BASE64 (FUN)

FUNCTION BASE64 : PT_SIZE

encodes 8 bit binary data into ASCII data

A text block (string, binary, array of bytes) will be base64 encoded. The maximum of the block is set in the TextBlockSize parameter. This size can be changed but must be divisible by 3.

If the text block is only a part of a text and followed by more text, the size must be TextBlockSize.iBlockSize and the isLastBlock variable must be set to FALSE. If a text is not followed by another block, the specific length of it must be used and isLastBlock has to be set to FALSE, as shown in the following example. The reason is three 8-bit letters will become four 6-bit letters. If only two 8-Bit letters are remaining at the end, the encoded text is filled with "=". This must only be at the end of a text.

Example:

StringToConvert : PT_SIZE;
EncodedString  : PT_SIZE;
byError        : BYTE;
sText          : STRING := 'This is a test string.';

StringToConvert.uiSize := LEN(sText); (* When another block follows, use the size TextBlockSize.iBlockSize
                                     and set isLastBlock to FALSE. *)
StringToConvert.pString := ADR(sText);
EncodedString := Base64(TextToEncode := StringToConvert, isLastBlock := TRUE, pbyError := ADR(byError));

InOut: