minutes, seconds);
return;
}
days = floor(hours / 24.0);
hours -= 24.0 * days;
printf(_("Time: %.3f ms (%.0f d %02d:%02d:%06.3f)\n"),
elapsed_msec, days, (int) hours, (int) minutes, seconds);
}
/*
* PSQLexec
*
* This is the way to send "backdoor" queries (those not directly entered
* by the user). It is subject to -E but not -e.
*
* Caller is responsible for handling the ensuing processing if a COPY
* command is sent.
*
* Note: we don't bother to check PQclientEncoding; it is assumed that no
* caller uses this path to issue "SET CLIENT_ENCODING".
*/
PGresult *
PSQLexec(const char *query)
{
PGresult *res;
if (!pset.db)
{
pg_log_error("You are currently not connected to a database.");
return NULL;
}
if (pset.echo_hidden != PSQL_ECHO_HIDDEN_OFF)
{
printf(_("/******** QUERY *********/\n"
"%s\n"
"/************************/\n\n"), query);
fflush(stdout);
if (pset.logfile)
{
fprintf(pset.logfile,
_("/******** QUERY *********/\n"
"%s\n"
"/************************/\n\n"), query);
fflush(pset.logfile);
}
if (pset.echo_hidden == PSQL_ECHO_HIDDEN_NOEXEC)
return NULL;
}
SetCancelConn(pset.db);
res = PQexec(pset.db, query);
ResetCancelConn();
if (!AcceptResult(res, true))
{
ClearOrSaveResult(res);
res = NULL;
}
return res;
}
/*
* PSQLexecWatch
*
* This function is used for \watch command to send the query to
* the server and print out the result.
*
* Returns 1 if the query executed successfully, 0 if it cannot be repeated,
* e.g., because of the interrupt, -1 on error.
*/
int
PSQLexecWatch(const char *query, const printQueryOpt *opt, FILE *printQueryFout, int min_rows)
{
bool timing = pset.timing;
double elapsed_msec = 0;
int res;
if (!pset.db)
{
pg_log_error("You are currently not connected to a database.");
return 0;
}
SetCancelConn(pset.db);
res = ExecQueryAndProcessResults(query, &elapsed_msec, NULL, true, min_rows, opt, printQueryFout);
ResetCancelConn();
/* Possible microtiming output */
if (timing)
PrintTiming(elapsed_msec);
return res;
}
/*
* PrintNotifications: check for asynchronous notifications, and print them out
*/
static void
PrintNotifications(void)
{
PGnotify *notify;
PQconsumeInput(pset.db);
while ((notify = PQnotifies(pset.db)) != NULL)
{
/* for backward compatibility, only show payload if nonempty */
if (notify->extra[0])
fprintf(pset.queryFout, _("Asynchronous notification \"%s\" with payload \"%s\" received from server process with PID %d.\n"),
notify->relname, notify->extra, notify->be_pid);
else
fprintf(pset.queryFout, _("Asynchronous notification \"%s\" received from server process with PID %d.\n"),
notify->relname, notify->be_pid);
fflush(pset.queryFout);
PQfreemem(notify);
PQconsumeInput(pset.db);
}
}
/*
* PrintQueryTuples: assuming query result is OK, print its tuples
*
* We use the options given by opt unless that's NULL, in which case
* we use pset.popt.
*
* Output is to printQueryFout unless that's NULL, in which case
* we use pset.queryFout.
*
* Returns true if successful, false otherwise.
*/
static bool
PrintQueryTuples(const PGresult *result, const printQueryOpt *opt,
FILE *printQueryFout)
{
bool ok = true;
FILE *fout = printQueryFout ? printQueryFout : pset.queryFout;
printQuery(result, opt ? opt : &pset.popt, fout, false, pset.logfile);
fflush(fout);
if (ferror(fout))
{
pg_log_error("could not print result table: %m");
ok = false;
}
return ok;
}
/*
* StoreQueryTuple: assuming query result is OK, save data into variables
*
* Returns true if successful, false otherwise.
*/
static bool
StoreQueryTuple(const PGresult *result)
{
bool success = true;
if (PQntuples(result) < 1)
{
pg_log_error("no rows returned for \\gset");
success = false;
}
else if (PQntuples(result) > 1)
{
pg_log_error("more than one row returned for \\gset");
success = false;
}
else
{
int i;
for (i = 0; i < PQnfields(result); i++)
{
char *colname = PQfname(result, i);
char *varname;
char *value;
/* concatenate prefix and column name */
varname = psprintf("%s%s", pset.gset_prefix, colname);
if (VariableHasHook(pset.vars, varname))
{
pg_log_warning("attempt to \\gset into specially treated variable \"%s\" ignored",
varname);
continue;
}
if (!PQgetisnull(result, 0, i))
value = PQgetvalue(result, 0, i);
else
{
/* for NULL value, unset rather than set the variable */
value = NULL;
}
if (!SetVariable(pset.vars, varname, value))
{
free(varname);
success = false;
break;
}
free(varname);
}
}
return success;
}
/*
* ExecQueryTuples: assuming query result is OK, execute each query
* result field as a SQL statement
*
* Returns true if successful, false otherwise.
*/
static bool
ExecQueryTuples(const PGresult *result)
{
bool success = true;
int nrows = PQntuples(result);
int ncolumns = PQnfields(result);
int r,
c;
/*
* We must turn off gexec_flag to avoid infinite recursion.
