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postgresql/src/bin/psql/common.c

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/*
* psql - the PostgreSQL interactive terminal
*
* Copyright (c) 2000-2019, PostgreSQL Global Development Group
*
* src/bin/psql/common.c
*/
#include "postgres_fe.h"
#include <ctype.h>
#include <limits.h>
#include <math.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/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 bool ExecQueryUsingCursor(const char *query, double *elapsed_msec);
static bool command_no_begin(const char *query);
static bool is_select_command(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 == '|')
{
*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;
}
/*
* 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)
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. Note that sending the cancel directly from
* the signal handler is safe because PQcancel() is written to make it
* so. We use write() to report to stderr because it's better to use simple
* facilities in a signal handler.
*
* On win32, the signal canceling happens on a separate thread, because
* that's how SetConsoleCtrlHandler works. The PQcancel function is safe
* for this (unlike PQrequestCancel). However, a CRITICAL_SECTION is required
* to protect the PGcancel structure against being changed while the signal
* thread is using it.
*
* 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. (XXX currently this does
* not work on win32, so control-C is less useful there)
*/
volatile bool sigint_interrupt_enabled = false;
sigjmp_buf sigint_interrupt_jmp;
static PGcancel *volatile cancelConn = NULL;
#ifdef WIN32
static CRITICAL_SECTION cancelConnLock;
#endif
/*
* Write a simple string to stderr --- must be safe in a signal handler.
* We ignore the write() result since there's not much we could do about it.
* Certain compilers make that harder than it ought to be.
*/
#define write_stderr(str) \
do { \
const char *str_ = (str); \
int rc_; \
rc_ = write(fileno(stderr), str_, strlen(str_)); \
(void) rc_; \
} while (0)
#ifndef WIN32
static void
handle_sigint(SIGNAL_ARGS)
{
int save_errno = errno;
char errbuf[256];
/* if we are waiting for input, longjmp out of it */
if (sigint_interrupt_enabled)
{
sigint_interrupt_enabled = false;
siglongjmp(sigint_interrupt_jmp, 1);
}
/* else, set cancel flag to stop any long-running loops */
cancel_pressed = true;
/* and send QueryCancel if we are processing a database query */
if (cancelConn != NULL)
{
if (PQcancel(cancelConn, errbuf, sizeof(errbuf)))
write_stderr("Cancel request sent\n");
else
{
write_stderr("Could not send cancel request: ");
write_stderr(errbuf);
}
}
errno = save_errno; /* just in case the write changed it */
}
void
setup_cancel_handler(void)
{
pqsignal(SIGINT, handle_sigint);
}
#else /* WIN32 */
static BOOL WINAPI
consoleHandler(DWORD dwCtrlType)
{
char errbuf[256];
if (dwCtrlType == CTRL_C_EVENT ||
dwCtrlType == CTRL_BREAK_EVENT)
{
/*
* Can't longjmp here, because we are in wrong thread :-(
*/
/* set cancel flag to stop any long-running loops */
cancel_pressed = true;
/* and send QueryCancel if we are processing a database query */
EnterCriticalSection(&cancelConnLock);
if (cancelConn != NULL)
{
if (PQcancel(cancelConn, errbuf, sizeof(errbuf)))
write_stderr("Cancel request sent\n");
else
{
write_stderr("Could not send cancel request: ");
write_stderr(errbuf);
}
}
LeaveCriticalSection(&cancelConnLock);
return TRUE;
}
else
/* Return FALSE for any signals not being handled */
return FALSE;
}
void
setup_cancel_handler(void)
{
InitializeCriticalSection(&cancelConnLock);
SetConsoleCtrlHandler(consoleHandler, TRUE);
}
#endif /* WIN32 */
/* 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_fatal("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. Keep this bit in sync with
* do_connect().
*/
PQfinish(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;
}
/*
* SetCancelConn
*
* Set cancelConn to point to the current database connection.
