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) 1996-2019, 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  * Option flags for PQcopyResult
33  */
34 #define PG_COPYRES_ATTRS		  0x01
35 #define PG_COPYRES_TUPLES		  0x02	/* Implies PG_COPYRES_ATTRS */
36 #define PG_COPYRES_EVENTS		  0x04
37 #define PG_COPYRES_NOTICEHOOKS	  0x08
38 
39 /* Application-visible enum types */
40 
41 /*
42  * Although it is okay to add to these lists, values which become unused
43  * should never be removed, nor should constants be redefined - that would
44  * break compatibility with existing code.
45  */
46 
47 typedef enum
48 {
49 	CONNECTION_OK,
50 	CONNECTION_BAD,
51 	/* Non-blocking mode only below here */
52 
53 	/*
54 	 * The existence of these should never be relied upon - they should only
55 	 * be used for user feedback or similar purposes.
56 	 */
57 	CONNECTION_STARTED,			/* Waiting for connection to be made.  */
58 	CONNECTION_MADE,			/* Connection OK; waiting to send.     */
59 	CONNECTION_AWAITING_RESPONSE,	/* Waiting for a response from the
60 									 * postmaster.        */
61 	CONNECTION_AUTH_OK,			/* Received authentication; waiting for
62 								 * backend startup. */
63 	CONNECTION_SETENV,			/* Negotiating environment. */
64 	CONNECTION_SSL_STARTUP,		/* Negotiating SSL. */
65 	CONNECTION_NEEDED,			/* Internal state: connect() needed */
66 	CONNECTION_CHECK_WRITABLE,	/* Check if we could make a writable
67 								 * connection. */
68 	CONNECTION_CONSUME,			/* Wait for any pending message and consume
69 								 * them. */
70 	CONNECTION_GSS_STARTUP		/* Negotiating GSSAPI. */
71 } ConnStatusType;
72 
73 typedef enum
74 {
75 	PGRES_POLLING_FAILED = 0,
76 	PGRES_POLLING_READING,		/* These two indicate that one may	  */
77 	PGRES_POLLING_WRITING,		/* use select before polling again.   */
78 	PGRES_POLLING_OK,
79 	PGRES_POLLING_ACTIVE		/* unused; keep for awhile for backwards
80 								 * compatibility */
81 } PostgresPollingStatusType;
82 
83 typedef enum
84 {
85 	PGRES_EMPTY_QUERY = 0,		/* empty query string was executed */
86 	PGRES_COMMAND_OK,			/* a query command that doesn't return
87 								 * anything was executed properly by the
88 								 * backend */
89 	PGRES_TUPLES_OK,			/* a query command that returns tuples was
90 								 * executed properly by the backend, PGresult
91 								 * contains the result tuples */
92 	PGRES_COPY_OUT,				/* Copy Out data transfer in progress */
93 	PGRES_COPY_IN,				/* Copy In data transfer in progress */
94 	PGRES_BAD_RESPONSE,			/* an unexpected response was recv'd from the
95 								 * backend */
96 	PGRES_NONFATAL_ERROR,		/* notice or warning message */
97 	PGRES_FATAL_ERROR,			/* query failed */
98 	PGRES_COPY_BOTH,			/* Copy In/Out data transfer in progress */
99 	PGRES_SINGLE_TUPLE			/* single tuple from larger resultset */
100 } ExecStatusType;
101 
102 typedef enum
103 {
104 	PQTRANS_IDLE,				/* connection idle */
105 	PQTRANS_ACTIVE,				/* command in progress */
106 	PQTRANS_INTRANS,			/* idle, within transaction block */
107 	PQTRANS_INERROR,			/* idle, within failed transaction */
108 	PQTRANS_UNKNOWN				/* cannot determine status */
109 } PGTransactionStatusType;
110 
111 typedef enum
112 {
113 	PQERRORS_TERSE,				/* single-line error messages */
114 	PQERRORS_DEFAULT,			/* recommended style */
115 	PQERRORS_VERBOSE,			/* all the facts, ma'am */
116 	PQERRORS_SQLSTATE			/* only error severity and SQLSTATE code */
117 } PGVerbosity;
118 
119 typedef enum
120 {
121 	PQSHOW_CONTEXT_NEVER,		/* never show CONTEXT field */
122 	PQSHOW_CONTEXT_ERRORS,		/* show CONTEXT for errors only (default) */
123 	PQSHOW_CONTEXT_ALWAYS		/* always show CONTEXT field */
124 } PGContextVisibility;
125 
126 /*
127  * PGPing - The ordering of this enum should not be altered because the
128  * values are exposed externally via pg_isready.
