1 /*
2 * Copyright (C) 2006 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., 675 Mass Ave, Cambridge, MA 02139, USA.
17 */
18
19 FILE_LICENCE ( GPL2_OR_LATER );
20
21 #include <stdio.h>
22 #include <string.h>
23 #include <stdlib.h>
24 #include <console.h>
25 #include <gpxe/keys.h>
26 #include <gpxe/editstring.h>
27 #include <readline/readline.h>
28
29 /** @file
30 *
31 * Minimal readline
32 *
33 */
34
35 #define READLINE_MAX 256
36
37 static void sync_console ( struct edit_string *string ) __nonnull;
38
39 /**
40 * Synchronise console with edited string
41 *
42 * @v string Editable string
43 */
sync_console(struct edit_string * string)44 static void sync_console ( struct edit_string *string ) {
45 unsigned int mod_start = string->mod_start;
46 unsigned int mod_end = string->mod_end;
47 unsigned int cursor = string->last_cursor;
48 size_t len = strlen ( string->buf );
49
50 /* Expand region back to old cursor position if applicable */
51 if ( mod_start > string->last_cursor )
52 mod_start = string->last_cursor;
53
54 /* Expand region forward to new cursor position if applicable */
55 if ( mod_end < string->cursor )
56 mod_end = string->cursor;
57
58 /* Backspace to start of region */
59 while ( cursor > mod_start ) {
60 putchar ( '\b' );
61 cursor--;
62 }
63
64 /* Print modified region */
65 while ( cursor < mod_end ) {
66 putchar ( ( cursor >= len ) ? ' ' : string->buf[cursor] );
67 cursor++;
68 }
69
70 /* Backspace to new cursor position */
71 while ( cursor > string->cursor ) {
72 putchar ( '\b' );
73 cursor--;
74 }
75 }
76
77 /**
78 * Read line from console
79 *
80 * @v prompt Prompt string
81 * @ret line Line read from console (excluding terminating newline)
82 *
83 * The returned line is allocated with malloc(); the caller must
84 * eventually call free() to release the storage.
85 */
readline(const char * prompt)86 char * readline ( const char *prompt ) {
87 char buf[READLINE_MAX];
88 struct edit_string string;
89 int key;
90 char *line;
91
92 if ( prompt )
93 printf ( "%s", prompt );
94
95 memset ( &string, 0, sizeof ( string ) );
96 string.buf = buf;
97 string.len = sizeof ( buf );
98 buf[0] = '\0';
99
100 while ( 1 ) {
101 key = edit_string ( &string, getkey() );
102 sync_console ( &string );
103 switch ( key ) {
104 case CR:
105 case LF:
106 putchar ( '\n' );
107 line = strdup ( buf );
108 if ( ! line )
109 printf ( "Out of memory\n" );
110 return line;
111 case CTRL_C:
112 putchar ( '\n' );
113 return NULL;
114 default:
115 /* Do nothing */
116 break;
117 }
118 }
119 }
120