*/
void
SetCancelConn(void)
{
PGcancel *oldCancelConn;
#ifdef WIN32
EnterCriticalSection(&cancelConnLock);
#endif
/* Free the old one if we have one */
oldCancelConn = cancelConn;
/* be sure handle_sigint doesn't use pointer while freeing */
cancelConn = NULL;
if (oldCancelConn != NULL)
PQfreeCancel(oldCancelConn);
cancelConn = PQgetCancel(pset.db);
#ifdef WIN32
LeaveCriticalSection(&cancelConnLock);
#endif
}
/*
* ResetCancelConn
*
* Free the current cancel connection, if any, and set to NULL.
*/
void
ResetCancelConn(void)
{
PGcancel *oldCancelConn;
#ifdef WIN32
EnterCriticalSection(&cancelConnLock);
#endif
oldCancelConn = cancelConn;
/* be sure handle_sigint doesn't use pointer while freeing */
cancelConn = NULL;
if (oldCancelConn != NULL)
PQfreeCancel(oldCancelConn);
#ifdef WIN32
LeaveCriticalSection(&cancelConnLock);
#endif
}
/*
* 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 OK;
if (!result)
OK = false;
else
switch (PQresultStatus(result))
{
case PGRES_COMMAND_OK:
case PGRES_TUPLES_OK:
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)
{
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 *results, bool success)
{
if (success)
{
const char *ntuples = PQcmdTuples(results);
SetVariable(pset.vars, "ERROR", "false");
SetVariable(pset.vars, "SQLSTATE", "00000");
SetVariable(pset.vars, "ROW_COUNT", *ntuples ? ntuples : "0");
}
else
{
const char *code = PQresultErrorField(results, PG_DIAG_SQLSTATE);
const char *mesg = PQresultErrorField(results, 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 : "");
}
}
/*
* 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:
if (pset.last_error_result)
PQclear(pset.last_error_result);
pset.last_error_result = result;
break;
default:
PQclear(result);
break;
}
}
}
/*
* 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();
res = PQexec(pset.db, query);
ResetCancelConn();
if (!AcceptResult(res))
{
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 results.
*
* 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)
{
PGresult *res;
double elapsed_msec = 0;
instr_time before;
instr_time after;
if (!pset.db)
{
pg_log_error("You are currently not connected to a database.");
return 0;
}
SetCancelConn();
if (pset.timing)
INSTR_TIME_SET_CURRENT(before);
res = PQexec(pset.db, query);
ResetCancelConn();
if (!AcceptResult(res))
{
ClearOrSaveResult(res);
return 0;
}
if (pset.timing)
{
INSTR_TIME_SET_CURRENT(after);
INSTR_TIME_SUBTRACT(after, before);
elapsed_msec = INSTR_TIME_GET_MILLISEC(after);
}
/*
* 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 (cancel_pressed)
{
PQclear(res);
return 0;
}
switch (PQresultStatus(res))
{
case PGRES_TUPLES_OK:
printQuery(res, opt, pset.queryFout, false, pset.logfile);
break;
case PGRES_COMMAND_OK:
fprintf(pset.queryFout, "%s\n%s\n\n", opt->title, PQcmdStatus(res));
break;
case PGRES_EMPTY_QUERY:
pg_log_error("\\watch cannot be used with an empty query");
PQclear(res);
return -1;
case PGRES_COPY_OUT:
case PGRES_COPY_IN:
case PGRES_COPY_BOTH:
pg_log_error("\\watch cannot be used with COPY");
PQclear(res);
return -1;
default:
pg_log_error("unexpected result status for \\watch");
PQclear(res);
return -1;
}
PQclear(res);
fflush(pset.queryFout);
/* Possible microtiming output */
if (pset.timing)
PrintTiming(elapsed_msec);
return 1;
}
/*
* 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
*
* Returns true if successful, false otherwise.
*/
static bool
PrintQueryTuples(const PGresult *results)
{
printQueryOpt my_popt = pset.popt;
/* one-shot expanded output requested via \gx */
if (pset.g_expanded)
my_popt.topt.expanded = 1;
/* write output to \g argument, if any */
if (pset.gfname)
{
FILE *fout;
bool is_pipe;
if (!openQueryOutputFile(pset.gfname, &fout, &is_pipe))
return false;
if (is_pipe)
disable_sigpipe_trap();
printQuery(results, &my_popt, fout, false, pset.logfile);
if (is_pipe)
{
pclose(fout);
restore_sigpipe_trap();
}
else
fclose(fout);
}
else
printQuery(results, &my_popt, pset.queryFout, false, pset.logfile);
return true;
}
/*
* 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 (!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. Note that
* this allows ExecQueryUsingCursor to be applied to the individual query
* results. SendQuery prevents it from being applied when fetching the
* queries-to-execute, because it can't handle recursion either.