*/
pset.gexec_flag = false;
for (r = 0; r < nrows; r++)
{
for (c = 0; c < ncolumns; c++)
{
if (!PQgetisnull(result, r, c))
{
const char *query = PQgetvalue(result, r, c);
/* Abandon execution if cancel_pressed */
if (cancel_pressed)
goto loop_exit;
/*
* ECHO_ALL mode should echo these queries, but SendQuery
* assumes that MainLoop did that, so we have to do it here.
*/
if (pset.echo == PSQL_ECHO_ALL && !pset.singlestep)
{
puts(query);
fflush(stdout);
}
if (!SendQuery(query))
{
/* Error - abandon execution if ON_ERROR_STOP */
success = false;
if (pset.on_error_stop)
goto loop_exit;
}
}
}
}
loop_exit:
/*
* Restore state. We know gexec_flag was on, else we'd not be here. (We
* also know it'll get turned off at end of command, but that's not ours
* to do here.)
*/
pset.gexec_flag = true;
/* Return true if all queries were successful */
return success;
}
/*
* Marshal the COPY data. Either path will get the
* connection out of its COPY state, then call PQresultStatus()
* once and report any error. Return whether all was ok.
*
* For COPY OUT, direct the output to copystream, or discard if that's NULL.
* For COPY IN, use pset.copyStream as data source if it's set,
* otherwise cur_cmd_source.
*
* Update *resultp if further processing is necessary; set to NULL otherwise.
* Return a result when queryFout can safely output a result status: on COPY
* IN, or on COPY OUT if written to something other than pset.queryFout.
* Returning NULL prevents the command status from being printed, which we
* want if the status line doesn't get taken as part of the COPY data.
*/
static bool
HandleCopyResult(PGresult **resultp, FILE *copystream)
{
bool success;
PGresult *copy_result;
ExecStatusType result_status = PQresultStatus(*resultp);
Assert(result_status == PGRES_COPY_OUT ||
result_status == PGRES_COPY_IN);
SetCancelConn(pset.db);
if (result_status == PGRES_COPY_OUT)
{
success = handleCopyOut(pset.db,
copystream,
&copy_result)
&& (copystream != NULL);
/*
* Suppress status printing if the report would go to the same place
* as the COPY data just went. Note this doesn't prevent error
* reporting, since handleCopyOut did that.
*/
if (copystream == pset.queryFout)
{
PQclear(copy_result);
copy_result = NULL;
}
}
else
{
/* COPY IN */
/* Ignore the copystream argument passed to the function */
copystream = pset.copyStream ? pset.copyStream : pset.cur_cmd_source;
success = handleCopyIn(pset.db,
copystream,
PQbinaryTuples(*resultp),
&copy_result);
}
ResetCancelConn();
/*
* Replace the PGRES_COPY_OUT/IN result with COPY command's exit status,
* or with NULL if we want to suppress printing anything.
*/
PQclear(*resultp);
*resultp = copy_result;
return success;
}
/*
* PrintQueryStatus: report command status as required
*/
static void
PrintQueryStatus(PGresult *result, FILE *printQueryFout)
{
char buf[16];
const char *cmdstatus = PQcmdStatus(result);
FILE *fout = printQueryFout ? printQueryFout : pset.queryFout;
/* Do nothing if it's a TUPLES_OK result that isn't from RETURNING */
if (PQresultStatus(result) == PGRES_TUPLES_OK)
{
if (!(strncmp(cmdstatus, "INSERT", 6) == 0 ||
strncmp(cmdstatus, "UPDATE", 6) == 0 ||
strncmp(cmdstatus, "DELETE", 6) == 0 ||
strncmp(cmdstatus, "MERGE", 5) == 0))
return;
}
if (!pset.quiet)
{
if (pset.popt.topt.format == PRINT_HTML)
{
fputs("<p>", fout);
html_escaped_print(cmdstatus, fout);
fputs("</p>\n", fout);
}
else
fprintf(fout, "%s\n", cmdstatus);
fflush(fout);
}
if (pset.logfile)
fprintf(pset.logfile, "%s\n", cmdstatus);
snprintf(buf, sizeof(buf), "%u", (unsigned int) PQoidValue(result));
SetVariable(pset.vars, "LASTOID", buf);
}
/*
* PrintQueryResult: print out (or store or execute) query result as required
*
* last is true if this is the last result of a command string.
* opt and printQueryFout are defined as for PrintQueryTuples.
* printStatusFout is where to send command status; NULL means pset.queryFout.
*
* Returns true if the query executed successfully, false otherwise.
*/
static bool
PrintQueryResult(PGresult *result, bool last,
const printQueryOpt *opt, FILE *printQueryFout,
FILE *printStatusFout)
{
bool success;
if (!result)
return false;
switch (PQresultStatus(result))
{
case PGRES_TUPLES_OK:
/* store or execute or print the data ... */
if (last && pset.gset_prefix)
success = StoreQueryTuple(result);
else if (last && pset.gexec_flag)
success = ExecQueryTuples(result);
else if (last && pset.crosstab_flag)
success = PrintResultInCrosstab(result);
else if (last || pset.show_all_results)
success = PrintQueryTuples(result, opt, printQueryFout);
else
success = true;
/*
* If it's INSERT/UPDATE/DELETE/MERGE RETURNING, also print
* status.
