diff options
Diffstat (limited to 'gpxe/src/core/getkey.c')
-rw-r--r-- | gpxe/src/core/getkey.c | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/gpxe/src/core/getkey.c b/gpxe/src/core/getkey.c new file mode 100644 index 00000000..1551cf37 --- /dev/null +++ b/gpxe/src/core/getkey.c @@ -0,0 +1,79 @@ +/* + * 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 <gpxe/process.h> +#include <gpxe/keys.h> +#include <gpxe/timer.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 ); +} |