DOS to Linux migration library

[Rob Wehrli]

Alan,

Have you seen the following?

Take Care.

Rob!


------------------------------------------------------------------------
--------

"_sleep()" can be replaced by a number of Linux (UNIX) functions,
depending on the time resolution. Below are some of these functions
(reference the man pages).

sleep() - second resolution
usleep() - microsecond resolution
nanosleep() - nanosecond resolution


getch() is getchar() or use the readch() function I provide below.

kbhit() is not available on Linux (UNIX), it is a DOS function. Below is
some code (functions) to replace the "kbhit" functionality (this code is
from a book called "Beginning Linux Programming", from Wrox Press --
www.wrox.com -- you can download the Code Examples from the Book at this
Site):

CCODE
/********************************************************************/

KBHIT.H

#ifndef KBHITh
#define KBHITh

void   init_keyboard(void);
void   close_keyboard(void);
int      kbhit(void);
int     readch(void);

#endif

KBHIT.C

#include "kbhit.h"
#include <termios.h>
#include <unistd.h>   // for read()

static struct termios initial_settings, new_settings;
static int peek_character = -1;

void init_keyboard()
{
    tcgetattr(0,&initial_settings);
    new_settings = initial_settings;
    new_settings.c_lflag &= ~ICANON;
    new_settings.c_lflag &= ~ECHO;
    new_settings.c_lflag &= ~ISIG;
    new_settings.c_cc[VMIN] = 1;
    new_settings.c_cc[VTIME] = 0;
    tcsetattr(0, TCSANOW, &new_settings);
}

void close_keyboard()
{
    tcsetattr(0, TCSANOW, &initial_settings);
}

int kbhit()
{
unsigned char ch;
int nread;

    if (peek_character != -1) return 1;
    new_settings.c_cc[VMIN]=0;
    tcsetattr(0, TCSANOW, &new_settings);
    nread = read(0,&ch,1);
    new_settings.c_cc[VMIN]=1;
    tcsetattr(0, TCSANOW, &new_settings);
    if(nread == 1)
    {
        peek_character = ch;
        return 1;
    }
    return 0;
}

int readch()
{
char ch;

    if(peek_character != -1)
    {
        ch = peek_character;
        peek_character = -1;
        return ch;
    }
    read(0,&ch,1);
    return ch;
}

/***************************************************/
C++ CODE
///////////////////////////////////////////////////////////
// KBHIT.H

#ifndef KBHITh
#define KBHITh

#include <termios.h>

class keyboard
{
public:

      keyboard();
    ~keyboard();
    int kbhit();
    int getch();

private:

    struct termios initial_settings, new_settings;
    int peek_character;

};

#endif

// KBHIT.CPP

#include "kbhit.h"
#include <unistd.h> // read()

keyboard::keyboard()
{
    tcgetattr(0,&initial_settings);
    new_settings = initial_settings;
    new_settings.c_lflag &= ~ICANON;
    new_settings.c_lflag &= ~ECHO;
    new_settings.c_lflag &= ~ISIG;
    new_settings.c_cc[VMIN] = 1;
    new_settings.c_cc[VTIME] = 0;
    tcsetattr(0, TCSANOW, &new_settings);
    peek_character=-1;
}

keyboard::~keyboard()
{
    tcsetattr(0, TCSANOW, &initial_settings);
}

int keyboard::kbhit()
{
unsigned char ch;
int nread;

    if (peek_character != -1) return 1;
    new_settings.c_cc[VMIN]=0;
    tcsetattr(0, TCSANOW, &new_settings);
    nread = read(0,&ch,1);
    new_settings.c_cc[VMIN]=1;
    tcsetattr(0, TCSANOW, &new_settings);

    if (nread == 1)
    {
        peek_character = ch;
        return 1;
    }
    return 0;
}

int keyboard::getch()
{
char ch;

    if (peek_character != -1)
    {
        ch = peek_character;
        peek_character = -1;
    } else read(0,&ch,1);

    return ch;
}

> -----Original Message-----
> From: plug-devel-admin@lists.PLUG.phoenix.az.us
> [mailto:plug-devel-admin@lists.PLUG.phoenix.az.us]On Behalf Of Alan
> Dayley
> Sent: Friday, March 21, 2003 11:16 PM
> To: plug-devel@lists.PLUG.phoenix.az.us
> Subject: DOS to Linux migration library
>
>
> I have begun an adventure to migrate some DOS applications,
> written in C, to
> be native Linux applications.  In an ideal world, I could
> just drop the code
> in gcc and have it come out executable on the other end.  Of
> course this is
> not going to happen.
>
> A few facts:
> - Several of the apps work great under dosemu.  This is a
> good start but if
> any continued development happens, I don't want to continue
> using "DOS world"
> compilers.
> - The applications are pretty vanilla.  ie. Nothing really
> esoteric for memory
> needs or funky drivers.
> - They do use screen/cursor/keyboard control stuff.  For
> those that remember
> the DOS world that would be calls to kbhit(), cursor positioning, etc.
>
> I know that for terminal applications, ncurses is the way to
> go for cursor
> stuff.  I am studying that now.  However, I wondered if
> anyone has built or
> seen a "library" or collection of functions that interfaces
> the DOS screen
> "API" calls into ncurses calls.  I'd rather not build one if
> it is already
> out there.  Any of you heard of such a thing?  I am still
> looking around.
>
> Alan
>