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
47 void
kgets(char * buf,size_t size)48 kgets(char *buf, size_t size)
49 {
50 int c;
51 char *lp;
52
53 top:
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