129  */
130 
131 typedef enum
132 {
133 	PQPING_OK,					/* server is accepting connections */
134 	PQPING_REJECT,				/* server is alive but rejecting connections */
135 	PQPING_NO_RESPONSE,			/* could not establish connection */
136 	PQPING_NO_ATTEMPT			/* connection not attempted (bad params) */
137 } PGPing;
138 
139 /* PGconn encapsulates a connection to the backend.
140  * The contents of this struct are not supposed to be known to applications.
141  */
142 typedef struct pg_conn PGconn;
143 
144 /* PGresult encapsulates the result of a query (or more precisely, of a single
145  * SQL command --- a query string given to PQsendQuery can contain multiple
146  * commands and thus return multiple PGresult objects).
147  * The contents of this struct are not supposed to be known to applications.
148  */
149 typedef struct pg_result PGresult;
150 
151 /* PGcancel encapsulates the information needed to cancel a running
152  * query on an existing connection.
153  * The contents of this struct are not supposed to be known to applications.
154  */
155 typedef struct pg_cancel PGcancel;
156 
157 /* PGnotify represents the occurrence of a NOTIFY message.
158  * Ideally this would be an opaque typedef, but it's so simple that it's
159  * unlikely to change.
160  * NOTE: in Postgres 6.4 and later, the be_pid is the notifying backend's,
161  * whereas in earlier versions it was always your own backend's PID.
162  */
163 typedef struct pgNotify
164 {
165 	char	   *relname;		/* notification condition name */
166 	int			be_pid;			/* process ID of notifying server process */
167 	char	   *extra;			/* notification parameter */
168 	/* Fields below here are private to libpq; apps should not use 'em */
169 	struct pgNotify *next;		/* list link */
170 } PGnotify;
171 
172 /* Function types for notice-handling callbacks */
173 typedef void (*PQnoticeReceiver) (void *arg, const PGresult *res);
174 typedef void (*PQnoticeProcessor) (void *arg, const char *message);
175 
176 /* Print options for PQprint() */
177 typedef char pqbool;
178 
179 typedef struct _PQprintOpt
180 {
181 	pqbool		header;			/* print output field headings and row count */
182 	pqbool		align;			/* fill align the fields */
183 	pqbool		standard;		/* old brain dead format */
184 	pqbool		html3;			/* output html tables */
185 	pqbool		expanded;		/* expand tables */
186 	pqbool		pager;			/* use pager for output if needed */
187 	char	   *fieldSep;		/* field separator */
188 	char	   *tableOpt;		/* insert to HTML <table ...> */
189 	char	   *caption;		/* HTML <caption> */
190 	char	  **fieldName;		/* null terminated array of replacement field
191 								 * names */
192 } PQprintOpt;
193 
194 /* ----------------
195  * Structure for the conninfo parameter definitions returned by PQconndefaults
196  * or PQconninfoParse.
197  *
198  * All fields except "val" point at static strings which must not be altered.
199  * "val" is either NULL or a malloc'd current-value string.  PQconninfoFree()
200  * will release both the val strings and the PQconninfoOption array itself.
