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
38ssize_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