xref: /freebsd/stand/libsa/gets.c (revision f5463265955b829775bbb32e1fd0bc11dafc36ce)
1 /*	$NetBSD: gets.c,v 1.6 1995/10/11 21:16:57 pk 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 
32 #include <sys/cdefs.h>
33 #include "stand.h"
34 
35 /* gets() with constrained input length */
36 
37 void
38 ngets(char *buf, int n)
39 {
40     int c;
41     char *lp;
42 
43     for (lp = buf;;) {
44 	c = getchar();
45 	if (c == -1)
46 		break;
47 	switch (c & 0177) {
48 	case '\n':
49 	case '\r':
50 	    *lp = '\0';
51 	    putchar('\n');
52 	    return;
53 	case '\b':
54 	case '\177':
55 	    if (lp > buf) {
56 		lp--;
57 		putchar('\b');
58 		putchar(' ');
59 		putchar('\b');
60 	    }
61 	    break;
62 	case 'r'&037: {
63 	    char *p;
64 
65 	    putchar('\n');
66 	    for (p = buf; p < lp; ++p)
67 		putchar(*p);
68 	    break;
69 	}
70 	case 'u'&037:
71 	case 'w'&037:
72 	    lp = buf;
73 	    putchar('\n');
74 	    break;
75 	default:
76 	    if ((n < 1) || ((lp - buf) < n - 1)) {
77 		*lp++ = c;
78 		putchar(c);
79 	    }
80 	}
81     }
82     /*NOTREACHED*/
83 }
84 
85 int
86 fgetstr(char *buf, int size, int fd)
87 {
88     char	c;
89     int		err, len;
90 
91     size--;	/* leave space for terminator */
92     len = 0;
93     while (size != 0) {
94 	err = read(fd, &c, sizeof(c));
95 	if (err < 0)		/* read error */
96 	    return(-1);
97 	if (err == 0) {		/* EOF */
98 	    if (len == 0)
99 		return(-1);	/* nothing to read */
100 	    break;
101 	}
102 	if ((c == '\r') ||	/* line terminators */
103 	    (c == '\n'))
104 	    break;
105 	*buf++ = c;		/* keep char */
106 	size--;
107 	len++;
108     }
109     *buf = 0;
110     return(len);
111 }
112 
113