dbfopen.c

一个关于shapefile的类库,包括dll,lib文件和头文件,大家也可到开源GIS上面下载

	strncpy((char *) (pabyRec+psDBF->panFieldOffset[iField]),
		(char *) pValue, j );
	break;
    }

    return( nRetResult );
}

/************************************************************************/
/*                     DBFWriteAttributeDirectly()                      */
/*                                                                      */
/*      Write an attribute record to the file, but without any          */
/*      reformatting based on type.  The provided buffer is written     */
/*      as is to the field position in the record.                      */
/************************************************************************/

int DBFWriteAttributeDirectly(DBFHandle psDBF, int hEntity, int iField,
                              void * pValue )

{
    int	       	nRecordOffset, i, j;
    unsigned char	*pabyRec;

/* -------------------------------------------------------------------- */
/*	Is this a valid record?						*/
/* -------------------------------------------------------------------- */
    if( hEntity < 0 || hEntity > psDBF->nRecords )
        return( FALSE );

    if( psDBF->bNoHeader )
        DBFWriteHeader(psDBF);

/* -------------------------------------------------------------------- */
/*      Is this a brand new record?                                     */
/* -------------------------------------------------------------------- */
    if( hEntity == psDBF->nRecords )
    {
	DBFFlushRecord( psDBF );

	psDBF->nRecords++;
	for( i = 0; i < psDBF->nRecordLength; i++ )
	    psDBF->pszCurrentRecord[i] = ' ';

	psDBF->nCurrentRecord = hEntity;
    }

/* -------------------------------------------------------------------- */
/*      Is this an existing record, but different than the last one     */
/*      we accessed?                                                    */
/* -------------------------------------------------------------------- */
    if( psDBF->nCurrentRecord != hEntity )
    {
	DBFFlushRecord( psDBF );

	nRecordOffset = psDBF->nRecordLength * hEntity + psDBF->nHeaderLength;

	fseek( psDBF->fp, nRecordOffset, 0 );
	fread( psDBF->pszCurrentRecord, psDBF->nRecordLength, 1, psDBF->fp );

	psDBF->nCurrentRecord = hEntity;
    }

    pabyRec = (unsigned char *) psDBF->pszCurrentRecord;

/* -------------------------------------------------------------------- */
/*      Assign all the record fields.                                   */
/* -------------------------------------------------------------------- */
    if( (int)strlen((char *) pValue) > psDBF->panFieldSize[iField] )
        j = psDBF->panFieldSize[iField];
    else
    {
        memset( pabyRec+psDBF->panFieldOffset[iField], ' ',
                psDBF->panFieldSize[iField] );
        j = strlen((char *) pValue);
    }

    strncpy((char *) (pabyRec+psDBF->panFieldOffset[iField]),
            (char *) pValue, j );

    psDBF->bCurrentRecordModified = TRUE;
    psDBF->bUpdated = TRUE;

    return( TRUE );
}

/************************************************************************/
/*                      DBFWriteDoubleAttribute()                       */
/*                                                                      */
/*      Write a double attribute.                                       */
/************************************************************************/

int SHPAPI_CALL
DBFWriteDoubleAttribute( DBFHandle psDBF, int iRecord, int iField,
                         double dValue )

{
    return( DBFWriteAttribute( psDBF, iRecord, iField, (void *) &dValue ) );
}

/************************************************************************/
/*                      DBFWriteIntegerAttribute()                      */
/*                                                                      */
/*      Write a integer attribute.                                      */
/************************************************************************/

int SHPAPI_CALL
DBFWriteIntegerAttribute( DBFHandle psDBF, int iRecord, int iField,
                          int nValue )

{
    double	dValue = nValue;

    return( DBFWriteAttribute( psDBF, iRecord, iField, (void *) &dValue ) );
}

/************************************************************************/
/*                      DBFWriteStringAttribute()                       */
/*                                                                      */
/*      Write a string attribute.                                       */
/************************************************************************/

int SHPAPI_CALL
DBFWriteStringAttribute( DBFHandle psDBF, int iRecord, int iField,
                         const char * pszValue )

{
    return( DBFWriteAttribute( psDBF, iRecord, iField, (void *) pszValue ) );
}

