1 /*-------------------------------------------------------------------------
2  *
3  * libpq-fe.h
4  *	  This file contains definitions for structures and
5  *	  externs for functions used by frontend postgres applications.
6  *
7  * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
8  * Portions Copyright (c) 1994, Regents of the University of California
9  *
10  * src/interfaces/libpq/libpq-fe.h
11  *
12  *-------------------------------------------------------------------------
13  */
14 
15 #ifndef LIBPQ_FE_H
16 #define LIBPQ_FE_H
17 
18 #ifdef __cplusplus
19 extern "C"
20 {
21 #endif
22 
23 #include <stdio.h>
24 
25 /*
26  * postgres_ext.h defines the backend's externally visible types,
27  * such as Oid.
28  */
29 #include "postgres_ext.h"
30 
31 /*
32  * These symbols may be used in compile-time #ifdef tests for the availability
33  * of newer libpq features.
34  */
35 /* Indicates presence of PQenterPipelineMode and friends */
36 #define LIBPQ_HAS_PIPELINING 1
37 /* Indicates presence of PQsetTraceFlags; also new PQtrace output format */
38 #define LIBPQ_HAS_TRACE_FLAGS 1
39 
40 /*
41  * Option flags for PQcopyResult
42  */
43 #define PG_COPYRES_ATTRS		  0x01
44 #define PG_COPYRES_TUPLES		  0x02	/* Implies PG_COPYRES_ATTRS */
45 #define PG_COPYRES_EVENTS		  0x04
46 #define PG_COPYRES_NOTICEHOOKS	  0x08
47 
48 /* Application-visible enum types */
49 
50 /*
51  * Although it is okay to add to these lists, values which become unused
52  * should never be removed, nor should constants be redefined - that would
53  * break compatibility with existing code.
54  */
55 
56 typedef enum
57 {
58 	CONNECTION_OK,
59 	CONNECTION_BAD,
60 	/* Non-blocking mode only below here */
61 
62 	/*
63 	 * The existence of these should never be relied upon - they should only
64 	 * be used for user feedback or similar purposes.
65 	 */
66 	CONNECTION_STARTED,			/* Waiting for connection to be made.  */
67 	CONNECTION_MADE,			/* Connection OK; waiting to send.     */
68 	CONNECTION_AWAITING_RESPONSE,	/* Waiting for a response from the
69 									 * postmaster.        */
70 	CONNECTION_AUTH_OK,			/* Received authentication; waiting for
71 								 * backend startup. */
72 	CONNECTION_SETENV,			/* This state is no longer used. */
73 	CONNECTION_SSL_STARTUP,		/* Negotiating SSL. */
74 	CONNECTION_NEEDED,			/* Internal state: connect() needed */
75 	CONNECTION_CHECK_WRITABLE,	/* Checking if session is read-write. */
76 	CONNECTION_CONSUME,			/* Consuming any extra messages. */
77 	CONNECTION_GSS_STARTUP,		/* Negotiating GSSAPI. */
78 	CONNECTION_CHECK_TARGET,	/* Checking target server properties. */
79 	CONNECTION_CHECK_STANDBY	/* Checking if server is in standby mode. */
80 } ConnStatusType;
81 
82 typedef enum
83 {
84 	PGRES_POLLING_FAILED = 0,
85 	PGRES_POLLING_READING,		/* These two indicate that one may	  */
86 	PGRES_POLLING_WRITING,		/* use select before polling again.   */
87 	PGRES_POLLING_OK,
88 	PGRES_POLLING_ACTIVE		/* unused; keep for awhile for backwards
89 								 * compatibility */
90 } PostgresPollingStatusType;
91 
92 typedef enum
93 {
94 	PGRES_EMPTY_QUERY = 0,		/* empty query string was executed */
95 	PGRES_COMMAND_OK,			/* a query command that doesn't return
96 								 * anything was executed properly by the
97 								 * backend */
98 	PGRES_TUPLES_OK,			/* a query command that returns tuples was
99 								 * executed properly by the backend, PGresult
100 								 * contains the result tuples */
101 	PGRES_COPY_OUT,				/* Copy Out data transfer in progress */
102 	PGRES_COPY_IN,				/* Copy In data transfer in progress */
103 	PGRES_BAD_RESPONSE,			/* an unexpected response was recv'd from the
104 								 * backend */
105 	PGRES_NONFATAL_ERROR,		/* notice or warning message */
106 	PGRES_FATAL_ERROR,			/* query failed */
107 	PGRES_COPY_BOTH,			/* Copy In/Out data transfer in progress */
108 	PGRES_SINGLE_TUPLE,			/* single tuple from larger resultset */
109 	PGRES_PIPELINE_SYNC,		/* pipeline synchronization point */
110 	PGRES_PIPELINE_ABORTED		/* Command didn't run because of an abort
