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Diffstat (limited to 'roms/ipxe/src/core/getkey.c')
-rw-r--r-- | roms/ipxe/src/core/getkey.c | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/roms/ipxe/src/core/getkey.c b/roms/ipxe/src/core/getkey.c new file mode 100644 index 00000000..d69cfb44 --- /dev/null +++ b/roms/ipxe/src/core/getkey.c @@ -0,0 +1,87 @@ +/* + * 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., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +FILE_LICENCE ( GPL2_OR_LATER ); + +#include <ctype.h> +#include <ipxe/console.h> +#include <ipxe/process.h> +#include <ipxe/keys.h> +#include <ipxe/timer.h> +#include <ipxe/nap.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 (0=indefinite) + * @ret character Character read from console + */ +static int getchar_timeout ( unsigned long timeout ) { + unsigned long start = currticks(); + + while ( ( timeout == 0 ) || ( ( currticks() - start ) < timeout ) ) { + step(); + if ( iskey() ) + return getchar(); + cpu_nap(); + } + + return -1; +} + +/** + * Get single keypress + * + * @v timeout Timeout period, in ticks (0=indefinite) + * @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 ( unsigned long timeout ) { + int character; + unsigned int n = 0; + + character = getchar_timeout ( timeout ); + if ( character != ESC ) + return character; + + while ( ( character = getchar_timeout ( GETKEY_TIMEOUT ) ) >= 0 ) { + if ( character == '[' ) + continue; + if ( isdigit ( character ) ) { + n = ( ( n * 10 ) + ( character - '0' ) ); + continue; + } + if ( character >= 0x40 ) + return KEY_ANSI ( n, character ); + } + + return ESC; +} |