201  * ----------------
202  */
203 typedef struct _PQconninfoOption
204 {
205 	char	   *keyword;		/* The keyword of the option			*/
206 	char	   *envvar;			/* Fallback environment variable name	*/
207 	char	   *compiled;		/* Fallback compiled in default value	*/
208 	char	   *val;			/* Option's current value, or NULL		 */
209 	char	   *label;			/* Label for field in connect dialog	*/
210 	char	   *dispchar;		/* Indicates how to display this field in a
211 								 * connect dialog. Values are: "" Display
212 								 * entered value as is "*" Password field -
213 								 * hide value "D"  Debug option - don't show
214 								 * by default */
215 	int			dispsize;		/* Field size in characters for dialog	*/
216 } PQconninfoOption;
217 
218 /* ----------------
219  * PQArgBlock -- structure for PQfn() arguments
220  * ----------------
221  */
222 typedef struct
223 {
224 	int			len;
225 	int			isint;
226 	union
227 	{
228 		int		   *ptr;		/* can't use void (dec compiler barfs)	 */
229 		int			integer;
230 	}			u;
231 } PQArgBlock;
232 
233 /* ----------------
234  * PGresAttDesc -- Data about a single attribute (column) of a query result
235  * ----------------
236  */
237 typedef struct pgresAttDesc
238 {
239 	char	   *name;			/* column name */
240 	Oid			tableid;		/* source table, if known */
241 	int			columnid;		/* source column, if known */
242 	int			format;			/* format code for value (text/binary) */
243 	Oid			typid;			/* type id */
244 	int			typlen;			/* type size */
245 	int			atttypmod;		/* type-specific modifier info */
246 } PGresAttDesc;
247 
248 /* ----------------
249  * Exported functions of libpq
250  * ----------------
251  */
252 
253 /* ===	in fe-connect.c === */
254 
255 /* make a new client connection to the backend */
256 /* Asynchronous (non-blocking) */
257 extern PGconn *PQconnectStart(const char *conninfo);
258 extern PGconn *PQconnectStartParams(const char *const *keywords,
259 									const char *const *values, int expand_dbname);
260 extern PostgresPollingStatusType PQconnectPoll(PGconn *conn);
261 
262 /* Synchronous (blocking) */
263 extern PGconn *PQconnectdb(const char *conninfo);
264 extern PGconn *PQconnectdbParams(const char *const *keywords,
265 								 const char *const *values, int expand_dbname);
266 extern PGconn *PQsetdbLogin(const char *pghost, const char *pgport,
267 							const char *pgoptions, const char *pgtty,
268 							const char *dbName,
269 							const char *login, const char *pwd);
270 
271 #define PQsetdb(M_PGHOST,M_PGPORT,M_PGOPT,M_PGTTY,M_DBNAME)  \
272 	PQsetdbLogin(M_PGHOST, M_PGPORT, M_PGOPT, M_PGTTY, M_DBNAME, NULL, NULL)
273 
274 /* close the current connection and free the PGconn data structure */
275 extern void PQfinish(PGconn *conn);
276 
277 /* get info about connection options known to PQconnectdb */
278 extern PQconninfoOption *PQconndefaults(void);
279 
280 /* parse connection options in same way as PQconnectdb */
281 extern PQconninfoOption *PQconninfoParse(const char *conninfo, char **errmsg);
282 
283 /* return the connection options used by a live connection */
284 extern PQconninfoOption *PQconninfo(PGconn *conn);
285 
286 /* free the data structure returned by PQconndefaults() or PQconninfoParse() */
287 extern void PQconninfoFree(PQconninfoOption *connOptions);
288 
289 /*
290  * close the current connection and restablish a new one with the same
291  * parameters
292  */
293 /* Asynchronous (non-blocking) */
294 extern int	PQresetStart(PGconn *conn);
295 extern PostgresPollingStatusType PQresetPoll(PGconn *conn);