111 								 * earlier in a pipeline */
112 } ExecStatusType;
113 
114 typedef enum
115 {
116 	PQTRANS_IDLE,				/* connection idle */
117 	PQTRANS_ACTIVE,				/* command in progress */
118 	PQTRANS_INTRANS,			/* idle, within transaction block */
119 	PQTRANS_INERROR,			/* idle, within failed transaction */
120 	PQTRANS_UNKNOWN				/* cannot determine status */
121 } PGTransactionStatusType;
122 
123 typedef enum
124 {
125 	PQERRORS_TERSE,				/* single-line error messages */
126 	PQERRORS_DEFAULT,			/* recommended style */
127 	PQERRORS_VERBOSE,			/* all the facts, ma'am */
128 	PQERRORS_SQLSTATE			/* only error severity and SQLSTATE code */
129 } PGVerbosity;
130 
131 typedef enum
132 {
133 	PQSHOW_CONTEXT_NEVER,		/* never show CONTEXT field */
134 	PQSHOW_CONTEXT_ERRORS,		/* show CONTEXT for errors only (default) */
135 	PQSHOW_CONTEXT_ALWAYS		/* always show CONTEXT field */
136 } PGContextVisibility;
137 
138 /*
139  * PGPing - The ordering of this enum should not be altered because the
140  * values are exposed externally via pg_isready.
141  */
142 
143 typedef enum
144 {
145 	PQPING_OK,					/* server is accepting connections */
146 	PQPING_REJECT,				/* server is alive but rejecting connections */
147 	PQPING_NO_RESPONSE,			/* could not establish connection */
148 	PQPING_NO_ATTEMPT			/* connection not attempted (bad params) */
149 } PGPing;
150 
151 /*
152  * PGpipelineStatus - Current status of pipeline mode
153  */
154 typedef enum
155 {
156 	PQ_PIPELINE_OFF,
157 	PQ_PIPELINE_ON,
158 	PQ_PIPELINE_ABORTED
159 } PGpipelineStatus;
160 
161 /* PGconn encapsulates a connection to the backend.
162  * The contents of this struct are not supposed to be known to applications.
163  */
164 typedef struct pg_conn PGconn;
165 
166 /* PGresult encapsulates the result of a query (or more precisely, of a single
167  * SQL command --- a query string given to PQsendQuery can contain multiple
168  * commands and thus return multiple PGresult objects).
169  * The contents of this struct are not supposed to be known to applications.
170  */
171 typedef struct pg_result PGresult;
172 
173 /* PGcancel encapsulates the information needed to cancel a running
174  * query on an existing connection.
175  * The contents of this struct are not supposed to be known to applications.
176  */
177 typedef struct pg_cancel PGcancel;
178 
179 /* PGnotify represents the occurrence of a NOTIFY message.
180  * Ideally this would be an opaque typedef, but it's so simple that it's
181  * unlikely to change.
182  * NOTE: in Postgres 6.4 and later, the be_pid is the notifying backend's,
183  * whereas in earlier versions it was always your own backend's PID.
184  */
185 typedef struct pgNotify
186 {
187 	char	   *relname;		/* notification condition name */
188 	int			be_pid;			/* process ID of notifying server process */
189 	char	   *extra;			/* notification parameter */
190 	/* Fields below here are private to libpq; apps should not use 'em */
191 	struct pgNotify *next;		/* list link */
192 } PGnotify;
193 
194 /* Function types for notice-handling callbacks */
195 typedef void (*PQnoticeReceiver) (void *arg, const PGresult *res);
196 typedef void (*PQnoticeProcessor) (void *arg, const char *message);
197 
198 /* Print options for PQprint() */
199 typedef char pqbool;
200 
201 typedef struct _PQprintOpt
202 {
203 	pqbool		header;			/* print output field headings and row count */
204 	pqbool		align;			/* fill align the fields */
205 	pqbool		standard;		/* old brain dead format */
206 	pqbool		html3;			/* output html tables */
207 	pqbool		expanded;		/* expand tables */
208 	pqbool		pager;			/* use pager for output if needed */
209 	char	   *fieldSep;		/* field separator */
210 	char	   *tableOpt;		/* insert to HTML <table ...> */
211 	char	   *caption;		/* HTML <caption> */
212 	char	  **fieldName;		/* null terminated array of replacement field
213 								 * names */
214 } PQprintOpt;
215 
216 /* ----------------
217  * Structure for the conninfo parameter definitions returned by PQconndefaults
218  * or PQconninfoParse.
