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/*
* Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program 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 of the
* License, or any later version.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <console.h>
#include <latch.h>
#include <gpxe/process.h>
#include <gpxe/keys.h>
/** @file
*
* Special key interpretation
*
*/
#define GETKEY_TIMEOUT ( TICKS_PER_SEC / 4 )
/**
* Read character from console if available within timeout period
*
* @v timeout Timeout period, in ticks
* @ret character Character read from console
*/
static int getchar_timeout ( unsigned long timeout ) {
unsigned long expiry = ( currticks() + timeout );
while ( currticks() < expiry ) {
step();
if ( iskey() )
return getchar();
}
return -1;
}
/**
* Get single keypress
*
* @ret key Key pressed
*
* The returned key will be an ASCII value or a KEY_XXX special
* constant. This function differs from getchar() in that getchar()
* will return "special" keys (e.g. cursor keys) as a series of
* characters forming an ANSI escape sequence.
*/
int getkey ( void ) {
int character;
int key;
character = getchar();
if ( character != ESC )
return character;
key = 0;
while ( ( character = getchar_timeout ( GETKEY_TIMEOUT ) ) >= 0 ) {
if ( character == '[' )
continue;
if ( ! key )
key = KEY_ANSI ( character );
if ( character >= 0x40 )
break;
}
return ( key ? key : ESC );
}
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