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// Myiodemo.cpp
// This is a trivial program which uses the myio loopback class
// to demonstrate the basics on writing an io interface using
// the AT&T C++ iostream classes.
// The program simply provides the ability to selectively add
// to or read from a Myio instance and display information to
// assist in understanding how it all works.
//
# include "Mystream.h" // This includes Myio.h and iostream.h
# include "myLine.h"
# include <conio.h> // For getch()
# include <ctype.h> // For toupper()
# include <string.h>
# define NL char('\n')
// Let's do the "application is a class" trick
class myApplication
{
// Defines a pointer to member function type
// used for dispatching the menu
typedef void (myApplication::*pvf) (void);
public:
myApplication (void) : mio() {}
int execute (void);
private:
iostream & stream (void) { return mio.stream(); }
int domenu (void);
void send (void);
void read (void);
void disp (void);
void peek (void);
void flsh (void);
void stat (void);
pvf choice; // Function called to execute
Myio mio; // IO object
};
void
myApplication::disp (void)
{
cout << "Mystream status:" << NL
<< "Chrs in output buffer = " << stream().rdbuf()->out_waiting() << NL
<< "Chrs in input buffer = " << stream().rdbuf()->in_avail() << NL
<< "Myio object status = "
<< mio.count() << char('/') << mio.size()
<< " LastWrite=" << (mio.writeok() ? "OK" : "Incomplete")
<< " LastRead=" << (mio.readok() ? "OK" : "EOF")
<< endl;
}
// Request a line and send it to the IO device
void
myApplication::send (void)
{
cout << NL << "Enter text to write - press <ENTER> when done\n:";
myLine L;
cin >> L;
int l = strlen(L);
if (!l)
cerr << "Nothing entered." << endl;
else
{
cout << "Writing '"
<< L
<< char('\'')
<< endl;
stream() << L << NL; // Send the entered data, NL terminated
cout << "Chrs written to Myio object = " << (l + 1) << NL;
disp ();
}
}
void
myApplication::read (void)
{
cout << NL << "Reading a line from object:" << NL;
myLine L;
mio.stream().clear();
mio.stream() >> L;
int l = strlen(L);
if (!l)
{
cout << "Nothing read." << endl;
mio.stream().clear(); // Clear EOF status
}
else
{
cout << "Read '"
<< L
<< char('\'')
<< endl;
cout << "Chrs read from Myio object = " << (l + 1) << NL;
disp ();
}
}
void
myApplication::flsh (void)
{
cout << NL << "Flushing stream" << endl;
stream() << flush;
disp ();
}
void
myApplication::stat (void)
{
cout << NL << "Myio object buffer dump:" << NL;
mio.dump();
disp ();
stream().rdbuf()->dbp(); // Dump stream info
}
int
myApplication::domenu (void)
{
cout << NL
<< "W)rite R)ead D)ump F)lush Q)uit\n"
<< "Select: "
<< flush; // Need to flush here for portability
int key;
for (;;)
{
key = getch ();
switch (toupper(key))
{
case 'W': choice = &myApplication::send; break;
case 'R': choice = &myApplication::read; break;
case 'D': choice = &myApplication::stat; break;
case 'F': choice = &myApplication::flsh; break;
case 'Q': key = 0; break;
default:
continue;
}
cout << char(key) << endl;
break;
}
return key;
}
int // This is really the application
myApplication::execute (void)
{
while (domenu ())
(this->*choice) ();
return 0;
}
int
main (void)
{
myApplication Demo; // Declare the application
return Demo.execute (); // go for it!
}
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