Source: nkf.h

#ifndef NKF_H
#define NKF_H

class Nkf {
  public:
    Nkf();
    virtual ~Nkf();

    enum NkfCode{JIS, SJIS, EUC};

    void reset();
    void setConversion(bool flag);
    void setInputCode(NkfCode code);
    void setBrokenInput(int mode = -1);
    void setDecodeMime(bool flag);
    void setDecodeBase64(bool flag);
    void setDecodeQuotedStream(bool flag);
    void setOutputBuffered(bool flag);
    void setOutputCode(NkfCode code);
    void setLatin1Support(bool falg);
    void setOutputSequenceToDesignateAscii(char c);
    void setOutputSequenceToDesignateJisKanji(char c);
    void setAssumeHankakuKana(bool flag);
    void setConvertZenkakuAlphabetToAscii(int mode = -1);
    void setFolding(int f);
    void setAddCR(bool flag);
    void setDeleteCR(bool flag);
    void setXcryptRot1347(bool flag);
    bool check();

    NkfCode InputCode(void);
    NkfCode OutputCode(void);

    int begin();
    int end();

  protected:
    int convert();
    int noconvert();

    int h_conv(register int c2, register int c1);
    int push_hold_buf(int c2, int c1);
    void s_iconv(register int c2,register int c1);
    void e_oconv(register int c2,register int c1);
    void s_oconv(register int c2,register int c1);
    void j_oconv(register int c2,register int c1);
    int fold(register int c2,register int c1);
    int pre_convert(register int c1,register int c2);

    int mime_begin();
    int mime_get_char();
    int mime_unget_char(unsigned int c);
    int mime_integrity(unsigned char *p);

    virtual int get_char() = 0;
    virtual int unget_char(int c) = 0;
    virtual int put_char(int c) = 0;

    unsigned char * hold_buf;
    int             hold_count;

    /* MIME preprocessor fifo */
    unsigned char * mime_buf;
    unsigned int    mime_top;
    unsigned int    mime_last;   /* decoded */
    unsigned int    mime_input;  /* undecoded */

    /* flags */
    int unbuf_f:1;
    int estab_f:1;
    int nop_f:1;
    int rot_f:1;          /* rot14/43 mode */
    int input_f;          /* non fixed input code  */
    int alpha_f;          /* convert JIx0208 alphbet to ASCII */
    int mime_f:1;         /* convert MIME B base64 or Q */
    int mimebuf_f;        /* MIME buffered input */
    int broken_f;         /* convert ESC-less broken JIS */
    int iso8859_f:1;      /* ISO8859 through */
    int iso8859_f_save:1;
    int x0201_f;          /* Assume JISX0201 kana */

    NkfCode input_code;

    /* X0208 -> ASCII converter */
    int c1_return;

    /* fold parameter */
    int line;  /* chars in line */
    int prev;
    int fold_f:1;
    int fold_len;

    /* options */
    char kanji_intro, ascii_intro;

    /* converters */
    void (Nkf::*iconv) (int c2, int c1); /* s_iconv or oconv */
    void (Nkf::*oconv) (int c2, int c1); /* [ejs]_oconv */

    /* Global states */
    int output_mode,  /* output kanji mode */
        input_mode,   /* input kanji mode */
        shift_mode;   /* TRUE shift out, or X0201  */
    int mime_mode;    /* MIME mode B base64, Q hex */

    int add_cr:1;
    int del_cr:1;

  private:
};

class StringNkf : public Nkf {
  public:
    char *convert(const char *string, int length = 0);

  protected:
    int get_char();
    int unget_char(int c);
    int put_char(int c);

  private:
    const char *istring;
    int ilength;
    int ioffset;

    char *ostring;
    int olength;
    int ooffset;
};

class FileNkf : public Nkf {
  public:
    int convert(FILE *in, FILE *out);

  protected:
    int get_char();
    int unget_char(int c);
    int put_char(int c);

  private:
    FILE *ifile;
    FILE *ofile;
};

#endif /* NKF_H */