/* PRN device driver which truncates lines and paginates */

#define  LINES_PER_PAGE  55
#define  LINE_LENGTH     79
#define  TAB_SPACING      8

#include "dd.h"
#include <dos.h>

void init() {
request_header->status = DONE_STATUS;
}

void media_check() {bad_device_driver_function();}
void build_bpb() {bad_device_driver_function();}
void ioctl_input() {bad_device_driver_function();}
void input() {bad_device_driver_function();}
void nondestructive_input() {bad_device_driver_function();}
void input_status() {bad_device_driver_function();}
void input_flush() {bad_device_driver_function();}

static void BIOS_print(c) int c; {
union REGS r;
r.h.ah = 0;
r.h.al = c;
r.x.dx = 0;
int86(0x17, &r, &r);
if (r.h.ah&1) {
  request_header->status = ERROR_STATUS+DONE_STATUS+WRITE_FAULT;
  exit();
  }
}

static int line = 0;
static int column = 0;

static void print_character(c) int c; {
switch (c) {
  case '\t':
    do print_character(' ');
    while (column%TAB_SPACING!=0 && column<LINE_LENGTH);
    break;
  case '\f':
    BIOS_print(c);
    line = 0;
    break;
  case '\r':
    BIOS_print(c);
    column = 0;
    break;
  case '\n':
    BIOS_print(c);
    if (++line == LINES_PER_PAGE) {
      BIOS_print('\f');
      line = 0;
      }
    break;
  default:
    if (' '<=c && c<='~' && column<LINE_LENGTH) {
      BIOS_print(c);
      column++;
      }
  }
}

void output() {
int k;
for (k=0; k<request_header->x.io.count; k++)
  print_character(request_header->x.io.transfer_address[k]);
request_header->status = DONE_STATUS;
}

void output_with_verify() {bad_device_driver_function();}
void output_status() {bad_device_driver_function();}
void output_flush() {bad_device_driver_function();}
void ioctl_output() {bad_device_driver_function();}