*/
if (last || pset.show_all_results)
PrintQueryStatus(result, printStatusFout);
break;
case PGRES_COMMAND_OK:
if (last || pset.show_all_results)
PrintQueryStatus(result, printStatusFout);
success = true;
break;
case PGRES_EMPTY_QUERY:
success = true;
break;
case PGRES_COPY_OUT:
case PGRES_COPY_IN:
/* nothing to do here: already processed */
success = true;
break;
case PGRES_BAD_RESPONSE:
case PGRES_NONFATAL_ERROR:
case PGRES_FATAL_ERROR:
success = false;
break;
default:
success = false;
pg_log_error("unexpected PQresultStatus: %d",
PQresultStatus(result));
break;
}
return success;
}
/*
* SendQuery: send the query string to the backend
* (and print out result)
*
* Note: This is the "front door" way to send a query. That is, use it to
* send queries actually entered by the user. These queries will be subject to
* single step mode.
* To send "back door" queries (generated by slash commands, etc.) in a
* controlled way, use PSQLexec().
*
* Returns true if the query executed successfully, false otherwise.
*/
bool
SendQuery(const char *query)
{
bool timing = pset.timing;
PGTransactionStatusType transaction_status;
double elapsed_msec = 0;
bool OK = false;
int i;
bool on_error_rollback_savepoint = false;
bool svpt_gone = false;
if (!pset.db)
{
pg_log_error("You are currently not connected to a database.");
goto sendquery_cleanup;
}
if (pset.singlestep)
{
char buf[3];
fflush(stderr);
printf(_("/**(Single step mode: verify command)******************************************/\n"
"%s\n"
"/**(press return to proceed or enter x and return to cancel)*******************/\n"),
query);
fflush(stdout);
if (fgets(buf, sizeof(buf), stdin) != NULL)
if (buf[0] == 'x')
goto sendquery_cleanup;
if (cancel_pressed)
goto sendquery_cleanup;
}
else if (pset.echo == PSQL_ECHO_QUERIES)
{
puts(query);
fflush(stdout);
}
if (pset.logfile)
{
fprintf(pset.logfile,
_("/******** QUERY *********/\n"
"%s\n"
"/************************/\n\n"), query);
fflush(pset.logfile);
}
SetCancelConn(pset.db);
transaction_status = PQtransactionStatus(pset.db);
if (transaction_status == PQTRANS_IDLE &&
!pset.autocommit &&
!command_no_begin(query))
{
PGresult *result;
result = PQexec(pset.db, "BEGIN");
if (PQresultStatus(result) != PGRES_COMMAND_OK)
{
pg_log_info("%s", PQerrorMessage(pset.db));
ClearOrSaveResult(result);
goto sendquery_cleanup;
}
ClearOrSaveResult(result);
transaction_status = PQtransactionStatus(pset.db);
}
if (transaction_status == PQTRANS_INTRANS &&
pset.on_error_rollback != PSQL_ERROR_ROLLBACK_OFF &&
(pset.cur_cmd_interactive ||
pset.on_error_rollback == PSQL_ERROR_ROLLBACK_ON))
{
PGresult *result;
result = PQexec(pset.db, "SAVEPOINT pg_psql_temporary_savepoint");
if (PQresultStatus(result) != PGRES_COMMAND_OK)
{
pg_log_info("%s", PQerrorMessage(pset.db));
ClearOrSaveResult(result);
goto sendquery_cleanup;
}
ClearOrSaveResult(result);
on_error_rollback_savepoint = true;
}
if (pset.gdesc_flag)
{
/* Describe query's result columns, without executing it */
OK = DescribeQuery(query, &elapsed_msec);
}
else
{
/* Default fetch-and-print mode */
OK = (ExecQueryAndProcessResults(query, &elapsed_msec, &svpt_gone, false, 0, NULL, NULL) > 0);
}
if (!OK && pset.echo == PSQL_ECHO_ERRORS)
pg_log_info("STATEMENT: %s", query);
/* If we made a temporary savepoint, possibly release/rollback */
if (on_error_rollback_savepoint)
{
const char *svptcmd = NULL;
transaction_status = PQtransactionStatus(pset.db);
switch (transaction_status)
{
case PQTRANS_INERROR:
/* We always rollback on an error */
svptcmd = "ROLLBACK TO pg_psql_temporary_savepoint";
break;
case PQTRANS_IDLE:
/* If they are no longer in a transaction, then do nothing */
break;
case PQTRANS_INTRANS:
/*
* Release our savepoint, but do nothing if they are messing
* with savepoints themselves
*/
if (!svpt_gone)
svptcmd = "RELEASE pg_psql_temporary_savepoint";
break;
case PQTRANS_ACTIVE:
case PQTRANS_UNKNOWN:
default:
OK = false;
/* PQTRANS_UNKNOWN is expected given a broken connection. */
if (transaction_status != PQTRANS_UNKNOWN || ConnectionUp())
pg_log_error("unexpected transaction status (%d)",
transaction_status);
break;
}
if (svptcmd)
{
PGresult *svptres;
svptres = PQexec(pset.db, svptcmd);
if (PQresultStatus(svptres) != PGRES_COMMAND_OK)
{
pg_log_info("%s", PQerrorMessage(pset.db));
ClearOrSaveResult(svptres);
OK = false;
goto sendquery_cleanup;
}
PQclear(svptres);
}
}
/* Possible microtiming output */
if (timing)
PrintTiming(elapsed_msec);
/* check for events that may occur during query execution */
if (pset.encoding != PQclientEncoding(pset.db) &&
PQclientEncoding(pset.db) >= 0)
{
/* track effects of SET CLIENT_ENCODING */
pset.encoding = PQclientEncoding(pset.db);
pset.popt.topt.encoding = pset.encoding;
SetVariable(pset.vars, "ENCODING",
pg_encoding_to_char(pset.encoding));
}
PrintNotifications();
/* perform cleanup that should occur after any attempted query */
sendquery_cleanup:
/* global cancellation reset */
ResetCancelConn();
/* reset \g's output-to-filename trigger */
if (pset.gfname)
{
free(pset.gfname);
pset.gfname = NULL;
}
/* restore print settings if \g changed them */
if (pset.gsavepopt)
{
restorePsetInfo(&pset.popt, pset.gsavepopt);
pset.gsavepopt = NULL;
}
/* clean up after \bind */
if (pset.bind_flag)
{
for (i = 0; i < pset.bind_nparams; i++)
free(pset.bind_params[i]);
free(pset.bind_params);
pset.bind_params = NULL;
pset.bind_flag = false;
}
/* reset \gset trigger */
if (pset.gset_prefix)
{
free(pset.gset_prefix);
pset.gset_prefix = NULL;
}
/* reset \gdesc trigger */
pset.gdesc_flag = false;
/* reset \gexec trigger */
pset.gexec_flag = false;
/* reset \crosstabview trigger */
pset.crosstab_flag = false;
for (i = 0; i < lengthof(pset.ctv_args); i++)
{
pg_free(pset.ctv_args[i]);
pset.ctv_args[i] = NULL;
}
return OK;
}
/*
* DescribeQuery: describe the result columns of a query, without executing it
*
* Returns true if the operation executed successfully, false otherwise.