219  *
220  * All fields except "val" point at static strings which must not be altered.
221  * "val" is either NULL or a malloc'd current-value string.  PQconninfoFree()
222  * will release both the val strings and the PQconninfoOption array itself.
223  * ----------------
224  */
225 typedef struct _PQconninfoOption
226 {
227 	char	   *keyword;		/* The keyword of the option			*/
228 	char	   *envvar;			/* Fallback environment variable name	*/
229 	char	   *compiled;		/* Fallback compiled in default value	*/
230 	char	   *val;			/* Option's current value, or NULL		 */
231 	char	   *label;			/* Label for field in connect dialog	*/
232 	char	   *dispchar;		/* Indicates how to display this field in a
233 								 * connect dialog. Values are: "" Display
234 								 * entered value as is "*" Password field -
235 								 * hide value "D"  Debug option - don't show
236 								 * by default */
237 	int			dispsize;		/* Field size in characters for dialog	*/
238 } PQconninfoOption;
239 
240 /* ----------------
241  * PQArgBlock -- structure for PQfn() arguments
242  * ----------------
243  */
244 typedef struct
245 {
246 	int			len;
247 	int			isint;
248 	union
249 	{
250 		int		   *ptr;		/* can't use void (dec compiler barfs)	 */
251 		int			integer;
252 	}			u;
253 } PQArgBlock;
254 
255 /* ----------------
256  * PGresAttDesc -- Data about a single attribute (column) of a query result
257  * ----------------
258  */
259 typedef struct pgresAttDesc
260 {
261 	char	   *name;			/* column name */
262 	Oid			tableid;		/* source table, if known */
263 	int			columnid;		/* source column, if known */
264 	int			format;			/* format code for value (text/binary) */
265 	Oid			typid;			/* type id */
266 	int			typlen;			/* type size */
267 	int			atttypmod;		/* type-specific modifier info */
268 } PGresAttDesc;
269 
270 /* ----------------
271  * Exported functions of libpq
272  * ----------------
273  */
274 
275 /* === in fe-connect.c === */
276 
277 /* make a new client connection to the backend */
278 /* Asynchronous (non-blocking) */
279 extern PGconn *PQconnectStart(const char *conninfo);
280 extern PGconn *PQconnectStartParams(const char *const *keywords,
281 									const char *const *values, int expand_dbname);
282 extern PostgresPollingStatusType PQconnectPoll(PGconn *conn);
283 
284 /* Synchronous (blocking) */
285 extern PGconn *PQconnectdb(const char *conninfo);
286 extern PGconn *PQconnectdbParams(const char *const *keywords,
287 								 const char *const *values, int expand_dbname);
288 extern PGconn *PQsetdbLogin(const char *pghost, const char *pgport,
289 							const char *pgoptions, const char *pgtty,
290 							const char *dbName,
291 							const char *login, const char *pwd);
292 
293 #define PQsetdb(M_PGHOST,M_PGPORT,M_PGOPT,M_PGTTY,M_DBNAME)  \
294 	PQsetdbLogin(M_PGHOST, M_PGPORT, M_PGOPT, M_PGTTY, M_DBNAME, NULL, NULL)
295 
296 /* close the current connection and free the PGconn data structure */
297 extern void PQfinish(PGconn *conn);
298 
299 /* get info about connection options known to PQconnectdb */
300 extern PQconninfoOption *PQconndefaults(void);
301 
302 /* parse connection options in same way as PQconnectdb */
303 extern PQconninfoOption *PQconninfoParse(const char *conninfo, char **errmsg);
304 
305 /* return the connection options used by a live connection */
306 extern PQconninfoOption *PQconninfo(PGconn *conn);
307 
308 /* free the data structure returned by PQconndefaults() or PQconninfoParse() */
309 extern void PQconninfoFree(PQconninfoOption *connOptions);
310 
311 /*
312  * close the current connection and reestablish a new one with the same
313  * parameters
314  */
315 /* Asynchronous (non-blocking) */
316 extern int	PQresetStart(PGconn *conn);