296 
297 /* Synchronous (blocking) */
298 extern void PQreset(PGconn *conn);
299 
300 /* request a cancel structure */
301 extern PGcancel *PQgetCancel(PGconn *conn);
302 
303 /* free a cancel structure */
304 extern void PQfreeCancel(PGcancel *cancel);
305 
306 /* issue a cancel request */
307 extern int	PQcancel(PGcancel *cancel, char *errbuf, int errbufsize);
308 
309 /* backwards compatible version of PQcancel; not thread-safe */
310 extern int	PQrequestCancel(PGconn *conn);
311 
312 /* Accessor functions for PGconn objects */
313 extern char *PQdb(const PGconn *conn);
314 extern char *PQuser(const PGconn *conn);
315 extern char *PQpass(const PGconn *conn);
316 extern char *PQhost(const PGconn *conn);
317 extern char *PQhostaddr(const PGconn *conn);
318 extern char *PQport(const PGconn *conn);
319 extern char *PQtty(const PGconn *conn);
320 extern char *PQoptions(const PGconn *conn);
321 extern ConnStatusType PQstatus(const PGconn *conn);
322 extern PGTransactionStatusType PQtransactionStatus(const PGconn *conn);
323 extern const char *PQparameterStatus(const PGconn *conn,
324 									 const char *paramName);
325 extern int	PQprotocolVersion(const PGconn *conn);
326 extern int	PQserverVersion(const PGconn *conn);
327 extern char *PQerrorMessage(const PGconn *conn);
328 extern int	PQsocket(const PGconn *conn);
329 extern int	PQbackendPID(const PGconn *conn);
330 extern int	PQconnectionNeedsPassword(const PGconn *conn);
331 extern int	PQconnectionUsedPassword(const PGconn *conn);
332 extern int	PQclientEncoding(const PGconn *conn);
333 extern int	PQsetClientEncoding(PGconn *conn, const char *encoding);
334 
335 /* SSL information functions */
336 extern int	PQsslInUse(PGconn *conn);
337 extern void *PQsslStruct(PGconn *conn, const char *struct_name);
338 extern const char *PQsslAttribute(PGconn *conn, const char *attribute_name);
339 extern const char *const *PQsslAttributeNames(PGconn *conn);
340 
341 /* Get the OpenSSL structure associated with a connection. Returns NULL for
342  * unencrypted connections or if any other TLS library is in use. */
343 extern void *PQgetssl(PGconn *conn);
344 
345 /* Tell libpq whether it needs to initialize OpenSSL */
346 extern void PQinitSSL(int do_init);
347 
348 /* More detailed way to tell libpq whether it needs to initialize OpenSSL */
349 extern void PQinitOpenSSL(int do_ssl, int do_crypto);
350 
351 /* Return true if GSSAPI encryption is in use */
352 extern int	PQgssEncInUse(PGconn *conn);
353 
354 /* Returns GSSAPI context if GSSAPI is in use */
355 extern void *PQgetgssctx(PGconn *conn);
356 
357 /* Set verbosity for PQerrorMessage and PQresultErrorMessage */
358 extern PGVerbosity PQsetErrorVerbosity(PGconn *conn, PGVerbosity verbosity);
359 
360 /* Set CONTEXT visibility for PQerrorMessage and PQresultErrorMessage */
361 extern PGContextVisibility PQsetErrorContextVisibility(PGconn *conn,
362 													   PGContextVisibility show_context);
363 
364 /* Enable/disable tracing */
365 extern void PQtrace(PGconn *conn, FILE *debug_port);
366 extern void PQuntrace(PGconn *conn);
367 
368 /* Override default notice handling routines */
369 extern PQnoticeReceiver PQsetNoticeReceiver(PGconn *conn,
370 											PQnoticeReceiver proc,
371 											void *arg);
372 extern PQnoticeProcessor PQsetNoticeProcessor(PGconn *conn,
373 											  PQnoticeProcessor proc,
374 											  void *arg);
375 
376 /*
377  *	   Used to set callback that prevents concurrent access to
378  *	   non-thread safe functions that libpq needs.