*/
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;
}
/*
* ProcessResult: utility function for use by SendQuery() only
*
* When our command string contained a COPY FROM STDIN or COPY TO STDOUT,
* PQexec() has stopped at the PGresult associated with the first such
* command. In that event, we'll marshal data for the COPY and then cycle
* through any subsequent PGresult objects.
*
* When the command string contained no such COPY command, this function
* degenerates to an AcceptResult() call.
*
* Changes its argument to point to the last PGresult of the command string,
* or NULL if that result was for a COPY TO STDOUT. (Returning NULL prevents
* the command status from being printed, which we want in that case so that
* the status line doesn't get taken as part of the COPY data.)
*
* Returns true on complete success, false otherwise. Possible failure modes
* include purely client-side problems; check the transaction status for the
* server-side opinion.
*/
static bool
ProcessResult(PGresult **results)
{
bool success = true;
bool first_cycle = true;
for (;;)
{
ExecStatusType result_status;
bool is_copy;
PGresult *next_result;
if (!AcceptResult(*results))
{
/*
* Failure at this point is always a server-side failure or a
* failure to submit the command string. Either way, we're
* finished with this command string.
*/
success = false;
break;
}
result_status = PQresultStatus(*results);
switch (result_status)
{
case PGRES_EMPTY_QUERY:
case PGRES_COMMAND_OK:
case PGRES_TUPLES_OK:
is_copy = false;
break;
case PGRES_COPY_OUT:
case PGRES_COPY_IN:
is_copy = true;
break;
default:
/* AcceptResult() should have caught anything else. */
is_copy = false;
pg_log_error("unexpected PQresultStatus: %d", result_status);
break;
}
if (is_copy)
{
/*
* Marshal the COPY data. Either subroutine will get the
* connection out of its COPY state, then call PQresultStatus()
* once and report any error.
*
* For COPY OUT, direct the output to pset.copyStream if it's set,
* otherwise to pset.gfname if it's set, otherwise to queryFout.
* For COPY IN, use pset.copyStream as data source if it's set,
* otherwise cur_cmd_source.
*/
FILE *copystream;
PGresult *copy_result;
SetCancelConn();
if (result_status == PGRES_COPY_OUT)
{
bool need_close = false;
bool is_pipe = false;
if (pset.copyStream)
{
/* invoked by \copy */
copystream = pset.copyStream;
}
else if (pset.gfname)
{
/* invoked by \g */
if (openQueryOutputFile(pset.gfname,
&copystream, &is_pipe))
{
need_close = true;
if (is_pipe)
disable_sigpipe_trap();
}
else
copystream = NULL; /* discard COPY data entirely */
}
else
{
/* fall back to the generic query output stream */
copystream = pset.queryFout;
}
success = handleCopyOut(pset.db,
copystream,
&copy_result)
&& success
&& (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;
}
if (need_close)
{
/* close \g argument file/pipe */
if (is_pipe)
{
pclose(copystream);
restore_sigpipe_trap();
}
else
{
fclose(copystream);
}
}
}
else
{
/* COPY IN */
copystream = pset.copyStream ? pset.copyStream : pset.cur_cmd_source;
success = handleCopyIn(pset.db,
copystream,
PQbinaryTuples(*results),
&copy_result) && success;
}
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(*results);
*results = copy_result;
}
else if (first_cycle)
{
/* fast path: no COPY commands; PQexec visited all results */
break;
}
/*
* Check PQgetResult() again. In the typical case of a single-command
* string, it will return NULL. Otherwise, we'll have other results
* to process that may include other COPYs. We keep the last result.
