[zbin] Fix check for existence of most recent output byte
[ipxe.git] / src / usr / prompt.c
1 /*
2 * Copyright (C) 2011 Michael Brown <mbrown@fensystems.co.uk>.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of the
7 * License, or any later version.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17 * 02110-1301, USA.
18 */
19
20 FILE_LICENCE ( GPL2_OR_LATER );
21
22 /** @file
23 *
24 * Prompt for keypress
25 *
26 */
27
28 #include <errno.h>
29 #include <stdio.h>
30 #include <ipxe/console.h>
31 #include <usr/prompt.h>
32
33 /**
34 * Prompt for keypress
35 *
36 * @v text Prompt string
37 * @v timeout Timeout period, in ticks (0=indefinite)
38 * @v key Key to wait for (0=any key)
39 * @ret rc Return status code
40 *
41 * Returns success if the specified key was pressed within the
42 * specified timeout period.
43 */
44 int prompt ( const char *text, unsigned long timeout, int key ) {
45 int key_pressed;
46
47 /* Display prompt */
48 printf ( "%s", text );
49
50 /* Wait for key */
51 key_pressed = getkey ( timeout );
52
53 /* Clear the prompt line */
54 while ( *(text++) )
55 printf ( "\b \b" );
56
57 /* Check for timeout */
58 if ( key_pressed < 0 )
59 return -ETIMEDOUT;
60
61 /* Check for correct key pressed */
62 if ( key && ( key_pressed != key ) )
63 return -ECANCELED;
64
65 return 0;
66 }