379  *	   The default implementation uses a libpq internal mutex.
380  *	   Only required for multithreaded apps that use kerberos
381  *	   both within their app and for postgresql connections.
382  */
383 typedef void (*pgthreadlock_t) (int acquire);
384 
385 extern pgthreadlock_t PQregisterThreadLock(pgthreadlock_t newhandler);
386 
387 /* === in fe-exec.c === */
388 
389 /* Simple synchronous query */
390 extern PGresult *PQexec(PGconn *conn, const char *query);
391 extern PGresult *PQexecParams(PGconn *conn,
392 							  const char *command,
393 							  int nParams,
394 							  const Oid *paramTypes,
395 							  const char *const *paramValues,
396 							  const int *paramLengths,
397 							  const int *paramFormats,
398 							  int resultFormat);
399 extern PGresult *PQprepare(PGconn *conn, const char *stmtName,
400 						   const char *query, int nParams,
401 						   const Oid *paramTypes);
402 extern PGresult *PQexecPrepared(PGconn *conn,
403 								const char *stmtName,
404 								int nParams,
405 								const char *const *paramValues,
406 								const int *paramLengths,
407 								const int *paramFormats,
408 								int resultFormat);
409 
410 /* Interface for multiple-result or asynchronous queries */
411 extern int	PQsendQuery(PGconn *conn, const char *query);
412 extern int	PQsendQueryParams(PGconn *conn,
413 							  const char *command,
414 							  int nParams,
415 							  const Oid *paramTypes,
416 							  const char *const *paramValues,
417 							  const int *paramLengths,
418 							  const int *paramFormats,
419 							  int resultFormat);
420 extern int	PQsendPrepare(PGconn *conn, const char *stmtName,
421 						  const char *query, int nParams,
422 						  const Oid *paramTypes);
423 extern int	PQsendQueryPrepared(PGconn *conn,
424 								const char *stmtName,
425 								int nParams,
426 								const char *const *paramValues,
427 								const int *paramLengths,
428 								const int *paramFormats,
429 								int resultFormat);
430 extern int	PQsetSingleRowMode(PGconn *conn);
431 extern PGresult *PQgetResult(PGconn *conn);
432 
433 /* Routines for managing an asynchronous query */
434 extern int	PQisBusy(PGconn *conn);
435 extern int	PQconsumeInput(PGconn *conn);
436 
437 /* LISTEN/NOTIFY support */
438 extern PGnotify *PQnotifies(PGconn *conn);
439 
440 /* Routines for copy in/out */
441 extern int	PQputCopyData(PGconn *conn, const char *buffer, int nbytes);
442 extern int	PQputCopyEnd(PGconn *conn, const char *errormsg);
443 extern int	PQgetCopyData(PGconn *conn, char **buffer, int async);
444 
445 /* Deprecated routines for copy in/out */
446 extern int	PQgetline(PGconn *conn, char *string, int length);
447 extern int	PQputline(PGconn *conn, const char *string);
448 extern int	PQgetlineAsync(PGconn *conn, char *buffer, int bufsize);
449 extern int	PQputnbytes(PGconn *conn, const char *buffer, int nbytes);
450 extern int	PQendcopy(PGconn *conn);
451 
452 /* Set blocking/nonblocking connection to the backend */
453 extern int	PQsetnonblocking(PGconn *conn, int arg);
454 extern int	PQisnonblocking(const PGconn *conn);
455 extern int	PQisthreadsafe(void);
456 extern PGPing PQping(const char *conninfo);
457 extern PGPing PQpingParams(const char *const *keywords,
458 						   const char *const *values, int expand_dbname);
459 
460 /* Force the write buffer to be written (or at least try) */
461 extern int	PQflush(PGconn *conn);
462 
463 /*
464  * "Fast path" interface --- not really recommended for application