*/
next_result = PQgetResult(pset.db);
if (!next_result)
break;
PQclear(*results);
*results = next_result;
first_cycle = false;
}
SetResultVariables(*results, success);
/* may need this to recover from conn loss during COPY */
if (!first_cycle && !CheckConnection())
return false;
return success;
}
/*
* PrintQueryStatus: report command status as required
*
* Note: Utility function for use by PrintQueryResults() only.
*/
static void
PrintQueryStatus(PGresult *results)
{
char buf[16];
if (!pset.quiet)
{
if (pset.popt.topt.format == PRINT_HTML)
{
fputs("<p>", pset.queryFout);
html_escaped_print(PQcmdStatus(results), pset.queryFout);
fputs("</p>\n", pset.queryFout);
}
else
fprintf(pset.queryFout, "%s\n", PQcmdStatus(results));
}
if (pset.logfile)
fprintf(pset.logfile, "%s\n", PQcmdStatus(results));
snprintf(buf, sizeof(buf), "%u", (unsigned int) PQoidValue(results));
SetVariable(pset.vars, "LASTOID", buf);
}
/*
* PrintQueryResults: print out (or store or execute) query results as required
*
* Note: Utility function for use by SendQuery() only.
*
* Returns true if the query executed successfully, false otherwise.
*/
static bool
PrintQueryResults(PGresult *results)
{
bool success;
const char *cmdstatus;
if (!results)
return false;
switch (PQresultStatus(results))
{
case PGRES_TUPLES_OK:
/* store or execute or print the data ... */
if (pset.gset_prefix)
success = StoreQueryTuple(results);
else if (pset.gexec_flag)
success = ExecQueryTuples(results);
else if (pset.crosstab_flag)
success = PrintResultsInCrosstab(results);
else
success = PrintQueryTuples(results);
/* if it's INSERT/UPDATE/DELETE RETURNING, also print status */
cmdstatus = PQcmdStatus(results);
if (strncmp(cmdstatus, "INSERT", 6) == 0 ||
strncmp(cmdstatus, "UPDATE", 6) == 0 ||
strncmp(cmdstatus, "DELETE", 6) == 0)
PrintQueryStatus(results);
break;
case PGRES_COMMAND_OK:
PrintQueryStatus(results);
success = true;
break;
case PGRES_EMPTY_QUERY:
success = true;
break;
case PGRES_COPY_OUT:
case PGRES_COPY_IN:
/* nothing to do here */
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(results));
break;
}
fflush(pset.queryFout);
return success;
}
/*
* SendQuery: send the query string to the backend
* (and print out results)
*
* 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)
{
PGresult *results;
PGTransactionStatusType transaction_status;
double elapsed_msec = 0;
bool OK = false;
int i;
bool on_error_rollback_savepoint = false;
static bool on_error_rollback_warning = 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();
transaction_status = PQtransactionStatus(pset.db);
if (transaction_status == PQTRANS_IDLE &&
!pset.autocommit &&
!command_no_begin(query))
{
results = PQexec(pset.db, "BEGIN");
if (PQresultStatus(results) != PGRES_COMMAND_OK)
{
pg_log_info("%s", PQerrorMessage(pset.db));
ClearOrSaveResult(results);
ResetCancelConn();
goto sendquery_cleanup;
}
ClearOrSaveResult(results);
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))
{
if (on_error_rollback_warning == false && pset.sversion < 80000)
{
char sverbuf[32];
pg_log_warning("The server (version %s) does not support savepoints for ON_ERROR_ROLLBACK.",
formatPGVersionNumber(pset.sversion, false,
sverbuf, sizeof(sverbuf)));
on_error_rollback_warning = true;
}
else
{
results = PQexec(pset.db, "SAVEPOINT pg_psql_temporary_savepoint");
if (PQresultStatus(results) != PGRES_COMMAND_OK)
{
pg_log_info("%s", PQerrorMessage(pset.db));
ClearOrSaveResult(results);
ResetCancelConn();
goto sendquery_cleanup;
}
ClearOrSaveResult(results);
on_error_rollback_savepoint = true;
}
}
if (pset.gdesc_flag)
{
/* Describe query's result columns, without executing it */
OK = DescribeQuery(query, &elapsed_msec);
ResetCancelConn();
results = NULL; /* PQclear(NULL) does nothing */
}
else if (pset.fetch_count <= 0 || pset.gexec_flag ||
pset.crosstab_flag || !is_select_command(query))
{
/* Default fetch-it-all-and-print mode */
instr_time before,
after;
if (pset.timing)
INSTR_TIME_SET_CURRENT(before);
results = PQexec(pset.db, query);
/* these operations are included in the timing result: */
ResetCancelConn();
OK = ProcessResult(&results);
if (pset.timing)
{
INSTR_TIME_SET_CURRENT(after);
INSTR_TIME_SUBTRACT(after, before);
elapsed_msec = INSTR_TIME_GET_MILLISEC(after);
}
/* but printing results isn't: */
if (OK && results)
OK = PrintQueryResults(results);
}
else
{
/* Fetch-in-segments mode */
OK = ExecQueryUsingCursor(query, &elapsed_msec);
ResetCancelConn();
results = NULL; /* PQclear(NULL) does nothing */
}
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:
/*
* Do nothing if they are messing with savepoints themselves:
* If the user did RELEASE or ROLLBACK, our savepoint is gone.