*
* If pset.timing is on, total query time (exclusive of result-printing) is
* stored into *elapsed_msec.
*/
static bool
DescribeQuery(const char *query, double *elapsed_msec)
{
bool timing = pset.timing;
PGresult *result;
bool OK;
instr_time before,
after;
*elapsed_msec = 0;
if (timing)
INSTR_TIME_SET_CURRENT(before);
else
INSTR_TIME_SET_ZERO(before);
/*
* To parse the query but not execute it, we prepare it, using the unnamed
* prepared statement. This is invisible to psql users, since there's no
* way to access the unnamed prepared statement from psql user space. The
* next Parse or Query protocol message would overwrite the statement
* anyway. (So there's no great need to clear it when done, which is a
* good thing because libpq provides no easy way to do that.)
*/
result = PQprepare(pset.db, "", query, 0, NULL);
if (PQresultStatus(result) != PGRES_COMMAND_OK)
{
pg_log_info("%s", PQerrorMessage(pset.db));
SetResultVariables(result, false);
ClearOrSaveResult(result);
return false;
}
PQclear(result);
result = PQdescribePrepared(pset.db, "");
OK = AcceptResult(result, true) &&
(PQresultStatus(result) == PGRES_COMMAND_OK);
if (OK && result)
{
if (PQnfields(result) > 0)
{
PQExpBufferData buf;
int i;
initPQExpBuffer(&buf);
printfPQExpBuffer(&buf,
"SELECT name AS \"%s\", pg_catalog.format_type(tp, tpm) AS \"%s\"\n"
"FROM (VALUES ",
gettext_noop("Column"),
gettext_noop("Type"));
for (i = 0; i < PQnfields(result); i++)
{
const char *name;
char *escname;
if (i > 0)
appendPQExpBufferStr(&buf, ",");
name = PQfname(result, i);
escname = PQescapeLiteral(pset.db, name, strlen(name));
if (escname == NULL)
{
pg_log_info("%s", PQerrorMessage(pset.db));
PQclear(result);
termPQExpBuffer(&buf);
return false;
}
appendPQExpBuffer(&buf, "(%s, '%u'::pg_catalog.oid, %d)",
escname,
PQftype(result, i),
PQfmod(result, i));
PQfreemem(escname);
}
appendPQExpBufferStr(&buf, ") s(name, tp, tpm)");
PQclear(result);
result = PQexec(pset.db, buf.data);
OK = AcceptResult(result, true);
if (timing)
{
INSTR_TIME_SET_CURRENT(after);
INSTR_TIME_SUBTRACT(after, before);
*elapsed_msec += INSTR_TIME_GET_MILLISEC(after);
}
if (OK && result)
OK = PrintQueryResult(result, true, NULL, NULL, NULL);
termPQExpBuffer(&buf);
}
else
fprintf(pset.queryFout,
_("The command has no result, or the result has no columns.\n"));
}
SetResultVariables(result, OK);
ClearOrSaveResult(result);
return OK;
}
/*
* ExecQueryAndProcessResults: utility function for use by SendQuery()
* and PSQLexecWatch().
*
* Sends query and cycles through PGresult objects.
*
* If our command string contained a COPY FROM STDIN or COPY TO STDOUT, the
* PGresult associated with these commands must be processed by providing an
* input or output stream. In that event, we'll marshal data for the COPY.
*
* For other commands, the results are processed normally, depending on their
* status.
*
* When invoked from \watch, is_watch is true and min_rows is the value
* of that option, or 0 if it wasn't set.
*
* Returns 1 on complete success, 0 on interrupt and -1 or errors. Possible
* failure modes include purely client-side problems; check the transaction
* status for the server-side opinion.
*
* Note that on a combined query, failure does not mean that nothing was
* committed.