317 extern PostgresPollingStatusType PQresetPoll(PGconn *conn);
318 
319 /* Synchronous (blocking) */
320 extern void PQreset(PGconn *conn);
321 
322 /* request a cancel structure */
323 extern PGcancel *PQgetCancel(PGconn *conn);
324 
325 /* free a cancel structure */
326 extern void PQfreeCancel(PGcancel *cancel);
327 
328 /* issue a cancel request */
329 extern int	PQcancel(PGcancel *cancel, char *errbuf, int errbufsize);
330 
331 /* backwards compatible version of PQcancel; not thread-safe */
332 extern int	PQrequestCancel(PGconn *conn);
333 
334 /* Accessor functions for PGconn objects */
335 extern char *PQdb(const PGconn *conn);
336 extern char *PQuser(const PGconn *conn);
337 extern char *PQpass(const PGconn *conn);
338 extern char *PQhost(const PGconn *conn);
339 extern char *PQhostaddr(const PGconn *conn);
340 extern char *PQport(const PGconn *conn);
341 extern char *PQtty(const PGconn *conn);
342 extern char *PQoptions(const PGconn *conn);
343 extern ConnStatusType PQstatus(const PGconn *conn);
344 extern PGTransactionStatusType PQtransactionStatus(const PGconn *conn);
345 extern const char *PQparameterStatus(const PGconn *conn,
346 									 const char *paramName);
347 extern int	PQprotocolVersion(const PGconn *conn);
348 extern int	PQserverVersion(const PGconn *conn);
349 extern char *PQerrorMessage(const PGconn *conn);
350 extern int	PQsocket(const PGconn *conn);
351 extern int	PQbackendPID(const PGconn *conn);
352 extern PGpipelineStatus PQpipelineStatus(const PGconn *conn);
353 extern int	PQconnectionNeedsPassword(const PGconn *conn);
354 extern int	PQconnectionUsedPassword(const PGconn *conn);
355 extern int	PQclientEncoding(const PGconn *conn);
356 extern int	PQsetClientEncoding(PGconn *conn, const char *encoding);
357 
358 /* SSL information functions */
359 extern int	PQsslInUse(PGconn *conn);
360 extern void *PQsslStruct(PGconn *conn, const char *struct_name);
361 extern const char *PQsslAttribute(PGconn *conn, const char *attribute_name);
362 extern const char *const *PQsslAttributeNames(PGconn *conn);
363 
364 /* Get the OpenSSL structure associated with a connection. Returns NULL for
365  * unencrypted connections or if any other TLS library is in use. */
366 extern void *PQgetssl(PGconn *conn);
367 
368 /* Tell libpq whether it needs to initialize OpenSSL */
369 extern void PQinitSSL(int do_init);
370 
371 /* More detailed way to tell libpq whether it needs to initialize OpenSSL */
372 extern void PQinitOpenSSL(int do_ssl, int do_crypto);
373 
374 /* Return true if GSSAPI encryption is in use */
375 extern int	PQgssEncInUse(PGconn *conn);
376 
377 /* Returns GSSAPI context if GSSAPI is in use */
378 extern void *PQgetgssctx(PGconn *conn);
379 
380 /* Set verbosity for PQerrorMessage and PQresultErrorMessage */
381 extern PGVerbosity PQsetErrorVerbosity(PGconn *conn, PGVerbosity verbosity);
382 
383 /* Set CONTEXT visibility for PQerrorMessage and PQresultErrorMessage */
384 extern PGContextVisibility PQsetErrorContextVisibility(PGconn *conn,
385 													   PGContextVisibility show_context);
386 
387 /* Override default notice handling routines */
388 extern PQnoticeReceiver PQsetNoticeReceiver(PGconn *conn,
389 											PQnoticeReceiver proc,
390 											void *arg);
391 extern PQnoticeProcessor PQsetNoticeProcessor(PGconn *conn,
392 											  PQnoticeProcessor proc,
393 											  void *arg);
394 
395 /*
396  *	   Used to set callback that prevents concurrent access to
397  *	   non-thread safe functions that libpq needs.
398  *	   The default implementation uses a libpq internal mutex.
399  *	   Only required for multithreaded apps that use kerberos
400  *	   both within their app and for postgresql connections.
