xref: /freebsd/stand/libsa/gets.c (revision 3e15b01d6914c927e37d1699645783acf286655c)
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 "stand.h"
33 
34 /* gets() with constrained input length */
35 
36 void
ngets(char * buf,int n)37 ngets(char *buf, int n)
38 {
39     int c;
40     char *lp;
41 
42     for (lp = buf;;) {
43 	c = getchar();
44 	if (c == -1)
45 		break;
46 	switch (c & 0177) {
47 	case '\n':
48 	case '\r':
49 	    *lp = '\0';
50 	    putchar('\n');
51 	    return;
52 	case '\b':
53 	case '\177':
54 	    if (lp > buf) {
55 		lp--;
56 		putchar('\b');
57 		putchar(' ');
58 		putchar('\b');
59 	    }
60 	    break;
61 	case 'r'&037: {
62 	    char *p;
63 
64 	    putchar('\n');
65 	    for (p = buf; p < lp; ++p)
66 		putchar(*p);
67 	    break;
68 	}
69 	case 'u'&037:
70 	case 'w'&037:
71 	    lp = buf;
72 	    putchar('\n');
73 	    break;
74 	default:
75 	    if ((n < 1) || ((lp - buf) < n - 1)) {
76 		*lp++ = c;
77 		putchar(c);
78 	    }
79 	}
80     }
81     /*NOTREACHED*/
82 }
83 
84 int
fgetstr(char * buf,int size,int fd)85 fgetstr(char *buf, int size, int fd)
86 {
87     char	c;
88     int		err, len;
89 
90     size--;	/* leave space for terminator */
91     len = 0;
92     while (size != 0) {
93 	err = read(fd, &c, sizeof(c));
94 	if (err < 0)		/* read error */
95 	    return(-1);
96 	if (err == 0) {		/* EOF */
97 	    if (len == 0)
98 		return(-1);	/* nothing to read */
99 	    break;
100 	}
101 	if ((c == '\r') ||	/* line terminators */
102 	    (c == '\n'))
103 	    break;
104 	*buf++ = c;		/* keep char */
105 	size--;
106 	len++;
107     }
108     *buf = 0;
109     return(len);
110 }
111 
112