xref: /openbsd/sys/lib/libkern/getsn.c (revision 5dea098c)
1 /*	$OpenBSD: getsn.c,v 1.7 2018/04/25 11:15:58 dlg Exp $	*/
2 
3 /*
4  * Copyright (c) 1996 Theo de Raadt
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <sys/types.h>
29 #include <sys/systm.h>
30 #include <dev/cons.h>
31 
32 size_t
33 getsn(char *cp, size_t size)
34 {
35 	size_t len = 0;
36 	int  c;
37 	char *lp = cp;
38 
39 	while (1) {
40 		c = cngetc();
41 		switch (c) {
42 		case '\n':
43 		case '\r':
44 			printf("\n");
45 			*lp++ = '\0';
46 			return (len);
47 		case '\b':
48 		case '\177':
49 			if (len) {
50 				printf("\b \b");
51 				--lp;
52 				--len;
53 			}
54 			break;
55 		case 'u' & 037:
56 			while (len) {
57 				printf("\b \b");
58 				--lp;
59 				--len;
60 			}
61 			break;
62 		case '\t':
63 			c = ' ';
64 		default:
65 			if (len + 1 >= size || c < ' ') {
66 				printf("\007");
67 				break;
68 			}
69 			printf("%c", c);
70 			++len;
71 			*lp++ = c;
72 		}
73 	}
74 }
75