401  */
402 typedef void (*pgthreadlock_t) (int acquire);
403 
404 extern pgthreadlock_t PQregisterThreadLock(pgthreadlock_t newhandler);
405 
406 /* === in fe-trace.c === */
407 extern void PQtrace(PGconn *conn, FILE *debug_port);
408 extern void PQuntrace(PGconn *conn);
409 
410 /* flags controlling trace output: */
411 /* omit timestamps from each line */
412 #define PQTRACE_SUPPRESS_TIMESTAMPS		(1<<0)
413 /* redact portions of some messages, for testing frameworks */
414 #define PQTRACE_REGRESS_MODE			(1<<1)
415 extern void PQsetTraceFlags(PGconn *conn, int flags);
416 
417 /* === in fe-exec.c === */
418 
419 /* Simple synchronous query */
420 extern PGresult *PQexec(PGconn *conn, const char *query);
421 extern PGresult *PQexecParams(PGconn *conn,
422 							  const char *command,
423 							  int nParams,
424 							  const Oid *paramTypes,
425 							  const char *const *paramValues,
426 							  const int *paramLengths,
427 							  const int *paramFormats,
428 							  int resultFormat);
429 extern PGresult *PQprepare(PGconn *conn, const char *stmtName,
430 						   const char *query, int nParams,
431 						   const Oid *paramTypes);
432 extern PGresult *PQexecPrepared(PGconn *conn,
433 								const char *stmtName,
434 								int nParams,
435 								const char *const *paramValues,
436 								const int *paramLengths,
437 								const int *paramFormats,
438 								int resultFormat);
439 
440 /* Interface for multiple-result or asynchronous queries */
441 #define PQ_QUERY_PARAM_MAX_LIMIT 65535
442 
443 extern int	PQsendQuery(PGconn *conn, const char *query);
444 extern int	PQsendQueryParams(PGconn *conn,
445 							  const char *command,
446 							  int nParams,
447 							  const Oid *paramTypes,
448 							  const char *const *paramValues,
449 							  const int *paramLengths,
450 							  const int *paramFormats,
451 							  int resultFormat);
452 extern int	PQsendPrepare(PGconn *conn, const char *stmtName,
453 						  const char *query, int nParams,
454 						  const Oid *paramTypes);
455 extern int	PQsendQueryPrepared(PGconn *conn,
456 								const char *stmtName,
457 								int nParams,
458 								const char *const *paramValues,
459 								const int *paramLengths,
460 								const int *paramFormats,
461 								int resultFormat);
462 extern int	PQsetSingleRowMode(PGconn *conn);
463 extern PGresult *PQgetResult(PGconn *conn);
464 
465 /* Routines for managing an asynchronous query */
466 extern int	PQisBusy(PGconn *conn);
467 extern int	PQconsumeInput(PGconn *conn);
468 
469 /* Routines for pipeline mode management */
470 extern int	PQenterPipelineMode(PGconn *conn);
471 extern int	PQexitPipelineMode(PGconn *conn);
472 extern int	PQpipelineSync(PGconn *conn);
473 extern int	PQsendFlushRequest(PGconn *conn);
474 
475 /* LISTEN/NOTIFY support */
476 extern PGnotify *PQnotifies(PGconn *conn);
477 
478 /* Routines for copy in/out */
479 extern int	PQputCopyData(PGconn *conn, const char *buffer, int nbytes);
480 extern int	PQputCopyEnd(PGconn *conn, const char *errormsg);
481 extern int	PQgetCopyData(PGconn *conn, char **buffer, int async);
482 
483 /* Deprecated routines for copy in/out */
484 extern int	PQgetline(PGconn *conn, char *string, int length);
485 extern int	PQputline(PGconn *conn, const char *string);
486 extern int	PQgetlineAsync(PGconn *conn, char *buffer, int bufsize);
487 extern int	PQputnbytes(PGconn *conn, const char *buffer, int nbytes);
488 extern int	PQendcopy(PGconn *conn);
489 
490 /* Set blocking/nonblocking connection to the backend */
491 extern int	PQsetnonblocking(PGconn *conn, int arg);
492 extern int	PQisnonblocking(const PGconn *conn);
493 extern int	PQisthreadsafe(void);
494 extern PGPing PQping(const char *conninfo);
495 extern PGPing PQpingParams(const char *const *keywords,
496 						   const char *const *values, int expand_dbname);
497 