*/
static int
ExecQueryAndProcessResults(const char *query,
double *elapsed_msec, bool *svpt_gone_p,
bool is_watch, int min_rows,
const printQueryOpt *opt, FILE *printQueryFout)
{
bool timing = pset.timing;
bool success;
bool return_early = false;
instr_time before,
after;
PGresult *result;
FILE *gfile_fout = NULL;
bool gfile_is_pipe = false;
if (timing)
INSTR_TIME_SET_CURRENT(before);
else
INSTR_TIME_SET_ZERO(before);
if (pset.bind_flag)
success = PQsendQueryParams(pset.db, query, pset.bind_nparams, NULL, (const char *const *) pset.bind_params, NULL, NULL, 0);
else
success = PQsendQuery(pset.db, query);
if (!success)
{
const char *error = PQerrorMessage(pset.db);
if (strlen(error))
pg_log_info("%s", error);
CheckConnection();
return -1;
}
/*
* Fetch the result in chunks if FETCH_COUNT is set, except when:
*
* * SHOW_ALL_RESULTS is false, since that requires us to complete the
* query before we can tell if its results should be displayed.
*
* * We're doing \crosstab, which likewise needs to see all the rows at
* once.
*
* * We're doing \gexec: we must complete the data fetch to make the
* connection free for issuing the resulting commands.
*
* * We're doing \gset: only one result row is allowed anyway.
*
* * We're doing \watch: users probably don't want us to force use of the
* pager for that, plus chunking could break the min_rows check.
*/
if (pset.fetch_count > 0 && pset.show_all_results &&
!pset.crosstab_flag && !pset.gexec_flag &&
!pset.gset_prefix && !is_watch)
{
if (!PQsetChunkedRowsMode(pset.db, pset.fetch_count))
pg_log_warning("fetching results in chunked mode failed");
}
/*
* If SIGINT is sent while the query is processing, the interrupt will be
* consumed. The user's intention, though, is to cancel the entire watch
* process, so detect a sent cancellation request and exit in this case.
*/
if (is_watch && cancel_pressed)
{
ClearOrSaveAllResults();
return 0;
}
/* first result */
result = PQgetResult(pset.db);
if (min_rows > 0 && PQntuples(result) < min_rows)
{
return_early = true;
}
while (result != NULL)
{
ExecStatusType result_status;
bool is_chunked_result = false;
PGresult *next_result;
bool last;
if (!AcceptResult(result, false))
{
/*
* Some error occurred, either a server-side failure or a failure
* to submit the command string. Record that.
*/
const char *error = PQresultErrorMessage(result);
if (strlen(error))
pg_log_info("%s", error);
CheckConnection();
if (!is_watch)
SetResultVariables(result, false);
/* keep the result status before clearing it */
result_status = PQresultStatus(result);
ClearOrSaveResult(result);
success = false;
/*
* switch to next result
*/
if (result_status == PGRES_COPY_BOTH ||
result_status == PGRES_COPY_OUT ||
result_status == PGRES_COPY_IN)
/*
* For some obscure reason PQgetResult does *not* return a
* NULL in copy cases despite the result having been cleared,
* but keeps returning an "empty" result that we have to
* ignore manually.
*/
result = NULL;
else
result = PQgetResult(pset.db);
/*
* Get current timing measure in case an error occurs
*/
if (timing)
{
INSTR_TIME_SET_CURRENT(after);
INSTR_TIME_SUBTRACT(after, before);
*elapsed_msec = INSTR_TIME_GET_MILLISEC(after);
}
continue;
}
else if (svpt_gone_p && !*svpt_gone_p)
{
/*
* Check if the user ran any command that would destroy our
* internal savepoint: If the user did COMMIT AND CHAIN, RELEASE
* or ROLLBACK, our savepoint is gone. If they issued a SAVEPOINT,
* releasing ours would remove theirs.
*/
const char *cmd = PQcmdStatus(result);
*svpt_gone_p = (strcmp(cmd, "COMMIT") == 0 ||
strcmp(cmd, "SAVEPOINT") == 0 ||
strcmp(cmd, "RELEASE") == 0 ||
strcmp(cmd, "ROLLBACK") == 0);
}
result_status = PQresultStatus(result);
/* must handle COPY before changing the current result */
Assert(result_status != PGRES_COPY_BOTH);
if (result_status == PGRES_COPY_IN ||
result_status == PGRES_COPY_OUT)
{
FILE *copy_stream = NULL;
/*
* For COPY OUT, direct the output to the default place (probably
* a pager pipe) for \watch, or to pset.copyStream for \copy,
* otherwise to pset.gfname if that's set, otherwise to
* pset.queryFout.
*/
if (result_status == PGRES_COPY_OUT)
{
if (is_watch)
{
/* invoked by \watch */
copy_stream = printQueryFout ? printQueryFout : pset.queryFout;
}
else if (pset.copyStream)
{
/* invoked by \copy */
copy_stream = pset.copyStream;
}
else if (pset.gfname)
{
/* COPY followed by \g filename or \g |program */
success &= SetupGOutput(&gfile_fout, &gfile_is_pipe);
if (gfile_fout)
copy_stream = gfile_fout;
}
else
{
/* fall back to the generic query output stream */
copy_stream = pset.queryFout;
}
}
/*
* Even if the output stream could not be opened, we call
* HandleCopyResult() with a NULL output stream to collect and
* discard the COPY data.