* If they issued a SAVEPOINT, releasing ours would remove
* theirs.
*/
if (results &&
(strcmp(PQcmdStatus(results), "SAVEPOINT") == 0 ||
strcmp(PQcmdStatus(results), "RELEASE") == 0 ||
strcmp(PQcmdStatus(results), "ROLLBACK") == 0))
svptcmd = NULL;
else
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;
PQclear(results);
ResetCancelConn();
goto sendquery_cleanup;
}
PQclear(svptres);
}
}
ClearOrSaveResult(results);
/* Possible microtiming output */
if (pset.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:
/* reset \g's output-to-filename trigger */
if (pset.gfname)
{
free(pset.gfname);
pset.gfname = NULL;
}
/* reset \gx's expanded-mode flag */
pset.g_expanded = 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)
{
PGresult *results;
bool OK;
instr_time before,
after;
*elapsed_msec = 0;
if (pset.timing)
INSTR_TIME_SET_CURRENT(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.)
*/
results = PQprepare(pset.db, "", query, 0, NULL);
if (PQresultStatus(results) != PGRES_COMMAND_OK)
{
pg_log_info("%s", PQerrorMessage(pset.db));
SetResultVariables(results, false);
ClearOrSaveResult(results);
return false;
}
PQclear(results);
results = PQdescribePrepared(pset.db, "");
OK = AcceptResult(results) &&
(PQresultStatus(results) == PGRES_COMMAND_OK);
if (OK && results)
{
if (PQnfields(results) > 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(results); i++)
{
const char *name;
char *escname;
if (i > 0)
appendPQExpBufferStr(&buf, ",");
name = PQfname(results, i);
escname = PQescapeLiteral(pset.db, name, strlen(name));
if (escname == NULL)
{
pg_log_info("%s", PQerrorMessage(pset.db));
PQclear(results);
termPQExpBuffer(&buf);
return false;
}
appendPQExpBuffer(&buf, "(%s, '%u'::pg_catalog.oid, %d)",
escname,
PQftype(results, i),
PQfmod(results, i));
PQfreemem(escname);
}
appendPQExpBufferStr(&buf, ") s(name, tp, tpm)");
PQclear(results);
results = PQexec(pset.db, buf.data);
OK = AcceptResult(results);
if (pset.timing)
{
INSTR_TIME_SET_CURRENT(after);
INSTR_TIME_SUBTRACT(after, before);
*elapsed_msec += INSTR_TIME_GET_MILLISEC(after);
}
if (OK && results)
OK = PrintQueryResults(results);
termPQExpBuffer(&buf);
}
else
fprintf(pset.queryFout,
_("The command has no result, or the result has no columns.\n"));
}
SetResultVariables(results, OK);
ClearOrSaveResult(results);
return OK;
}
/*
* ExecQueryUsingCursor: run a SELECT-like query using a cursor
*
* This feature allows result sets larger than RAM to be dealt with.
*
* Returns true if the query executed successfully, false otherwise.
*
* If pset.timing is on, total query time (exclusive of result-printing) is
* stored into *elapsed_msec.