/************************************************************************/
/*                      DBFWriteNULLAttribute()                         */
/*                                                                      */
/*      Write a string attribute.                                       */
/************************************************************************/

int SHPAPI_CALL
DBFWriteNULLAttribute( DBFHandle psDBF, int iRecord, int iField )

{
    return( DBFWriteAttribute( psDBF, iRecord, iField, NULL ) );
}

/************************************************************************/
/*                      DBFWriteLogicalAttribute()                      */
/*                                                                      */
/*      Write a logical attribute.                                      */
/************************************************************************/

int SHPAPI_CALL
DBFWriteLogicalAttribute( DBFHandle psDBF, int iRecord, int iField,
		       const char lValue)

{
    return( DBFWriteAttribute( psDBF, iRecord, iField, (void *) (&lValue) ) );
}

/************************************************************************/
/*                         DBFWriteTuple()                              */
/*									*/
/*	Write an attribute record to the file.				*/
/************************************************************************/

int SHPAPI_CALL
DBFWriteTuple(DBFHandle psDBF, int hEntity, void * pRawTuple )

{
    int	       	nRecordOffset, i;
    unsigned char	*pabyRec;

/* -------------------------------------------------------------------- */
/*	Is this a valid record?						*/
/* -------------------------------------------------------------------- */
    if( hEntity < 0 || hEntity > psDBF->nRecords )
        return( FALSE );

    if( psDBF->bNoHeader )
        DBFWriteHeader(psDBF);

/* -------------------------------------------------------------------- */
/*      Is this a brand new record?                                     */
/* -------------------------------------------------------------------- */
    if( hEntity == psDBF->nRecords )
    {
	DBFFlushRecord( psDBF );

	psDBF->nRecords++;
	for( i = 0; i < psDBF->nRecordLength; i++ )
	    psDBF->pszCurrentRecord[i] = ' ';

	psDBF->nCurrentRecord = hEntity;
    }

/* -------------------------------------------------------------------- */
/*      Is this an existing record, but different than the last one     */
/*      we accessed?                                                    */
/* -------------------------------------------------------------------- */
    if( psDBF->nCurrentRecord != hEntity )
    {
	DBFFlushRecord( psDBF );

	nRecordOffset = psDBF->nRecordLength * hEntity + psDBF->nHeaderLength;

	fseek( psDBF->fp, nRecordOffset, 0 );
	fread( psDBF->pszCurrentRecord, psDBF->nRecordLength, 1, psDBF->fp );

	psDBF->nCurrentRecord = hEntity;
    }

    pabyRec = (unsigned char *) psDBF->pszCurrentRecord;

    memcpy ( pabyRec, pRawTuple,  psDBF->nRecordLength );

    psDBF->bCurrentRecordModified = TRUE;
    psDBF->bUpdated = TRUE;

    return( TRUE );
}

/************************************************************************/
/*                          DBFReadTuple()                              */
/*                                                                      */
/*      Read one of the attribute fields of a record.                   */
/************************************************************************/

const char SHPAPI_CALL1(*)
DBFReadTuple(DBFHandle psDBF, int hEntity )

{
    int	       	nRecordOffset;
    unsigned char	*pabyRec;
    static char	*pReturnTuple = NULL;

    static int	nTupleLen = 0;

/* -------------------------------------------------------------------- */
/*	Have we read the record?					*/
/* -------------------------------------------------------------------- */
    if( hEntity < 0 || hEntity >= psDBF->nRecords )
        return( NULL );

    if( psDBF->nCurrentRecord != hEntity )
    {
	DBFFlushRecord( psDBF );

	nRecordOffset = psDBF->nRecordLength * hEntity + psDBF->nHeaderLength;

	fseek( psDBF->fp, nRecordOffset, 0 );
	fread( psDBF->pszCurrentRecord, psDBF->nRecordLength, 1, psDBF->fp );

	psDBF->nCurrentRecord = hEntity;
    }

    pabyRec = (unsigned char *) psDBF->pszCurrentRecord;

    if ( nTupleLen < psDBF->nRecordLength) {
      nTupleLen = psDBF->nRecordLength;
      pReturnTuple = (char *) SfRealloc(pReturnTuple, psDBF->nRecordLength);
    }
    
    memcpy ( pReturnTuple, pabyRec, psDBF->nRecordLength );
        
    return( pReturnTuple );
}

/************************************************************************/
/*                          DBFCloneEmpty()                              */
/*                                                                      */
/*      Read one of the attribute fields of a record.                   */
/************************************************************************/