*/
success &= HandleCopyResult(&result, copy_stream);
}
/* If we have a chunked result, collect and print all chunks */
if (result_status == PGRES_TUPLES_CHUNK)
{
FILE *tuples_fout = printQueryFout ? printQueryFout : pset.queryFout;
printQueryOpt my_popt = opt ? *opt : pset.popt;
int64 total_tuples = 0;
bool is_pager = false;
int flush_error = 0;
/* initialize print options for partial table output */
my_popt.topt.start_table = true;
my_popt.topt.stop_table = false;
my_popt.topt.prior_records = 0;
/* open \g file if needed */
success &= SetupGOutput(&gfile_fout, &gfile_is_pipe);
if (gfile_fout)
tuples_fout = gfile_fout;
/* force use of pager for any chunked resultset going to stdout */
if (success && tuples_fout == stdout)
{
tuples_fout = PageOutput(INT_MAX, &(my_popt.topt));
is_pager = true;
}
do
{
/*
* Display the current chunk of results, unless the output
* stream stopped working or we got cancelled. We skip use of
* PrintQueryResult and go directly to printQuery, so that we
* can pass the correct is_pager value and because we don't
* want PrintQueryStatus to happen yet. Above, we rejected
* use of chunking for all cases in which PrintQueryResult
* would send the result to someplace other than printQuery.
*/
if (success && !flush_error && !cancel_pressed)
{
printQuery(result, &my_popt, tuples_fout, is_pager, pset.logfile);
flush_error = fflush(tuples_fout);
}
/* after the first result set, disallow header decoration */
my_popt.topt.start_table = false;
/* count tuples before dropping the result */
my_popt.topt.prior_records += PQntuples(result);
total_tuples += PQntuples(result);
ClearOrSaveResult(result);
/* get the next result, loop if it's PGRES_TUPLES_CHUNK */
result = PQgetResult(pset.db);
} while (PQresultStatus(result) == PGRES_TUPLES_CHUNK);
/* We expect an empty PGRES_TUPLES_OK, else there's a problem */
if (PQresultStatus(result) == PGRES_TUPLES_OK)
{
char buf[32];
Assert(PQntuples(result) == 0);
/* Display the footer using the empty result */
if (success && !flush_error && !cancel_pressed)
{
my_popt.topt.stop_table = true;
printQuery(result, &my_popt, tuples_fout, is_pager, pset.logfile);
fflush(tuples_fout);
}
if (is_pager)
ClosePager(tuples_fout);
/*
* It's possible the data is from a RETURNING clause, in which
* case we need to print query status.
*/
PrintQueryStatus(result, printQueryFout);
/*
* We must do a fake SetResultVariables(), since we don't have
* a PGresult corresponding to the whole query.
*/
SetVariable(pset.vars, "ERROR", "false");
SetVariable(pset.vars, "SQLSTATE", "00000");
snprintf(buf, sizeof(buf), INT64_FORMAT, total_tuples);
SetVariable(pset.vars, "ROW_COUNT", buf);
/* Prevent SetResultVariables call below */
is_chunked_result = true;
/* Clear the empty result so it isn't printed below */
ClearOrSaveResult(result);
result = NULL;
}
else
{
/* Probably an error report, so close the pager and print it */
if (is_pager)
ClosePager(tuples_fout);
success &= AcceptResult(result, true);
/* SetResultVariables and ClearOrSaveResult happen below */
}
}
/*
* Check PQgetResult() again. In the typical case of a single-command
* string, it will return NULL. Otherwise, we'll have other results
* to process. We need to do that to check whether this is the last.
*/
next_result = PQgetResult(pset.db);
last = (next_result == NULL);
/*
* Update current timing measure.
*
* It will include the display of previous results, if any. This
* cannot be helped because the server goes on processing further
* queries anyway while the previous ones are being displayed. The
* parallel execution of the client display hides the server time when
* it is shorter.
*
* With combined queries, timing must be understood as an upper bound
* of the time spent processing them.
*/
if (timing)
{
INSTR_TIME_SET_CURRENT(after);
INSTR_TIME_SUBTRACT(after, before);
*elapsed_msec = INSTR_TIME_GET_MILLISEC(after);
}
/* this may or may not print something depending on settings */
if (result != NULL)
{
/*
* If results need to be printed into the file specified by \g,
* open it, unless we already did. Note that when pset.gfname is
* set, the passed-in value of printQueryFout is not used for
* tuple output, but it's still used for status output.
*/
FILE *tuples_fout = printQueryFout;
if (PQresultStatus(result) == PGRES_TUPLES_OK)
success &= SetupGOutput(&gfile_fout, &gfile_is_pipe);
if (gfile_fout)
tuples_fout = gfile_fout;
if (success)
success &= PrintQueryResult(result, last, opt,
tuples_fout, printQueryFout);
}
/* set variables from last result, unless dealt with elsewhere */
if (last && !is_watch && !is_chunked_result)
SetResultVariables(result, success);
ClearOrSaveResult(result);
result = next_result;
if (cancel_pressed)
{
/* drop this next result, as well as any others not yet read */
ClearOrSaveResult(result);
ClearOrSaveAllResults();
break;
}
}
/* close \g file if we opened it */
CloseGOutput(gfile_fout, gfile_is_pipe);
/* may need this to recover from conn loss during COPY */
if (!CheckConnection())
return -1;
if (cancel_pressed || return_early)
return 0;
return success ? 1 : -1;
}
/*
* Advance the given char pointer over white space and SQL comments.