498 /* Force the write buffer to be written (or at least try) */
499 extern int	PQflush(PGconn *conn);
500 
501 /*
502  * "Fast path" interface --- not really recommended for application
503  * use
504  */
505 extern PGresult *PQfn(PGconn *conn,
506 					  int fnid,
507 					  int *result_buf,
508 					  int *result_len,
509 					  int result_is_int,
510 					  const PQArgBlock *args,
511 					  int nargs);
512 
513 /* Accessor functions for PGresult objects */
514 extern ExecStatusType PQresultStatus(const PGresult *res);
515 extern char *PQresStatus(ExecStatusType status);
516 extern char *PQresultErrorMessage(const PGresult *res);
517 extern char *PQresultVerboseErrorMessage(const PGresult *res,
518 										 PGVerbosity verbosity,
519 										 PGContextVisibility show_context);
520 extern char *PQresultErrorField(const PGresult *res, int fieldcode);
521 extern int	PQntuples(const PGresult *res);
522 extern int	PQnfields(const PGresult *res);
523 extern int	PQbinaryTuples(const PGresult *res);
524 extern char *PQfname(const PGresult *res, int field_num);
525 extern int	PQfnumber(const PGresult *res, const char *field_name);
526 extern Oid	PQftable(const PGresult *res, int field_num);
527 extern int	PQftablecol(const PGresult *res, int field_num);
528 extern int	PQfformat(const PGresult *res, int field_num);
529 extern Oid	PQftype(const PGresult *res, int field_num);
530 extern int	PQfsize(const PGresult *res, int field_num);
531 extern int	PQfmod(const PGresult *res, int field_num);
532 extern char *PQcmdStatus(PGresult *res);
533 extern char *PQoidStatus(const PGresult *res);	/* old and ugly */
534 extern Oid	PQoidValue(const PGresult *res);	/* new and improved */
535 extern char *PQcmdTuples(PGresult *res);
536 extern char *PQgetvalue(const PGresult *res, int tup_num, int field_num);
537 extern int	PQgetlength(const PGresult *res, int tup_num, int field_num);
538 extern int	PQgetisnull(const PGresult *res, int tup_num, int field_num);
539 extern int	PQnparams(const PGresult *res);
540 extern Oid	PQparamtype(const PGresult *res, int param_num);
541 
542 /* Describe prepared statements and portals */
543 extern PGresult *PQdescribePrepared(PGconn *conn, const char *stmt);
544 extern PGresult *PQdescribePortal(PGconn *conn, const char *portal);
545 extern int	PQsendDescribePrepared(PGconn *conn, const char *stmt);
546 extern int	PQsendDescribePortal(PGconn *conn, const char *portal);
547 
548 /* Delete a PGresult */
549 extern void PQclear(PGresult *res);
550 
551 /* For freeing other alloc'd results, such as PGnotify structs */
552 extern void PQfreemem(void *ptr);
553 
554 /* Exists for backward compatibility.  bjm 2003-03-24 */
555 #define PQfreeNotify(ptr) PQfreemem(ptr)
556 
557 /* Error when no password was given. */
558 /* Note: depending on this is deprecated; use PQconnectionNeedsPassword(). */
559 #define PQnoPasswordSupplied	"fe_sendauth: no password supplied\n"
560 
561 /* Create and manipulate PGresults */
562 extern PGresult *PQmakeEmptyPGresult(PGconn *conn, ExecStatusType status);
563 extern PGresult *PQcopyResult(const PGresult *src, int flags);
564 extern int	PQsetResultAttrs(PGresult *res, int numAttributes, PGresAttDesc *attDescs);
565 extern void *PQresultAlloc(PGresult *res, size_t nBytes);
566 extern size_t PQresultMemorySize(const PGresult *res);
567 extern int	PQsetvalue(PGresult *res, int tup_num, int field_num, char *value, int len);
568 
569 /* Quoting strings before inclusion in queries. */
570 extern size_t PQescapeStringConn(PGconn *conn,
571 								 char *to, const char *from, size_t length,
572 								 int *error);
573 extern char *PQescapeLiteral(PGconn *conn, const char *str, size_t len);
574 extern char *PQescapeIdentifier(PGconn *conn, const char *str, size_t len);
575 extern unsigned char *PQescapeByteaConn(PGconn *conn,
576 										const unsigned char *from, size_t from_length,
577 										size_t *to_length);