DBFHandle SHPAPI_CALL
DBFCloneEmpty(DBFHandle psDBF, const char * pszFilename ) 
{
    DBFHandle	newDBF;

   newDBF = DBFCreate ( pszFilename );
   if ( newDBF == NULL ) return ( NULL ); 
   
   newDBF->pszHeader = (char *) malloc ( 32 * psDBF->nFields );
   memcpy ( newDBF->pszHeader, psDBF->pszHeader, 32 * psDBF->nFields );
   
   newDBF->nFields = psDBF->nFields;
   newDBF->nRecordLength = psDBF->nRecordLength;
   newDBF->nHeaderLength = 32 * (psDBF->nFields+1);
    
   newDBF->panFieldOffset = (int *) malloc ( sizeof(int) * psDBF->nFields ); 
   memcpy ( newDBF->panFieldOffset, psDBF->panFieldOffset, sizeof(int) * psDBF->nFields );
   newDBF->panFieldSize = (int *) malloc ( sizeof(int) * psDBF->nFields );
   memcpy ( newDBF->panFieldSize, psDBF->panFieldSize, sizeof(int) * psDBF->nFields );
   newDBF->panFieldDecimals = (int *) malloc ( sizeof(int) * psDBF->nFields );
   memcpy ( newDBF->panFieldDecimals, psDBF->panFieldDecimals, sizeof(int) * psDBF->nFields );
   newDBF->pachFieldType = (char *) malloc ( sizeof(int) * psDBF->nFields );
   memcpy ( newDBF->pachFieldType, psDBF->pachFieldType, sizeof(int) * psDBF->nFields );

   newDBF->bNoHeader = TRUE;
   newDBF->bUpdated = TRUE;
   
   DBFWriteHeader ( newDBF );
   DBFClose ( newDBF );
   
   newDBF = DBFOpen ( pszFilename, "rb+" );

   return ( newDBF );
}

/************************************************************************/
/*                       DBFGetNativeFieldType()                        */
/*                                                                      */
/*      Return the DBase field type for the specified field.            */
/*                                                                      */
/*      Value can be one of: 'C' (String), 'D' (Date), 'F' (Float),     */
/*                           'N' (Numeric, with or without decimal),    */
/*                           'L' (Logical),                             */
/*                           'M' (Memo: 10 digits .DBT block ptr)       */
/************************************************************************/

char SHPAPI_CALL
DBFGetNativeFieldType( DBFHandle psDBF, int iField )

{
    if( iField >=0 && iField < psDBF->nFields )
        return psDBF->pachFieldType[iField];

    return  ' ';
}

/************************************************************************/
/*                            str_to_upper()                            */
/************************************************************************/

static void str_to_upper (char *string)
{
    int len;
    short i = -1;

    len = strlen (string);

    while (++i < len)
        if (isalpha(string[i]) && islower(string[i]))
            string[i] = toupper ((int)string[i]);
}

/************************************************************************/
/*                          DBFGetFieldIndex()                          */
/*                                                                      */
/*      Get the index number for a field in a .dbf file.                */
/*                                                                      */
/*      Contributed by Jim Matthews.                                    */
/************************************************************************/

int SHPAPI_CALL
DBFGetFieldIndex(DBFHandle psDBF, const char *pszFieldName)

{
    char          name[12], name1[12], name2[12];
    int           i;

    strncpy(name1, pszFieldName,11);
    name1[11] = '\0';
    str_to_upper(name1);

    for( i = 0; i < DBFGetFieldCount(psDBF); i++ )
    {
        DBFGetFieldInfo( psDBF, i, name, NULL, NULL );
        strncpy(name2,name,11);
        str_to_upper(name2);

        if(!strncmp(name1,name2,10))
            return(i);
    }
    return(-1);
}