*/
static const char *
skip_white_space(const char *query)
{
int cnestlevel = 0; /* slash-star comment nest level */
while (*query)
{
int mblen = PQmblenBounded(query, pset.encoding);
/*
* Note: we assume the encoding is a superset of ASCII, so that for
* example "query[0] == '/'" is meaningful. However, we do NOT assume
* that the second and subsequent bytes of a multibyte character
* couldn't look like ASCII characters; so it is critical to advance
* by mblen, not 1, whenever we haven't exactly identified the
* character we are skipping over.
*/
if (isspace((unsigned char) *query))
query += mblen;
else if (query[0] == '/' && query[1] == '*')
{
cnestlevel++;
query += 2;
}
else if (cnestlevel > 0 && query[0] == '*' && query[1] == '/')
{
cnestlevel--;
query += 2;
}
else if (cnestlevel == 0 && query[0] == '-' && query[1] == '-')
{
query += 2;
/*
* We have to skip to end of line since any slash-star inside the
* -- comment does NOT start a slash-star comment.
*/
while (*query)
{
if (*query == '\n')
{
query++;
break;
}
query += PQmblenBounded(query, pset.encoding);
}
}
else if (cnestlevel > 0)
query += mblen;
else
break; /* found first token */
}
return query;
}
/*
* Check whether a command is one of those for which we should NOT start
* a new transaction block (ie, send a preceding BEGIN).
*
* These include the transaction control statements themselves, plus
* certain statements that the backend disallows inside transaction blocks.
*/
static bool
command_no_begin(const char *query)
{
int wordlen;
/*
* First we must advance over any whitespace and comments.
*/
query = skip_white_space(query);
/*
* Check word length (since "beginx" is not "begin").
*/
wordlen = 0;
while (isalpha((unsigned char) query[wordlen]))
wordlen += PQmblenBounded(&query[wordlen], pset.encoding);
/*
* Transaction control commands. These should include every keyword that
* gives rise to a TransactionStmt in the backend grammar, except for the
* savepoint-related commands.
*
* (We assume that START must be START TRANSACTION, since there is
* presently no other "START foo" command.)
*/
if (wordlen == 5 && pg_strncasecmp(query, "abort", 5) == 0)
return true;
if (wordlen == 5 && pg_strncasecmp(query, "begin", 5) == 0)
return true;
if (wordlen == 5 && pg_strncasecmp(query, "start", 5) == 0)
return true;
if (wordlen == 6 && pg_strncasecmp(query, "commit", 6) == 0)
return true;
if (wordlen == 3 && pg_strncasecmp(query, "end", 3) == 0)
return true;
if (wordlen == 8 && pg_strncasecmp(query, "rollback", 8) == 0)
return true;
if (wordlen == 7 && pg_strncasecmp(query, "prepare", 7) == 0)
{
/* PREPARE TRANSACTION is a TC command, PREPARE foo is not */
query += wordlen;
query = skip_white_space(query);
wordlen = 0;
while (isalpha((unsigned char) query[wordlen]))
wordlen += PQmblenBounded(&query[wordlen], pset.encoding);
if (wordlen == 11 && pg_strncasecmp(query, "transaction", 11) == 0)
return true;
return false;
}
/*
* Commands not allowed within transactions. The statements checked for
* here should be exactly those that call PreventInTransactionBlock() in
* the backend.
*/
if (wordlen == 6 && pg_strncasecmp(query, "vacuum", 6) == 0)
return true;
if (wordlen == 7 && pg_strncasecmp(query, "cluster", 7) == 0)
{
/* CLUSTER with any arguments is allowed in transactions */
query += wordlen;
query = skip_white_space(query);
if (isalpha((unsigned char) query[0]))
return false; /* has additional words */
return true; /* it's CLUSTER without arguments */
}
if (wordlen == 6 && pg_strncasecmp(query, "create", 6) == 0)
{
query += wordlen;
query = skip_white_space(query);
wordlen = 0;
while (isalpha((unsigned char) query[wordlen]))
wordlen += PQmblenBounded(&query[wordlen], pset.encoding);
if (wordlen == 8 && pg_strncasecmp(query, "database", 8) == 0)
return true;
if (wordlen == 10 && pg_strncasecmp(query, "tablespace", 10) == 0)
return true;
/* CREATE [UNIQUE] INDEX CONCURRENTLY isn't allowed in xacts */
if (wordlen == 6 && pg_strncasecmp(query, "unique", 6) == 0)
{
query += wordlen;
query = skip_white_space(query);
wordlen = 0;
while (isalpha((unsigned char) query[wordlen]))
wordlen += PQmblenBounded(&query[wordlen], pset.encoding);
}
if (wordlen == 5 && pg_strncasecmp(query, "index", 5) == 0)
{
query += wordlen;
query = skip_white_space(query);
wordlen = 0;
while (isalpha((unsigned char) query[wordlen]))
wordlen += PQmblenBounded(&query[wordlen], pset.encoding);
if (wordlen == 12 && pg_strncasecmp(query, "concurrently", 12) == 0)
return true;
}
return false;
}
if (wordlen == 5 && pg_strncasecmp(query, "alter", 5) == 0)
{
query += wordlen;
query = skip_white_space(query);
wordlen = 0;
while (isalpha((unsigned char) query[wordlen]))
wordlen += PQmblenBounded(&query[wordlen], pset.encoding);
/* ALTER SYSTEM isn't allowed in xacts */
if (wordlen == 6 && pg_strncasecmp(query, "system", 6) == 0)
return true;
return false;
}
/*
* Note: these tests will match DROP SYSTEM and REINDEX TABLESPACE, which
* aren't really valid commands so we don't care much. The other four
* possible matches are correct.