465  * use
466  */
467 extern PGresult *PQfn(PGconn *conn,
468 					  int fnid,
469 					  int *result_buf,
470 					  int *result_len,
471 					  int result_is_int,
472 					  const PQArgBlock *args,
473 					  int nargs);
474 
475 /* Accessor functions for PGresult objects */
476 extern ExecStatusType PQresultStatus(const PGresult *res);
477 extern char *PQresStatus(ExecStatusType status);
478 extern char *PQresultErrorMessage(const PGresult *res);
479 extern char *PQresultVerboseErrorMessage(const PGresult *res,
480 										 PGVerbosity verbosity,
481 										 PGContextVisibility show_context);
482 extern char *PQresultErrorField(const PGresult *res, int fieldcode);
483 extern int	PQntuples(const PGresult *res);
484 extern int	PQnfields(const PGresult *res);
485 extern int	PQbinaryTuples(const PGresult *res);
486 extern char *PQfname(const PGresult *res, int field_num);
487 extern int	PQfnumber(const PGresult *res, const char *field_name);
488 extern Oid	PQftable(const PGresult *res, int field_num);
489 extern int	PQftablecol(const PGresult *res, int field_num);
490 extern int	PQfformat(const PGresult *res, int field_num);
491 extern Oid	PQftype(const PGresult *res, int field_num);
492 extern int	PQfsize(const PGresult *res, int field_num);
493 extern int	PQfmod(const PGresult *res, int field_num);
494 extern char *PQcmdStatus(PGresult *res);
495 extern char *PQoidStatus(const PGresult *res);	/* old and ugly */
496 extern Oid	PQoidValue(const PGresult *res);	/* new and improved */
497 extern char *PQcmdTuples(PGresult *res);
498 extern char *PQgetvalue(const PGresult *res, int tup_num, int field_num);
499 extern int	PQgetlength(const PGresult *res, int tup_num, int field_num);
500 extern int	PQgetisnull(const PGresult *res, int tup_num, int field_num);
501 extern int	PQnparams(const PGresult *res);
502 extern Oid	PQparamtype(const PGresult *res, int param_num);
503 
504 /* Describe prepared statements and portals */
505 extern PGresult *PQdescribePrepared(PGconn *conn, const char *stmt);
506 extern PGresult *PQdescribePortal(PGconn *conn, const char *portal);
507 extern int	PQsendDescribePrepared(PGconn *conn, const char *stmt);
508 extern int	PQsendDescribePortal(PGconn *conn, const char *portal);
509 
510 /* Delete a PGresult */
511 extern void PQclear(PGresult *res);
512 
513 /* For freeing other alloc'd results, such as PGnotify structs */
514 extern void PQfreemem(void *ptr);
515 
516 /* Exists for backward compatibility.  bjm 2003-03-24 */
517 #define PQfreeNotify(ptr) PQfreemem(ptr)
518 
519 /* Error when no password was given. */
520 /* Note: depending on this is deprecated; use PQconnectionNeedsPassword(). */
521 #define PQnoPasswordSupplied	"fe_sendauth: no password supplied\n"
522 
523 /* Create and manipulate PGresults */
524 extern PGresult *PQmakeEmptyPGresult(PGconn *conn, ExecStatusType status);
525 extern PGresult *PQcopyResult(const PGresult *src, int flags);
526 extern int	PQsetResultAttrs(PGresult *res, int numAttributes, PGresAttDesc *attDescs);
527 extern void *PQresultAlloc(PGresult *res, size_t nBytes);
528 extern size_t PQresultMemorySize(const PGresult *res);
529 extern int	PQsetvalue(PGresult *res, int tup_num, int field_num, char *value, int len);
530 
531 /* Quoting strings before inclusion in queries. */
532 extern size_t PQescapeStringConn(PGconn *conn,
533 								 char *to, const char *from, size_t length,
534 								 int *error);
535 extern char *PQescapeLiteral(PGconn *conn, const char *str, size_t len);
