Encapsulating the DOS IOCTL Interface

Listing 5 chandle.h — adds character-device specific capability to class Ioctl Handle

#ifndef _CHANDLE_H
#define _CHANDLE_H
#include "iohandle.h"

//ANSI display information ......
struct ANSIdata    {
   char info;       //info level (=0)
   char zero_1;        //reserved (=0)
   int block_length;   //param block length
                    //(start at next field)
   int flags;      //0x0001 = intense
                //0x0002 = blink
                //other bits reserved (=0)
   char mode;      //1 = text, 2 = graphics
   char zero_2;    //reserved (=0)
   int numcolors;  //# colors (= 2**n, where
                // n == 0, 1, 2, 4, 8;
                // 0 == monochrome )
   int pix_cols;   //pixel columns
   int pix_rows;   //pixel rows
   int txt_cols;   //text columns
   int txt_rows;   //text rows
   };

class charHandle: public IoctlHandle {
protected:
   int _cat;       //current device category
   charHandle( const char *device );  //constructor
   void handle_info( int, unsigned ); //set dev info
   unsigned ioctl_data( ioctl_cmd fn, unsigned count,
                                void *buffer );
   int char_ioctl( char_cmd minor_code,
                void *param_block );
public:
   static charHandle *Init(const char *device );
   ~charHandle() { }   //~IoctlHandle() closes_handle
   int deviceCat(void) { return _cat; }
   unsigned setDeviceInfo( unsigned newinfo )
      {   handle_info( _handle, newinfo );
         return handleInfo();         }
   int isCooked(void)       //!0 if ASCII mode
      { return !(binary & info);   }
   int isRaw( void )        //!0 if Binary mode
      { return (binary & _info);  }
   int hasIoctlChar(void) { return ioctl & _info; }
   int deviceReadyIn(void ) //!0=ready, 0 not ready
      {   return inputStatus(); }
   int deviceReadyOut(void) //!0=ready, 0 not ready
      {   return outputStatus(); }
   int sendIoctl( unsigned *count, void *data);
   int readIoctl( unsigned *count, void *data);
   unsigned busyCount( void );  //get count
   unsigned busyCount( unsigned count );  //set count
   int getANSIdata( struct ANSIdata *dis);
   int setANSIdata( struct ANSIdata *dis);
};  //.... end class charHandle
#endif // __CHANDLE_H

// End of File