1/*	$NetBSD: gets.c,v 1.5 2016/06/11 06:49:46 dholland Exp $	*/
2
3/*-
4 * Copyright (c) 1993
5 *	The Regents of the University of California.  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 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 *	@(#)gets.c	8.1 (Berkeley) 6/11/93
32 */
33
34#include "stand.h"
35
36/*
37 * This implementation assumes that getchar() does echo, because
38 * on some machines, it is hard to keep echo from being done.
39 * Those that need it can do echo in their getchar() function.
40 *
41 * Yes, the code below will echo CR, DEL, and other control chars,
42 * but sending CR or DEL here is harmless.  All the other editing
43 * characters will be followed by a newline, so it doesn't matter.
44 * (Most terminals will not show them anyway.)
45 */
46
47void
48kgets(char *buf, size_t size)
49{
50	int c;
51	char *lp;
52
53top:
54	lp = buf;
55
56	for (;;) {
57		if (lp - buf == size) {
58			lp--;
59			*lp = '\0';
60			return;
61		}
62		c = getchar() & 0177;
63
64#ifdef	GETS_MUST_ECHO	/* Preserved in case someone wants it... */
65		putchar(c);
66#endif
67
68		switch (c) {
69
70		default:
71			*lp++ = c;
72			continue;
73
74		case '\177':
75			putchar('\b');
76			/* fall through */
77		case '\b':
78			putchar(' ');
79			putchar('\b');
80			/* fall through */
81		case '#':
82			if (lp > buf)
83				lp--;
84			continue;
85
86#ifdef	GETS_REPRINT
87		/*
88		 * This is not very useful in a boot program.
89		 * (It costs you 52 bytes on m68k, gcc -O3).
90		 */
91		case 'r'&037: {
92			char *p;
93
94			putchar('\n');
95			for (p = buf; p < lp; ++p)
96				putchar(*p);
97			continue;
98		}
99#endif
100
101		case '@':
102		case 'u'&037:
103		case 'w'&037:
104			putchar('\n');
105			goto top;
106
107		case '\r':
108			putchar('\n');
109			/* fall through */
110		case '\n':
111			*lp = '\0';
112			return;
113
114		} /* switch */
115	}
116	/*NOTREACHED*/
117}
118