536 extern char *PQescapeIdentifier(PGconn *conn, const char *str, size_t len);
537 extern unsigned char *PQescapeByteaConn(PGconn *conn,
538 										const unsigned char *from, size_t from_length,
539 										size_t *to_length);
540 extern unsigned char *PQunescapeBytea(const unsigned char *strtext,
541 									  size_t *retbuflen);
542 
543 /* These forms are deprecated! */
544 extern size_t PQescapeString(char *to, const char *from, size_t length);
545 extern unsigned char *PQescapeBytea(const unsigned char *from, size_t from_length,
546 									size_t *to_length);
547 
548 
549 
550 /* === in fe-print.c === */
551 
552 extern void PQprint(FILE *fout, /* output stream */
553 					const PGresult *res,
554 					const PQprintOpt *ps);	/* option structure */
555 
556 /*
557  * really old printing routines
558  */
559 extern void PQdisplayTuples(const PGresult *res,
560 							FILE *fp,	/* where to send the output */
561 							int fillAlign,	/* pad the fields with spaces */
562 							const char *fieldSep,	/* field separator */
563 							int printHeader,	/* display headers? */
564 							int quiet);
565 
566 extern void PQprintTuples(const PGresult *res,
567 						  FILE *fout,	/* output stream */
568 						  int printAttName, /* print attribute names */
569 						  int terseOutput,	/* delimiter bars */
570 						  int width);	/* width of column, if 0, use variable
571 										 * width */
572 
573 
574 /* === in fe-lobj.c === */
575 
576 /* Large-object access routines */
577 extern int	lo_open(PGconn *conn, Oid lobjId, int mode);
578 extern int	lo_close(PGconn *conn, int fd);
579 extern int	lo_read(PGconn *conn, int fd, char *buf, size_t len);
580 extern int	lo_write(PGconn *conn, int fd, const char *buf, size_t len);
581 extern int	lo_lseek(PGconn *conn, int fd, int offset, int whence);
582 extern pg_int64 lo_lseek64(PGconn *conn, int fd, pg_int64 offset, int whence);
583 extern Oid	lo_creat(PGconn *conn, int mode);
584 extern Oid	lo_create(PGconn *conn, Oid lobjId);
585 extern int	lo_tell(PGconn *conn, int fd);
586 extern pg_int64 lo_tell64(PGconn *conn, int fd);
587 extern int	lo_truncate(PGconn *conn, int fd, size_t len);
588 extern int	lo_truncate64(PGconn *conn, int fd, pg_int64 len);
589 extern int	lo_unlink(PGconn *conn, Oid lobjId);
590 extern Oid	lo_import(PGconn *conn, const char *filename);
591 extern Oid	lo_import_with_oid(PGconn *conn, const char *filename, Oid lobjId);
592 extern int	lo_export(PGconn *conn, Oid lobjId, const char *filename);
593 
594 /* === in fe-misc.c === */
595 
596 /* Get the version of the libpq library in use */
597 extern int	PQlibVersion(void);
598 
599 /* Determine length of multibyte encoded char at *s */
600 extern int	PQmblen(const char *s, int encoding);
601 
602 /* Determine display length of multibyte encoded char at *s */
603 extern int	PQdsplen(const char *s, int encoding);
604 
605 /* Get encoding id from environment variable PGCLIENTENCODING */
606 extern int	PQenv2encoding(void);
607 
608 /* === in fe-auth.c === */
609 
610 extern char *PQencryptPassword(const char *passwd, const char *user);
611 extern char *PQencryptPasswordConn(PGconn *conn, const char *passwd, const char *user, const char *algorithm);
612 
613 /* === in encnames.c === */
614 
615 extern int	pg_char_to_encoding(const char *name);
616 extern const char *pg_encoding_to_char(int encoding);
617 extern int	pg_valid_server_encoding_id(int encoding);
618 
619 #ifdef __cplusplus
620 }
621 #endif
622 
623 #endif							/* LIBPQ_FE_H */
624