FreeDOS/kernel/break.c
Bart Oldeman cf2ed6752b Had to change ctrl-c/ctrl-break handling again...
Seems to be more consistent now. read_char_sft_dev handles ^C at a fairly
high level. So raw_get_char doesn't need to worry about sft's anymore.


git-svn-id: https://svn.code.sf.net/p/freedos/svn/kernel/trunk@885 6ac86273-5f31-0410-b378-82cca8765d1b
2004-04-14 15:40:51 +00:00

94 lines
3.3 KiB
C

/****************************************************************/
/* */
/* break.c */
/* FreeDOS */
/* */
/* Control Break detection and handling */
/* */
/* Copyright (c) 1999 */
/* Steffen Kaiser */
/* All Rights Reserved */
/* */
/* This file is part of DOS-C. */
/* */
/* DOS-C is free software; you can redistribute it and/or */
/* modify it under the terms of the GNU General Public License */
/* as published by the Free Software Foundation; either version */
/* 2, or (at your option) any later version. */
/* */
/* DOS-C is distributed in the hope that it will be useful, but */
/* WITHOUT ANY WARRANTY; without even the implied warranty of */
/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See */
/* the GNU General Public License for more details. */
/* */
/* You should have received a copy of the GNU General Public */
/* License along with DOS-C; see the file COPYING. If not, */
/* write to the Free Software Foundation, 675 Mass Ave, */
/* Cambridge, MA 02139, USA. */
/****************************************************************/
#include "portab.h"
#include "globals.h"
#include "proto.h"
#ifdef VERSION_STRINGS
static BYTE *RcsId =
"$Id$";
#endif
#define CB_FLG *(UBYTE FAR*)MK_FP(0x0, 0x471)
#define CB_MSK 0x80
/* Check for ^Break/^C.
* Three sources are available:
* 1) flag at 40:71 bit 7
* 2) syscon stream (usually CON:)
* 3) i/o stream (if unequal to syscon, e.g. AUX)
*/
unsigned char ctrl_break_pressed(void)
{
return CB_FLG & CB_MSK;
}
unsigned char check_handle_break(struct dhdr FAR **pdev)
{
unsigned char c = CTL_C;
if (!ctrl_break_pressed())
c = (unsigned char)ndread(&syscon);
if (c != CTL_C && *pdev != syscon)
c = (unsigned char)ndread(pdev);
if (c == CTL_C)
handle_break(pdev, -1);
return c;
}
/*
* Handles a ^Break state
*
* Actions:
* 1) clear the ^Break flag
* 2) clear the STDIN stream
* 3) echo ^C to sft_out or pdev if sft_out==-1
* 4) decrease the InDOS flag as the kernel drops back to user space
* 5) invoke INT-23 and never come back
*/
void handle_break(struct dhdr FAR **pdev, int sft_out)
{
char *buf = "^C\r\n";
CB_FLG &= ~CB_MSK; /* reset the ^Break flag */
con_flush(pdev);
if (sft_out == -1)
cooked_write(pdev, 4, buf);
else
DosRWSft(sft_out, 4, buf, XFR_FORCE_WRITE);
if (!ErrorMode) /* within int21_handler, InDOS is not incremented */
if (InDOS)
--InDOS; /* fail-safe */
spawn_int23(); /* invoke user INT-23 and never come back */
}