578 extern unsigned char *PQunescapeBytea(const unsigned char *strtext,
579 									  size_t *retbuflen);
580 
581 /* These forms are deprecated! */
582 extern size_t PQescapeString(char *to, const char *from, size_t length);
583 extern unsigned char *PQescapeBytea(const unsigned char *from, size_t from_length,
584 									size_t *to_length);
585 
586 
587 
588 /* === in fe-print.c === */
589 
590 extern void PQprint(FILE *fout, /* output stream */
591 					const PGresult *res,
592 					const PQprintOpt *ps);	/* option structure */
593 
594 /*
595  * really old printing routines
596  */
597 extern void PQdisplayTuples(const PGresult *res,
598 							FILE *fp,	/* where to send the output */
599 							int fillAlign,	/* pad the fields with spaces */
600 							const char *fieldSep,	/* field separator */
601 							int printHeader,	/* display headers? */
602 							int quiet);
603 
604 extern void PQprintTuples(const PGresult *res,
605 						  FILE *fout,	/* output stream */
606 						  int PrintAttNames,	/* print attribute names */
607 						  int TerseOutput,	/* delimiter bars */
608 						  int colWidth);	/* width of column, if 0, use
609 											 * variable width */
610 
611 
612 /* === in fe-lobj.c === */
613 
614 /* Large-object access routines */
615 extern int	lo_open(PGconn *conn, Oid lobjId, int mode);
616 extern int	lo_close(PGconn *conn, int fd);
617 extern int	lo_read(PGconn *conn, int fd, char *buf, size_t len);
618 extern int	lo_write(PGconn *conn, int fd, const char *buf, size_t len);
619 extern int	lo_lseek(PGconn *conn, int fd, int offset, int whence);
620 extern pg_int64 lo_lseek64(PGconn *conn, int fd, pg_int64 offset, int whence);
621 extern Oid	lo_creat(PGconn *conn, int mode);
622 extern Oid	lo_create(PGconn *conn, Oid lobjId);
623 extern int	lo_tell(PGconn *conn, int fd);
624 extern pg_int64 lo_tell64(PGconn *conn, int fd);
625 extern int	lo_truncate(PGconn *conn, int fd, size_t len);
626 extern int	lo_truncate64(PGconn *conn, int fd, pg_int64 len);
627 extern int	lo_unlink(PGconn *conn, Oid lobjId);
628 extern Oid	lo_import(PGconn *conn, const char *filename);
629 extern Oid	lo_import_with_oid(PGconn *conn, const char *filename, Oid lobjId);
630 extern int	lo_export(PGconn *conn, Oid lobjId, const char *filename);
631 
632 /* === in fe-misc.c === */
633 
634 /* Get the version of the libpq library in use */
635 extern int	PQlibVersion(void);
636 
637 /* Determine length of multibyte encoded char at *s */
638 extern int	PQmblen(const char *s, int encoding);
639 
640 /* Same, but not more than the distance to the end of string s */
641 extern int	PQmblenBounded(const char *s, int encoding);
642 
643 /* Determine display length of multibyte encoded char at *s */
644 extern int	PQdsplen(const char *s, int encoding);
645 
646 /* Get encoding id from environment variable PGCLIENTENCODING */
647 extern int	PQenv2encoding(void);
648 
649 /* === in fe-auth.c === */
650 
651 extern char *PQencryptPassword(const char *passwd, const char *user);
652 extern char *PQencryptPasswordConn(PGconn *conn, const char *passwd, const char *user, const char *algorithm);
653 
654 /* === in encnames.c === */
655 
656 extern int	pg_char_to_encoding(const char *name);
657 extern const char *pg_encoding_to_char(int encoding);
658 extern int	pg_valid_server_encoding_id(int encoding);
659 
660 /* === in fe-secure-openssl.c === */
661 
662 /* Support for overriding sslpassword handling with a callback */
663 typedef int (*PQsslKeyPassHook_OpenSSL_type) (char *buf, int size, PGconn *conn);
664 extern PQsslKeyPassHook_OpenSSL_type PQgetSSLKeyPassHook_OpenSSL(void);
665 extern void PQsetSSLKeyPassHook_OpenSSL(PQsslKeyPassHook_OpenSSL_type hook);
666 extern int	PQdefaultSSLKeyPassHook_OpenSSL(char *buf, int size, PGconn *conn);
667 
668 #ifdef __cplusplus
669 }
670 #endif
671 
672 #endif							/* LIBPQ_FE_H */
673