1 /* ----------------------------------------------------------------------- *
2 *
3 * Copyright 2004-2008 H. Peter Anvin - All Rights Reserved
4 *
5 * Permission is hereby granted, free of charge, to any person
6 * obtaining a copy of this software and associated documentation
7 * files (the "Software"), to deal in the Software without
8 * restriction, including without limitation the rights to use,
9 * copy, modify, merge, publish, distribute, sublicense, and/or
10 * sell copies of the Software, and to permit persons to whom
11 * the Software is furnished to do so, subject to the following
12 * conditions:
13 *
14 * The above copyright notice and this permission notice shall
15 * be included in all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
18 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
19 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
20 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
21 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
22 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
23 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
24 * OTHER DEALINGS IN THE SOFTWARE.
25 *
26 * ----------------------------------------------------------------------- */
27
28 /*
29 * line_input.c
30 *
31 * Line-oriented input discupline
32 */
33
34 #include "file.h"
35 #include <errno.h>
36 #include <syslinux/idle.h>
37
__line_input(struct file_info * fp,char * buf,size_t bufsize,ssize_t (* get_char)(struct file_info *,void *,size_t))38 ssize_t __line_input(struct file_info * fp, char *buf, size_t bufsize,
39 ssize_t(*get_char) (struct file_info *, void *, size_t))
40 {
41 size_t n = 0;
42 char ch;
43 int rv;
44 ssize_t(*const Write) (struct file_info *, const void *, size_t) =
45 fp->oop->write;
46
47 for (;;) {
48 rv = get_char(fp, &ch, 1);
49
50 if (rv != 1) {
51 syslinux_idle();
52 continue;
53 }
54
55 switch (ch) {
56 case '\n': /* Ignore incoming linefeed */
57 break;
58
59 case '\r':
60 *buf = '\n';
61 Write(fp, "\n", 1);
62 return n + 1;
63
64 case '\b':
65 if (n > 0) {
66 n--;
67 buf--;
68 Write(fp, "\b \b", 3);
69 }
70 break;
71
72 case '\x15': /* Ctrl-U */
73 while (n) {
74 n--;
75 buf--;
76 Write(fp, "\b \b", 3);
77 }
78 break;
79
80 default:
81 if (n < bufsize - 1) {
82 *buf = ch;
83 Write(fp, buf, 1);
84 n++;
85 buf++;
86 }
87 break;
88 }
89 }
90 }
91