1.Dd December 19, 2018 2.Dt SQLITE3_FILE_CONTROL 3 3.Os 4.Sh NAME 5.Nm sqlite3_file_control 6.Nd Low-Level Control Of Database Files 7.Sh SYNOPSIS 8.Ft int 9.Fo sqlite3_file_control 10.Fa "sqlite3*" 11.Fa "const char *zDbName" 12.Fa "int op" 13.Fa "void*" 14.Fc 15.Sh DESCRIPTION 16The sqlite3_file_control() interface makes a 17direct call to the xFileControl method for the sqlite3_io_methods 18object associated with a particular database identified by the second 19argument. 20The name of the database is "main" for the main database or "temp" 21for the TEMP database, or the name that appears after the AS keyword 22for databases that are added using the ATTACH SQL command. 23A NULL pointer can be used in place of "main" to refer to the main 24database file. 25The third and fourth parameters to this routine are passed directly 26through to the second and third parameters of the xFileControl method. 27The return value of the xFileControl method becomes the return value 28of this routine. 29.Pp 30A few opcodes for sqlite3_file_control() are 31handled directly by the SQLite core and never invoke the sqlite3_io_methods.xFileControl 32method. 33The SQLITE_FCNTL_FILE_POINTER value for the 34op parameter causes a pointer to the underlying sqlite3_file 35object to be written into the space pointed to by the 4th parameter. 36The SQLITE_FCNTL_JOURNAL_POINTER works 37similarly except that it returns the sqlite3_file object 38associated with the journal file instead of the main database. 39The SQLITE_FCNTL_VFS_POINTER opcode returns 40a pointer to the underlying sqlite3_vfs object for the file. 41The SQLITE_FCNTL_DATA_VERSION returns the 42data version counter from the pager. 43.Pp 44If the second parameter (zDbName) does not match the name of any open 45database file, then SQLITE_ERROR is returned. 46This error code is not remembered and will not be recalled by sqlite3_errcode() 47or sqlite3_errmsg(). 48The underlying xFileControl method might also return SQLITE_ERROR. 49There is no way to distinguish between an incorrect zDbName and an 50SQLITE_ERROR return from the underlying xFileControl method. 51.Pp 52.Sh SEE ALSO 53.Xr SQLITE_FCNTL_LOCKSTATE 3 , 54.Xr sqlite3_errcode 3 , 55.Xr sqlite3_file 3 , 56.Xr sqlite3_file_control 3 , 57.Xr sqlite3_io_methods 3 , 58.Xr sqlite3_vfs 3 , 59.Xr SQLITE_FCNTL_LOCKSTATE 3 60