*/
if ((wordlen == 4 && pg_strncasecmp(query, "drop", 4) == 0) ||
(wordlen == 7 && pg_strncasecmp(query, "reindex", 7) == 0))
{
query += wordlen;
query = skip_white_space(query);
wordlen = 0;
while (isalpha((unsigned char) query[wordlen]))
wordlen += PQmblenBounded(&query[wordlen], pset.encoding);
if (wordlen == 8 && pg_strncasecmp(query, "database", 8) == 0)
return true;
if (wordlen == 6 && pg_strncasecmp(query, "system", 6) == 0)
return true;
if (wordlen == 10 && pg_strncasecmp(query, "tablespace", 10) == 0)
return true;
if (wordlen == 5 && (pg_strncasecmp(query, "index", 5) == 0 ||
pg_strncasecmp(query, "table", 5) == 0))
{
query += wordlen;
query = skip_white_space(query);
wordlen = 0;
while (isalpha((unsigned char) query[wordlen]))
wordlen += PQmblenBounded(&query[wordlen], pset.encoding);
/*
* REINDEX [ TABLE | INDEX ] CONCURRENTLY are not allowed in
* xacts.
*/
if (wordlen == 12 && pg_strncasecmp(query, "concurrently", 12) == 0)
return true;
}
/* DROP INDEX CONCURRENTLY isn't allowed in xacts */
if (wordlen == 5 && pg_strncasecmp(query, "index", 5) == 0)
{
query += wordlen;
query = skip_white_space(query);
wordlen = 0;
while (isalpha((unsigned char) query[wordlen]))
wordlen += PQmblenBounded(&query[wordlen], pset.encoding);
if (wordlen == 12 && pg_strncasecmp(query, "concurrently", 12) == 0)
return true;
return false;
}
return false;
}
/* DISCARD ALL isn't allowed in xacts, but other variants are allowed. */
if (wordlen == 7 && pg_strncasecmp(query, "discard", 7) == 0)
{
query += wordlen;
query = skip_white_space(query);
wordlen = 0;
while (isalpha((unsigned char) query[wordlen]))
wordlen += PQmblenBounded(&query[wordlen], pset.encoding);
if (wordlen == 3 && pg_strncasecmp(query, "all", 3) == 0)
return true;
return false;
}
return false;
}
/*
* Test if the current user is a database superuser.
*/
bool
is_superuser(void)
{
const char *val;
if (!pset.db)
return false;
val = PQparameterStatus(pset.db, "is_superuser");
if (val && strcmp(val, "on") == 0)
return true;
return false;
}
/*
* Test if the current session uses standard string literals.
*/
bool
standard_strings(void)
{
const char *val;
if (!pset.db)
return false;
val = PQparameterStatus(pset.db, "standard_conforming_strings");
if (val && strcmp(val, "on") == 0)
return true;
return false;
}
/*
* Return the session user of the current connection.
*/
const char *
session_username(void)
{
const char *val;
if (!pset.db)
return NULL;
val = PQparameterStatus(pset.db, "session_authorization");
if (val)
return val;
else
return PQuser(pset.db);
}
/* expand_tilde
*
* substitute '~' with HOME or '~username' with username's home dir
*
*/
void
expand_tilde(char **filename)
{
if (!filename || !(*filename))
return;
/*
* WIN32 doesn't use tilde expansion for file names. Also, it uses tilde
* for short versions of long file names, though the tilde is usually
* toward the end, not at the beginning.
*/
#ifndef WIN32
/* try tilde expansion */
if (**filename == '~')
{
char *fn;
char oldp,
*p;
struct passwd *pw;
char home[MAXPGPATH];
fn = *filename;
*home = '\0';
p = fn + 1;
while (*p != '/' && *p != '\0')
p++;
oldp = *p;
*p = '\0';
if (*(fn + 1) == '\0')
get_home_path(home); /* ~ or ~/ only */
else if ((pw = getpwnam(fn + 1)) != NULL)
strlcpy(home, pw->pw_dir, sizeof(home)); /* ~user */
*p = oldp;
if (strlen(home) != 0)
{
char *newfn;
newfn = psprintf("%s%s", home, p);
free(fn);
*filename = newfn;
}
}
#endif
}
/*
* Checks if connection string starts with either of the valid URI prefix
* designators.
*
* Returns the URI prefix length, 0 if the string doesn't contain a URI prefix.
*
* XXX This is a duplicate of the eponymous libpq function.
*/
static int
uri_prefix_length(const char *connstr)
{
/* The connection URI must start with either of the following designators: */
static const char uri_designator[] = "postgresql://";
static const char short_uri_designator[] = "postgres://";
if (strncmp(connstr, uri_designator,
sizeof(uri_designator) - 1) == 0)
return sizeof(uri_designator) - 1;
if (strncmp(connstr, short_uri_designator,
sizeof(short_uri_designator) - 1) == 0)
return sizeof(short_uri_designator) - 1;
return 0;
}
/*
* Recognized connection string either starts with a valid URI prefix or
* contains a "=" in it.
*
* Must be consistent with parse_connection_string: anything for which this
* returns true should at least look like it's parseable by that routine.
*
* XXX This is a duplicate of the eponymous libpq function.
*/
bool
recognized_connection_string(const char *connstr)
{
return uri_prefix_length(connstr) != 0 || strchr(connstr, '=') != NULL;
}
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