Creating Base64 DEcoded files using streams from ENcoded files with Freepascal [duplicate] - base64

Question

Can you tell me how can I do that? Is there any Freepascal unit that can do this for me? I need that so my program can store binary data in it's XML-based fileformat.

Answer 1

Use the base64 unit and its two classes, TBase64EncodingStream and TBase64DecodingStream.
Here is a simple example:
program demo;
uses Classes, base64;
var
DecodedStream: TStringStream;
EncodedStream: TStringStream;
Encoder: TBase64EncodingStream;
Output: string;
begin
DecodedStream := TStringStream.Create('Hello World!');
EncodedStream := TStringStream.Create('');
Encoder := TBase64EncodingStream.Create(EncodedStream);
Encoder.CopyFrom(DecodedStream, DecodedStream.Size);
Output := EncodedStream.DataString;
{ Outputs 'SGVsbG8gV29ybGQh' }
WriteLn(Output);
DecodedStream.Free;
EncodedStream.Free;
Encoder.Free;
end.
And, in the opposite direction:
program demo;
uses Classes, base64;
var
DecodedStream: TStringStream;
EncodedStream: TStringStream;
Decoder: TBase64DecodingStream;
Output: string;
begin
EncodedStream := TStringStream.Create('SGVsbG8gV29ybGQh');
DecodedStream := TStringStream.Create('');
Decoder := TBase64DecodingStream.Create(EncodedStream);
DecodedStream.CopyFrom(Decoder, Decoder.Size);
Output := DecodedStream.DataString;
{ Outputs 'Hello World!' }
WriteLn(Output);
DecodedStream.Free;
EncodedStream.Free;
Decoder.Free;
end.
or the shorthands encodestringbase64 and decodestringbase64 (2.4.4+) for non stream based usage:
Uses Base64;
var
s : AnsiString;
Begin
s:=EncodeStringBase64('Hello world!');
Writeln('Encoded : ',s);
s:=DecodeStringBase64(s);
Writeln('Decoded again : ',s);
end.