The Annoyance Filter.pdf - Fourmilab

56 QUOTED-PRINTABLE MIME DECODER ANNOYANCE-FILTER §58
58. Quoted-Printable MIME decoder.
The quotedPrintableMIMEdecoder decodes an input stream encoded as MIME “Quoted-Printable”
per RFC 1521. This is based on my stand-alone Quoted-Printable decoder.
〈 Class definitions 10 〉 +≡
class quotedPrintableMIMEdecoder : public MIMEdecoder {
public:
quotedPrintableMIMEdecoder( )
{
atEndOfLine = false ;
}
string name (void) const
{
return "Quoted−Printable";
}
int getDecodedChar (void);
static string decodeEscapedText (const string s, mailFolder ∗m = Λ);
protected:
bool atEndOfLine ;
int getNextChar (void);
static int hex to nybble (const int ch );
};
59. Get the next decoded character from the stream, expanding “=” escape sequences.
〈 Class implementations 11 〉 +≡
int quotedPrintableMIMEdecoder ::getDecodedChar (void)
{
int ch ;
}
〈 Check for look ahead character 55 〉;
while (true ) {
ch = getNextChar ( );
if (ch ≡ ’=’) {
〈 Decode equal sign escape 60 〉;
}
else {
return ch ;
}
}