*/
static bool
ExecQueryUsingCursor(const char *query, double *elapsed_msec)
{
bool OK = true;
PGresult *results;
PQExpBufferData buf;
printQueryOpt my_popt = pset.popt;
FILE *fout;
bool is_pipe;
bool is_pager = false;
bool started_txn = false;
int64 total_tuples = 0;
int ntuples;
int fetch_count;
char fetch_cmd[64];
instr_time before,
after;
int flush_error;
*elapsed_msec = 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;
if (pset.timing)
INSTR_TIME_SET_CURRENT(before);
/* if we're not in a transaction, start one */
if (PQtransactionStatus(pset.db) == PQTRANS_IDLE)
{
results = PQexec(pset.db, "BEGIN");
OK = AcceptResult(results) &&
(PQresultStatus(results) == PGRES_COMMAND_OK);
ClearOrSaveResult(results);
if (!OK)
return false;
started_txn = true;
}
/* Send DECLARE CURSOR */
initPQExpBuffer(&buf);
appendPQExpBuffer(&buf, "DECLARE _psql_cursor NO SCROLL CURSOR FOR\n%s",
query);
results = PQexec(pset.db, buf.data);
OK = AcceptResult(results) &&
(PQresultStatus(results) == PGRES_COMMAND_OK);
if (!OK)
SetResultVariables(results, OK);
ClearOrSaveResult(results);
termPQExpBuffer(&buf);
if (!OK)
goto cleanup;
if (pset.timing)
{
INSTR_TIME_SET_CURRENT(after);
INSTR_TIME_SUBTRACT(after, before);
*elapsed_msec += INSTR_TIME_GET_MILLISEC(after);
}
/*
* In \gset mode, we force the fetch count to be 2, so that we will throw
* the appropriate error if the query returns more than one row.
*/
if (pset.gset_prefix)
fetch_count = 2;
else
fetch_count = pset.fetch_count;
snprintf(fetch_cmd, sizeof(fetch_cmd),
"FETCH FORWARD %d FROM _psql_cursor",
fetch_count);
/* one-shot expanded output requested via \gx */
if (pset.g_expanded)
my_popt.topt.expanded = 1;
/* prepare to write output to \g argument, if any */
if (pset.gfname)
{
if (!openQueryOutputFile(pset.gfname, &fout, &is_pipe))
{
OK = false;
goto cleanup;
}
if (is_pipe)
disable_sigpipe_trap();
}
else
{
fout = pset.queryFout;
is_pipe = false; /* doesn't matter */
}
/* clear any pre-existing error indication on the output stream */
clearerr(fout);
for (;;)
{
if (pset.timing)
INSTR_TIME_SET_CURRENT(before);
/* get fetch_count tuples at a time */
results = PQexec(pset.db, fetch_cmd);
if (pset.timing)
{
INSTR_TIME_SET_CURRENT(after);
INSTR_TIME_SUBTRACT(after, before);
*elapsed_msec += INSTR_TIME_GET_MILLISEC(after);
}
if (PQresultStatus(results) != PGRES_TUPLES_OK)
{
/* shut down pager before printing error message */
if (is_pager)
{
ClosePager(fout);
is_pager = false;
}
OK = AcceptResult(results);
Assert(!OK);
SetResultVariables(results, OK);
ClearOrSaveResult(results);
break;
}
if (pset.gset_prefix)
{
/* StoreQueryTuple will complain if not exactly one row */
OK = StoreQueryTuple(results);
ClearOrSaveResult(results);
break;
}
/*
* Note we do not deal with \gdesc, \gexec or \crosstabview modes here
*/
ntuples = PQntuples(results);
total_tuples += ntuples;
if (ntuples < fetch_count)
{
/* this is the last result set, so allow footer decoration */
my_popt.topt.stop_table = true;
}
else if (fout == stdout && !is_pager)
{
/*
* If query requires multiple result sets, hack to ensure that
* only one pager instance is used for the whole mess
*/
fout = PageOutput(INT_MAX, &(my_popt.topt));
is_pager = true;
}
printQuery(results, &my_popt, fout, is_pager, pset.logfile);
ClearOrSaveResult(results);
/* after the first result set, disallow header decoration */
my_popt.topt.start_table = false;
my_popt.topt.prior_records += ntuples;
/*
* Make sure to flush the output stream, so intermediate results are
* visible to the client immediately. We check the results because if
* the pager dies/exits/etc, there's no sense throwing more data at
* it.
*/
flush_error = fflush(fout);
/*
* Check if we are at the end, if a cancel was pressed, or if there
* were any errors either trying to flush out the results, or more
* generally on the output stream at all. If we hit any errors
* writing things to the stream, we presume $PAGER has disappeared and
* stop bothering to pull down more data.
*/
if (ntuples < fetch_count || cancel_pressed || flush_error ||
ferror(fout))
break;
}
if (pset.gfname)
{
/* close \g argument file/pipe */
if (is_pipe)
{
pclose(fout);
restore_sigpipe_trap();
}
else
fclose(fout);
}
else if (is_pager)
{
/* close transient pager */
ClosePager(fout);
}
if (OK)
{
/*
* We don't have a PGresult here, and even if we did it wouldn't have
* the right row count, so fake SetResultVariables(). In error cases,
* we already set the result variables above.
*/
char buf[32];
SetVariable(pset.vars, "ERROR", "false");
SetVariable(pset.vars, "SQLSTATE", "00000");
snprintf(buf, sizeof(buf), INT64_FORMAT, total_tuples);
SetVariable(pset.vars, "ROW_COUNT", buf);
}
cleanup:
if (pset.timing)
INSTR_TIME_SET_CURRENT(before);
/*
* We try to close the cursor on either success or failure, but on failure
* ignore the result (it's probably just a bleat about being in an aborted
* transaction)
*/
results = PQexec(pset.db, "CLOSE _psql_cursor");
if (OK)
{
OK = AcceptResult(results) &&
(PQresultStatus(results) == PGRES_COMMAND_OK);
ClearOrSaveResult(results);
}
else
PQclear(results);
if (started_txn)
{
results = PQexec(pset.db, OK ? "COMMIT" : "ROLLBACK");
OK &= AcceptResult(results) &&
(PQresultStatus(results) == PGRES_COMMAND_OK);
ClearOrSaveResult(results);
}
if (pset.timing)
{
INSTR_TIME_SET_CURRENT(after);
INSTR_TIME_SUBTRACT(after, before);
*elapsed_msec += INSTR_TIME_GET_MILLISEC(after);
}
return OK;
}
/*
* 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 = PQmblen(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 += PQmblen(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 += PQmblen(&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 += PQmblen(&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 += PQmblen(&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 += PQmblen(&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 += PQmblen(&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 += PQmblen(&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 += PQmblen(&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 += PQmblen(&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 += PQmblen(&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 += PQmblen(&query[wordlen], pset.encoding);
if (wordlen == 3 && pg_strncasecmp(query, "all", 3) == 0)
return true;
return false;
}
return false;
}
/*
* Check whether the specified command is a SELECT (or VALUES).
*/
static bool
is_select_command(const char *query)
{
int wordlen;
/*
* First advance over any whitespace, comments and left parentheses.
*/
for (;;)
{
query = skip_white_space(query);
if (query[0] == '(')
query++;
else
break;
}
/*
* Check word length (since "selectx" is not "select").
*/
wordlen = 0;
while (isalpha((unsigned char) query[wordlen]))
wordlen += PQmblen(&query[wordlen], pset.encoding);
if (wordlen == 6 && pg_strncasecmp(query, "select", 6) == 0)
return true;
if (wordlen == 6 && pg_strncasecmp(query, "values", 6) == 0)
return true;
return false;
}
/*
* Test if the current user is a database superuser.
*
* Note: this will correctly detect superuserness only with a protocol-3.0
* or newer backend; otherwise it will always say "false".
*/
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.
*
* Note: With a pre-protocol-3.0 connection this will always say "false",
* which should be the right answer.
*/
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.
*
* Note: this will correctly detect the session user only with a
* protocol-3.0 or newer backend; otherwise it will return the
* connection user.
*/
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
return;
}
/*
* 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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